VEGETABLE PRODUCTION UNDER CHANGING CLIMATE SCENARIO

st st(1 September – 21 September)

2012

COMPILED AND EDITED BY

M L BhardwajH Dev SharmaManish KumarRamesh KumarSandeep KansalKuldeep Thakur

Shiv Pratap SinghDharminder Kumar

Santosh KumariMeenu GuptaVipin Sharma

FOREWORD

The importance of vegetables in providing balanced diet and nutritional security has been realised world over. Vegetables are now recognized as health food globally and play important role in overcoming micronutrient deficiencies and providing opportunities of higher farm income. The worldwide production of vegetables has tremendously gone up during the last two decades and the value of global trade in vegetables now exceeds that of cereals. Hence, more emphasis is being given in the developing countries like India to promote cultivation of vegetables. Development of hybrid varieties, integrated insect-pest and diseases management practices, integrated nutrient management and standardizing improved agrotechniques including organic farming have changed the scenario of vegetables production in the country. In short, productivity, quality and post harvest management of vegetables will have to be improved to remain competitive in the next decades. The major objectives of reducing malnutrition and alleviating poverty in developing countries through improved production and consumption of safe vegetables will involve adaptation of current vegetable systems to the potential impact of climate change. Genetic populations are being developed to introgress and identify genes conferring tolerance to stresses and at the same time generate tools for gene isolation, characterization and genetic engineering. Furthermore, agronomic practices that conserve water and protect vegetable crops from sub-optimal environmental conditions must be continuously enhanced and made easily accessible to farmers in the developing world. Current, and new, technologies being developed through plant stress physiology research can potentially contribute to mitigate threats from climate change on vegetable production. However, farmers in developing countries are usually small-holders, have fewer options and must rely heavily on available resources. Thus, technologies that are simple, affordable, and accessible must be used to increase the resilience of farms in less developed countries. Finally, capacity building and education are key components of a sustainable adaptation strategy to climate change. Hence, topic "Vegetable production under changing climate scenario" chosen for the present training under Centre of Advanced Faculty Training in Horticulture (Vegetables) is appropriate and relevant under the present circumstances of agriculture. I am sure, the lectures delivered by the faculty of this university, invited speakers as well as the exposure visits conducted during the training might have benefited the participants . Further, the giving compilation of lectures in the form of compendium to the participants of training will also help in strengthening the teaching programmes in their respective institutions in this area. All the faculty members and staff of the department of Vegetable Science deserve appreciation for the efforts made in the smooth conduct of the training programme.

(K R Dhiman)

Vice Chancellor

ACKNOWLEDGEMENTS

Vegetable being an effective alternative to protective food, have become an essential component of human diet. Although there has been spectacular increase in the vegetable production from 15 million tonnes during 1950 to 146 million tonnes during the current year, but we still need to produce more vegetables to meet the minimum requirement of at least providing 300 g of vegetables/day/captia. The target can only be achieved through combined use of growing high yielding varieties having resistance to various biotic and abiotic stresses with improved nutritional quality and matching agrotechniques by utilizing available resources. Developing countries like India whose geographical parts comprises of mountainous regions comprising of Himalayas, central plateau region, northern plains, coastal regions, deltas etc. are particularly vulnerable for climate change as little change in the climate will disturb the whole ecology and in-turn the traditional pattern of vegetables being grown in these regions. Latitudinal and altitudinal shifts in ecological and agro-economic zones, land degradation, extreme geophysical events, reduced water availability, and rise in sea level are the factors which effect the vegetable production. Unless measures are undertaken to adapt to the effects of climate change, vegetable production in the developing countries like India will be under threat. Hence, the present training programme organised by Centre of Advanced Faculty Training in Horticulture (Vegetables) on "Vegetable production under changing climate scenario" is important as it will sharpen the focus on production of vegetables under changing climatic conditions. The Centre of Advanced Faculty Training in Horticulture (Vegetables) gratefully acknowledges the patronage provided by Dr. KR Dhiman, Hon'ble Vice-Chancellor of this University. The financial assistance received from the Indian Council of Agricultural Research in conducting the training and generating useful instructional material along with assistance for need based post-graduate research is also highly acknowledged. The Centre also appreciates sincere efforts of all the resource personnel within and outside this university for interaction with the participants. All the faculty members and staff of Department of Vegetable Science, Deans and Directors of the University, other Statutory Officers and Heads of the Departments deserve special thanks for their help and co-operation in making this training programme a success.

(M L Bhardwaj)

Director, CAFT

Sr.No. Title

1. Effect of climate change on vegetable production in IndiaML Bhardwaj

2. Challenges and opportunities of vegetable cultivation under changing climate scenarioML Bhardwaj

3. High altitude protected vegetable productionBrahma Singh

4. Protected cultivation of vegetables in Indian plainsMathura Rai

5. Relevance of conservation agriculture under climate change RK Sharma

6. Production technology of ginger under changing climateH Dev Sharma and Vipin Sharma

7. Production technology of turmeric under changing climateH Dev Sharma and Vipin Sharma

8. Protected cultivation of high value vegetable cropsManish Kumar

9. Pre and post harvest factors influencing the quality of vegetable seedsHS Kanwar and DK Mehta

10. Impact of climate change on quality seed production of important temperate vegetable cropsRamesh Kumar, Sandeep Kumar, Ashok Thakur and Sanjeev Kumar

11. Vegetable production and seed production under temperate conditionsAmit Vikram

12. Production technology of cucumber under changed climatic conditionsRamesh Kumar, Sandeep Kumar, KS Thakur and Dharminder Kumar

13. Production technology of vegetable crops under changing climate with reference to organic vegetable productionKuldeep Singh Thakur, Ramesh Kumar and Dhaminder Kumar

Page(s)

1-12

13-18

19-28

29-36

37-43

44-52

53-58

59-62

63-67

68-74

75-82

83-87

88-91

CONTENTS

14. Role of biofertilizers in enhancing the vegetable productivity under organic farming systemsKuldeep Singh Thakur and Dhaminder Kumar

15. Production potential of under exploited vegetable cropsDharminder Kumar, Ramesh Kumar, KS Thakur, Ashok Thakur, Prabal Thakur and Sandeep Kumar

16. Off-season tomato production in North Western Himalayas under changing climateShiv Pratap Singh

17. Influence of climate change in capsicum productionSantosh Kumari

18. Efficient irrigation management practices in vegetable cropsJN Raina

19. Impact of climate change on vegetable crop production vis a vis mitigation and adaptation strategiesSatish Kumar Bhardwaj

20. New pathological threats to vegetable crops and their management under changing climatic conditionsRC Sharma

21. Biotic factors and their management under changing climateRC Sharma and Meenu Gupta

22. Integrated disease management in cole cropsNP Dohroo

23. Diagnosis and management of vegetable diseasesSandeep Kansal

24. Integrated disease management in solanaceous and leguminous vegetablesSandeep Kansal

25. Disease management scenario in changing climatic conditionsHarender Raj Gautam

26. Eco-friendly techniques for management of diseases in spice cropsMeenu Gupta

27. Integrated pest management in solanceous and leguminous vegetable cropsKC Sharma

92-94

95-100

101-103

104-107

108-112

113-120

121-123

124-130

131-135

136-142

143-150

151-158

159-166

167-174

28. Judicious use of pesticides to lower residue in vegetable productionRS Chandel, ID Sharma and SK Patyal

29. Management of pollinators of vegetable crops under changing climatic scenarioR K Thakur and Jatin Soni

30. Vegetable intercropping in sugarcane for greater productivity and profitabilityRK Sharma and Samar Singh

31. Role of crop modelling in mitigating effects of climate change on crop productionR S Spehia

32. Physiological disorders in vegetable crops: causes and managementSantosh Kumari

33. Weed management in vegetable cropsDharminder Kumar, Manish Kumar, Ramesh Kumar, KS Thakur, Amit Vikram and Sandeep Kumar

34. Biochemical constituents and quality attributes in spicesVipin Sharma and H Dev Sharma

35. Techniques of quality analysis in spicesVipin Sharma and H Dev Sharma

36.

List of participants

Recent techniques in postharvest management & processing of vegetables PC Sharma, Manisha Kaushal and Anil Gupta

175-181

182-188

189-195

196-202

203-208

209-217

218-222

223-227

228-234

i-ii

Effect of Climate Change on Vegetable Production in India

ML Bhardwaj

Department of Vegetable Science Dr YS Parmar University of Horticulture and Forestry, Nauni-173 230 Solan

A significant change in climate on a global scale will impact vegetable cultivation and agriculture as a whole; consequently affect the world's food supply. Climate change per se is not necessarily harmful; the problems arise from extreme events that are difficult to predict. More erratic rainfall patterns and unpredictable high temperature spells consequently reduce crop productivity. Developing countries in the tropics will be particularly vulnerable. Latitudinal and altitudinal shifts in ecological and agro-economic zones, land degradation, extreme geophysical events, reduced water availability, and rise in sea level and salinization make it difficult to cultivate the traditional vegetables in particular zones in the world. Unless measures are undertaken to mitigate the effects of climate change, food security in developing countries will be under threat and will jeopardize the future of the vegetable growers in these countries.

Vegetables are the best resource for overcoming micronutrient deficiencies and provide smallholder farmers with much higher income and more jobs per hectare than staple crops. The worldwide production of vegetables has doubled over the past quarter century and the value of global trade in vegetables now exceeds that of cereals.

Vegetables are generally sensitive to environmental extremes, and thus high temperatures and limited soil moisture are the major causes of low yields and will be further magnified by climate change.

Environmental constraints limiting vegetable productivity

Environmental stress is the primary cause of crop losses worldwide, reducing average yields for most major crops by more than 50%. The tropical vegetable production environment is a mixture of conditions that varies with season and region. Climatic changes will influence the severity of environmental stress imposed on vegetable crops. Moreover, increasing temperatures, reduced irrigation water availability, flooding, and salinity will be major limiting factors in sustaining and increasing vegetable productivity. Extreme climatic conditions will also negatively impact soil fertility and increase soil erosion. Thus, additional fertilizer application or improved nutrient-use efficiency of crops will be needed to maintain productivity or harness the potential for enhanced crop growth due to increased atmospheric CO . 2

The response of plants to environmental stresses depends on the plant developmental stage and the length and severity of the stress. Plants may respond similarly to avoid one or more stresses through morphological or biochemical mechanisms. Environmental interactions may make the stress response of plants more complex or influence the degree of impact of climate change. Measures to adapt to these climate change-induced stresses are critical for sustainable tropical vegetable production.

High temperatures

Temperature limits the range and production of many crops. In the tropics, high temperature conditions are often prevalent during the growing season and, with a changing climate, crops in this area will be subjected to increased temperature stress. Analysis of climate trends in tomato-growing locations suggests that temperatures are rising and the severity and frequency of above-optimal temperature episodes will increase in the coming decades.

Tomatoes are strongly modified by temperature alone or in conjunction with other environmental factors (Abdalla & Verkerk 1968). High temperature stress disrupts the biochemical reactions fundamental for normal cell function in plants. It primarily affects the photosynthetic functions of higher plants. High temperatures can cause significant losses in tomato productivity due to reduced fruit set, and smaller and lower quality fruits. Pre-anthesis temperature stress is associated with developmental changes in the anthers, particularly irregularities in the epidermis and endothesium, lack of opening of the stromium, and poor pollen formation. In pepper, high temperature exposure at the pre-anthesis stage did not affect pistil or stamen viability, but high post-pollination temperatures inhibited fruit set, suggesting that fertilization is sensitive to high temperature stress. Symptoms causing fruit set failure at high temperatures in tomato; includes bud drop, abnormal flower development, poor pollen production, dehiscence, and viability, ovule abortion and poor viability, reduced carbohydrate availability, and other reproductive abnormalities. In addition, significant inhibition of photosynthesis occurs at temperatures above optimum, resulting in considerable loss of potential productivity.

Drought

Unpredictable drought is the single most important factor affecting world food security and the catalyst of the great famines of the past. The world's water supply is fixed, thus increasing population pressure and competition for water resources will make the effect of successive droughts more severe. Inefficient water usage all over the world and inefficient distribution systems in developing countries further decreases water availability. Water availability is expected to be highly sensitive to climate change and severe water stress conditions will affect crop

2

productivity, particularly that of vegetables. In combination with elevated temperatures, decreased precipitation could cause reduction of irrigation water availability and increase in evapo-transpiration, leading to severe crop water-stress conditions. Vegetables, being succulent products by definition, generally consist of greater than 90% water (AVRDC 1990). Thus, water greatly influences the yield and quality of vegetables; drought conditions drastically reduce vegetable productivity. Drought stress causes an increase of solute concentration in the environment (soil), leading to an osmotic flow of water out of plant cells. This leads to an increase of the solute concentration in plant cells, thereby lowering the water potential and disrupting membranes and cell processes such as photosynthesis. The timing, intensity, and duration of drought spells determine the magnitude of the effect of drought.

Salinity

Vegetable production is threatened by increasing soil salinity particularly in irrigated croplands which provide 40% of the world's food. Excessive soil salinity reduces productivity of many agricultural crops, including most vegetables which are particularly sensitive throughout the ontogeny of the plant. According to the United States Department of Agriculture (USDA), onions are sensitive to saline soils, while cucumbers, eggplants, peppers, and tomatoes, amongst the main crops moderately sensitive. In hot and dry environments, high evapo-transpiration results in substantial water loss, thus leaving salt around the plant roots which interferes with the plant's ability to uptake water. Physiologically, salinity imposes an initial water deficit that results from the relatively high solute concentrations in the soil,

+ +causes ion-specific stresses resulting from altered K /Na ratios, and leads to a build + -

up in Na and Cl concentrations that are detrimental to plants. Plant sensitivity to salt stress is reflected in loss of turgor, growth reduction, wilting, leaf curling and epinasty, leaf abscission, decreased photosynthesis, respiratory changes, loss of cellular integrity, tissue necrosis, and potentially death of the plant. Salinity also affects agriculture in coastal regions which are impacted by low-quality and high-saline irrigation water due to contamination of the groundwater and intrusion of saline water due to natural or man-made events. Salinity fluctuates with season, being generally high in the dry season and low during rainy season when freshwater flushing is prevalent. Furthermore, coastal areas are threatened by specific, saline natural disasters which can make agricultural lands unproductive, such as tsunamis which may inundate low-lying areas with seawater. Although the seawater rapidly recedes, the groundwater contamination and subsequent osmotic stress causes crop losses and affects soil fertility. In the inland areas, traditional water wells are commonly used for irrigation water in many countries. The bedrock deposit contains salts and the water from these wells are becoming more saline, thus affecting irrigated vegetable production in these areas.

3

Flooding

Vegetable production occurs in both dry and wet seasons in the tropics. However, production is often limited during the rainy season due to excessive moisture brought about by heavy rain. Most vegetables are highly sensitive to flooding and genetic variation with respect to this character is limited, particularly in tomato. In general, damage to vegetables by flooding is due to the reduction of oxygen in the root zone which inhibits aerobic processes. Flooded tomato plants accumulate endogenous ethylene that causes damage to the plants. Low oxygen levels stimulate an increased production of anethylene precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), in the roots. The rapid development of epinastic growth of leaves is a characteristic response of tomatoes to water-logged conditions and the role of ethylene accumulation has been implicated. The severity of flooding symptoms increases with rising temperatures; rapid wilting and death of tomato plants is usually observed following a short period of flooding at high temperatures.

The Need for Adaptation to Climate Change

Potential impacts of climate change on agricultural production will depend not only on climate per se, but also on the internal dynamics of agricultural systems, including their ability to adapt to the changes. Success in mitigating climate change depends on how well agricultural crops and systems adapt to the changes and concomitant environmental stresses of those changes on the current systems. Farmers in developing countries of the tropics need tools to adapt and mitigate the adverse effects of climate change on agricultural productivity, and particularly on vegetable production, quality and yield. Current, and new, technologies being developed through plant stress physiology research can potentially contribute to mitigate threats from climate change on vegetable production. However, farmers in developing countries are usually small-holders, have fewer options and must rely heavily on resources available in their farms or within their communities. Thus, technologies that are simple, affordable, and accessible must be used to increase the resilience of farms in less developed countries. AVRDC – The World Vegetable Center has been working to address the effect of environmental stress on vegetable production. Germplasm of the major vegetable crops which are tolerant of high temperatures, flooding and drought has been identified and advanced breeding lines are being developed. Efforts are also underway to identify nitrogen-use efficient germplasm. In addition, development of production systems geared towards improved water-use efficiency and expected to mitigate the effects of hot and dry conditions in vegetable production systems are top research and development priorities.

4

Enhancing Vegetable Production Systems

Various management practices have the potential to raise the yield of vegetables grown under hot and wet conditions of the lowland tropics. AVRDC – The World Vegetable Center has developed technologies to alleviate production challenges such as limited irrigation water and flooding, to mitigate the effects of salinity, and also to ensure appropriate availability of nutrients to the plants. Strategies include modifying fertilizer application to enhance nutrient availability to plants, direct delivery of water to roots (drip irrigation), grafting to increase flood and disease tolerance, and use of soil amendments to improve soil fertility and enhance nutrient uptake by plants.

Water-saving irrigation management

The quality and efficiency of water management determine the yield and quality of vegetable products. The optimum frequency and amount of applied water is a function of climate and weather conditions, crop species, variety, stage of growth and rooting characteristics, soil water retention capacity and texture, irrigation system and management factor. Too much or too little water causes abnormal plant growth, predisposes plants to infection by pathogens, and causes nutritional disorders. If water is scarce and supplies are erratic or variable, then timely irrigation and conservation of soil moisture reserves are the most important agronomic interventions to maintain yields during drought stress. There are several methods of applying irrigation water and the choice depends on the crop, water supply, soil characteristics and topography. Application of irrigation water could be through overhead, surface, drip, or sub-irrigation systems. Surface irrigation methods are utilized in more than 80% of the world's irrigated lands yet its field level application efficiency is often 40-50%. To generate income and alleviate poverty of the small-holder farmers in developing countries, AVRDC – The World Vegetable Center and other institutions promote affordable, small-scale drip irrigation technologies developed by the International Development Enterprises (IDE). Drip irrigation delivers water directly to plants through small plastic tubes. IDE states that water losses due to run-off and deep percolation are minimized and water savings of 50-80% are achieved when compared to most traditional surface irrigation methods. Crop production per unit of water consumed by plant evapo-transpiration is typically increased by 10-50%. Thus, more plants can be irrigated per unit of water by drip irrigation, and with less labor. In Nepal, cauliflower yields using low-cost drip irrigation were not significantly different from those achieved by hand watering; however the long-term economic and labor benefits were greater using the low-cost drip irrigation. The water-use efficiency by chili pepper was significantly higher in drip irrigation compared to furrow irrigation, with higher efficiencies observed with high delivery rate drip irrigation regimes (AVRDC 2005). For drought tolerant crop

5

like watermelon, yield differences between furrow and drip irrigated crops were not significantly different; however, the incidence of Fusarium wilt was reduced when a lower drip irrigation rate was used. In general, the use of low-cost drip irrigation is cost effective, labor-saving, and allows more plants to be grown per unit of water, thereby both saving water and increasing farmers' incomes at the same time.

Cultural practices that conserve water and protect crops

Various crop management practices such as mulching and the use of shelters and raised beds help to conserve soil moisture, prevent soil degradation, and protect vegetables from heavy rains, high temperatures, and flooding. The use of organic and inorganic mulches is common in high-value vegetable production systems. These protective coverings help reduce evaporation, moderate soil temperature, reduce soil runoff and erosion, protect fruits from direct contact with soil and minimize weed growth. In addition, the use of organic materials as mulch can help enhance soil fertility, structure and other soil properties. Rice straw is abundant in rice-growing areas of the tropics and generally recommended for summer tomato production. The benefits of rice straw mulch on fruit yield of tomato have been demonstrated in Taiwan (AVRDC 1981). In India, mulching improved the growth of eggplant, okra, bottle gourd, round melon, ridge gourd, and sponge gourd compared to the non-mulched. Yields were the highest when polythene and sarkanda (Saccharum spp. and Canna spp.) were used as mulching materials. In the lowland tropics where temperatures are high, dark-colored plastic mulch is recommended in combination with rice straw. Dark plastic mulch prevents sunlight from reaching the soil surface and the rice straw insulates the plastic from direct sunlight thereby preventing the soil temperature rising too high during the day. During the hot rainy season, vegetables such as tomatoes suffer from yield losses caused by heavy rains. Simple, clear plastic rain shelters prevent water logging and rain impact damage on developing fruits, with consequent improvement in tomato yields. Fruit cracking and the number of unmarketable fruits are also reduced. Elimination of flooding and rain damage, as well as the reduced air temperature, was responsible for the higher yields of the crops grown under plastic shelters. Another form of shelter using shade cloth can be used to reduce temperature stress. Shade shelters also prevent damage from direct rain impact and intense sunlight. Planting vegetables in raised beds can ameliorate the effects of flooding during the rainy season (AVRDC 1979, 1981). Yields of tomatoes increased with bed height, most likely due to improved drainage and reduction of anoxic stress.

Improved stress tolerance through grafting

Grafting vegetables originated in East Asia during the 20th century and is currently common practice in Japan, Korea and some European countries. Grafting,

6

in this context, involves uniting of two living plant parts (rootstock and scion) to produce a single growing plant.

It has been used primarily to control soil-borne diseases affecting the production of fruit vegetables such as tomato, eggplant, and cucurbits. However, it can provide tolerance to soil-related environmental stresses such as drought, salinity, low soil temperature and flooding if appropriate tolerant rootstocks are used. Grafting of eggplants was started in the 1950s, followed by grafting of cucumbers and tomatoes in the 1960s and 1970s. it was found that melons grafted onto hybrid squash rootstocks were more salt tolerant than the non-grafted melons. However, tolerance to salt by rootstocks varies greatly among species, such that rootstocks from Cucurbita spp. are more tolerant of salt than rootstocks from Lagenaria siceraria. Grafted plants were also more able to tolerate low soil temperatures. Solanum lycopersicum x S. habrochaites rootstocks provide tolerance of low soil

o otemperatures (10 C to 13 C) for their grafted tomato scions, while eggplants grafted onto S. integrifolium x S. melongena rootstocks grew better at lower temperatures

o o(18 C to 21 C) than non-grafted plants.

Vegetables generally are unable to tolerate excessive soil moisture. Tomatoes in particular are considered to be one of the vegetable crops most sensitive to excess water. In the tropics, heavy rainfall with poor drainage induces water-logged conditions that reduce oxygen availability in the soil thereby causing wilting, chlorosis, leaf epinasty, and ultimately death of the tomato plants. Genetic variability for tolerance of excess soil moisture is limited or inadequate to prevent losses. Research at AVRDC - The World Vegetable Center has shown that many accessions of eggplant are highly tolerant of flooding. Thus, the Center developed grafting techniques to improve the flood tolerance of tomato using eggplant rootstocks which were identified with good grafting compatibility with tomato and high tolerance to excess soil moisture. Tomato scions grafted onto eggplant rootstock grow well and produce acceptable yields during the rainy season. In addition to protection against flooding, some eggplant genotypes are drought tolerant and eggplant rootstocks can therefore provide protection against limited soil moisture stress.

Developing Climate-Resilient Vegetables

Improved, adapted vegetable germplasm is the most cost-effective option for farmers to meet the challenges of a changing climate. However, most modern cultivars represent a limited sampling of available genetic variability including tolerance to environmental stresses. Breeding new varieties, particularly for intensive, high input production systems in developed countries is required to be done.

7

Superior varieties adapted to a wider range of climatic conditions could result from the discovery of novel genetic variation for tolerance to different biotic and abiotic stresses. Genotypes with improved attributes conditioned by superior combinations of alleles at multiple loci could be identified and advanced. Improved selection techniques are needed to identify these superior genotypes and associated traits, especially from wild, related species that grow in environments which do not support the growth of their domesticated relatives that are cultivated varieties. Plants native to climates with marked seasonality are able to acclimatize more easily to variable environmental conditions and provide opportunities to identify genes or gene combinations which confer such resilience.

Tolerance to high temperatures

The World Vegetable Center has developed tomatoes and Chinese cabbage with general adaptation to hot and humid tropical environments and low-input cropping systems since the early 1970s. This has been achieved by developing heat-tolerant and disease-resistant breeding lines. The Center has made significant contributions to the development of heat-tolerant tomato and Chinese cabbage lines and the subsequent release of adapted, tropical varieties worldwide. The key to achieving high yields with heat tolerant cultivars is the broadening of their genetic base through crosses between heat tolerant tropical lines and disease resistant temperate or winter varieties. The heat tolerant tomato lines were developed using heat tolerant breeding lines and landraces from the Philippines (e.g. VC11-3-1-8, VC 11-2-5, Divisoria-2) and the United States (e.g. Tamu Chico III, PI289309). However, lower yields in the heat tolerant lines are still a concern.

More heat tolerant varieties are required to meet the needs of a changing climate, and these must be able to match the yields of conventional, non-heat tolerant varieties under non-stress conditions. A wider range of genotypic variation must be explored to identify additional sources of heat tolerance. An AVRDC - breeding line, CL5915, has demonstrated high levels of heat tolerance in Southeast Asia and the Pacific. The fruit set of CL5915 ranges from 15% - 30% while there is complete

oabsence of fruit set in heat-sensitive lines in mean field temperatures of 35 C.

Drought tolerance and water-use efficiency

Plants resist water or drought stress in many ways. In slowly developing water deficit, plants may escape drought stress by shortening their life cycle. However, the oxidative stress of rapid dehydration is very damaging to the photosynthetic processes, and the capacity for energy dissipation and metabolic protection against reactive oxygen species is the key to survival under drought conditions. Tissue tolerance to severe dehydration is not common in crop plants but is found in species native to extremely dry environments. Genetic variability for

8

drought tolerance in S. lycopersicum is limited and inadequate. The best source of resistance is from other species in the genus Solanum. The Tomato Genetics Resource Center (TGRC) at the University of California, Davis has assembled a set of the putatively stress tolerant tomato germplasm that includes accessions of S. cheesmanii, S. chilense, S. lycopersicum, S. lycopersicum var. cerasiforme, S. pennellii, S. peruvianum and S. pimpinellifolium. S. chilense and S. pennelli are indigenous to arid and semi-arid environments of South America. Both species produce small green fruit and have an indeterminate growth habit. S chilense is adapted to desert areas of northern Chile and often found in areas where no other vegetation grows. S. chilense has finely divided leaves and well-developed root system. S. chilense has a longer primary root and more extensive secondary root system than cultivated tomato. Drought tests show that S. chilense is five times more tolerant of wilting than cultivated tomato. S. pennellii has the ability to increase its water use efficiency under drought conditions unlike the cultivated S. lycopersicum (O'Connell et al. 2007). It has thick, round waxy leaves, is known to produce acyl-sugars in its trichomes, and its leaves are able to take up dew. Transfer and utilization of genes from these drought resistant species will enhance tolerance of tomato cultivars to dry conditions, although wide crosses with S. pennellii produce fertile progenies, S. chilense is cross-incompatible with S. lycopersicum and embryo rescue through tissue culture is required to produce progeny plants. Research at AVRDC and other institutions is in progress to identify the genetic factors underlying drought tolerance in S. chilense and S. pennellii, and to transfer these factors into cultivated tomatoes.

Tolerance to saline soils and irrigation water

Attempts to improve the salt tolerance of crops through conventional breeding programs have very limited success due to the genetic and physiologic complexity of this trait. In addition, tolerance to saline conditions is a developmentally regulated, stage-specific phenomenon; tolerance at one stage of plant development does not always correlate with tolerance at other stages. Success in breeding for salt tolerance requires effective screening methods, existence of genetic variability, and ability to transfer the genes to the species of interest. Most commercial tomato cultivars are moderately sensitive to increased salinity and only limited variation exists in cultivated species.

Genetic variation for salt tolerance during seed germination in tomato has been identified within cultivated and wild species. In pepper, salt stress significantly decreases germination, shoot height, root length, fresh and dry weight, and yield. Pepper genotypes Demre, Ilica 250, 11-B-14, Bagci Carliston, Mini Aci Sivri, Yalova Carliston, and Yaglik 28 can be useful as sources of genes to develop pepper

9

cultivars with improved germination under salt stress. Related wild tomato species have shown strong salinity tolerance and are sources of genes as coastal areas are common habitat of some wild species. Studies have identified potential sources of resistance in the wild tomato species S. cheesmanii, S. peruvianum, S pennelii, S. pimpinellifolium, and S. habrochaites. Attempts to transfer quantitative trait loci (QTLs) and elucidate the genetics of salt tolerance have been conducted using populations involving wild species. Elucidation of mechanism of salt tolerance at different growth periods and the introgression of salinity tolerance genes into vegetables would accelerate development of varieties that are able to withstand high or variable levels of salinity compatible with different production environments.

Climate-Proofing through Genomics and Biotechnology

Increasing crop productivity in unfavorable environments will require advanced technologies to complement traditional methods which are often unable to prevent yield losses due to environmental stresses. In the past decade, genomics has developed from whole genome sequencing to the discovery of novel and high throughput genetic and molecular technologies. Genes have been discovered and gene functions understood. This has opened the way to genetic manipulation of genes associated with tolerance to environmental stresses. These tools promise more rapid, and potentially spectacular, returns but require high levels of investment. Many activities using these genetic and molecular tools are in place, with some successes. National and international institutes are re-tooling for plant molecular genetic research to enhance traditional plant breeding and benefit from the potential of genetic engineering to increase and sustain crop productivity.

QTLs and gene discovery for tolerance to stresses

Genetic enhancement using molecular technologies has revolutionized plant breeding. Advances in genetics and genomics have greatly improved our understanding of structural and functional aspects of plant genomes.

The use of molecular markers as a selection tool provides the potential for increasing the efficiency of breeding programs by reducing environmental variability, facilitating earlier selection, and reducing subsequent population sizes for field testing. Molecular markers facilitate efficient introgression of superior alleles from wild species into the breeding programs and enable the pyramiding of genes controlling quantitative traits. Thus, enhancing and accelerating the development of stress tolerant and higher yielding cultivars for farmers in developing countries. Molecular marker analysis of stress tolerance in vegetables is limited but efforts are underway to identify QTLs underlying tolerance to stresses.

10

Prioritizing Vegetable Research to Address Impact of Climate Change

It is unlikely that a single method to overcome the effects of environmental stresses on vegetables will be found. A systems approach, where all available options are considered in an integrated manner, will be the most effective and ultimately the most sustainable, particularly for developing countries in the tropics under a variable climate. This holistic strategy will need global integration of efforts; the resulting synergies will produce impact more quickly than the individual institutions working in isolation could accomplish. For this to succeed, adequate and long-term funding is necessary, scientific results have to be delivered, best approaches utilized and effective methods sustained to deliver global public goods for impact.

AVRDC - The World Vegetable Center, as the world's leading international center focused on vegetable research and development, has expanded its research to further address the potential challenges posed by climate change. The Center's success in its major objectives of reducing malnutrition and alleviating poverty in developing countries through improved production and consumption of safe vegetables will involve adaptation of current vegetable systems to the potential impact of climate change. Vegetable germplasm with tolerance to drought, high temperatures and other environmental stresses, and ability to maintain yield in marginal soils must be identified to serve as sources of these traits for both public and private vegetable breeding programs. This germplasm will include both cultivated and wild accessions possessing genetic variation unavailable in current, widely-grown cultivars. Genetic populations are being developed to introgress and identify genes conferring tolerance to stresses and at the same time generate tools for gene isolation, characterization, and genetic engineering.

Furthermore, agronomic practices that conserve water and protect vegetable crops from sub-optimal environmental conditions must be continuously enhanced and made easily accessible to farmers in the developing world. Finally, capacity building and education are key components of a sustainable adaptation strategy to climate change.

Enhancing adaptation of tropical production systems to changing climatic conditions is a huge undertaking. It requires the combined efforts of many national and international institutions and an effective and efficient strategy to be able to deliver technologies that can mitigate the effects of climate change on the diverse crops and production systems. The scientific information and technologies developed through these initiatives must be readily accessible, consolidated and utilized in a strategic way. This can only be achieved through collaboration, complementarily, and coordinated objectives to address the consequences of climate change on the world's crop production.

11

References

Abdalla AA, Verderk K (1968) Growth, flowering and fruit set of tomato at high temperature. The Neth J Agric Sci 16:71-76.

AVRDC (1990) Vegetable Production Training Manual. Asian Vegetable Research and Training Center. Shanhua, Tainan, 447 pp.

AVRDC (1979) Annual Report. Asian Vegetable Research and Development Center. Shanhua, Taiwan. 173 pp.

AVRDC (1981) Annual Report. Asian Vegetable Research and Development Center. Shanhua, Taiwan. 84 pp.

AVRDC (2005) Annual Report. AVRDC – The World Vegetable Center. Shanhua, Taiwan.

12

Challenges and Opportunities of Vegetable Cultivation under Changing Climate Scenario

ML Bhardwaj

Department of Vegetable Science Dr YS Parmar University of Horticulture and Forestry, Nauni-173 230 Solan

The world's farmers are challenged with growing abundant, safe and nutritious food for an increasing global population in the face of changing climate and pest pressures. To enable them to continue to produce food sustainably, they need to have broad access to appropriate innovations, as well as the knowledge and skills to make these new tools valuable on the farm. India produces 133.5 millions tones of vegetables from an area of 7.9 million hectares (NHB, 2010). According to statistics release by Ministry of Agriculture, there has been 13.5% increase in area and 13.4% increase in vegetable output during the period 1996 to 2010. India is the second largest producer of vegetables in the world, next to China. India's share of the world vegetable market is around 14%. India is endowed with quite a diverse climatic condition, which enables production of more than 50 indigenous and exotic vegetables. India ranks first in peas and cauliflower production and is the second largest producer of onion, brinjal and cabbage. In spite of all these achievements, per capita consumption of vegetables in India is very low against WHO standards (180 g/day/capita against 300 g/day capita recommended by FAO). Iron deficiency, anaemia is quite wide spread in our country, the prevalence varying from 45 per cent in adult males to 70 per cent or more in women and children. There is an urgent need for providing health security to our population by supplying nutrition through balanced diet.

Vegetables are rich source of vitamins, carbohydrates, salts and proteins. With increased health awareness in the general public and changing dietary patterns, vegetables are now becoming an integral part of average household's daily meals. In addition, high population growth rate has also given rise to high demand in basic dietary vegetables. Increased health awareness, high population growth rate, changing dietary patterns of increasingly affluent middle class and availability of packaged vegetables, has therefore generated a year round high demand for vegetables in the country in general and in major city centres in particular. However, our farmers have yet not been able to in cash this opportunity and still follow traditional sowing and picking patterns. This results in highly volatile vegetable supply market wherein the market is flooded with seasonal vegetables irrespective of demand presence on one hand and very high priced vegetables in off-season on the

other. Lack of developed vegetable processing and storage facility robs our farmers from their due share of profit margins. In natural season local vegetables flood the markets substantially bringing down the prices. In the absence of storage infrastructure and vegetable processing industry in the country, off-season vegetables farming is the only viable option that can add value to the farmer produce.

There is a huge demand for fresh vegetables in the local as well as international markets, which includes Europe, Middle East, and Far Eastern markets but due to their perishable nature it is difficult to export this commodity. The facility of growing off-season vegetables also allows for growing non-conventional varieties of vegetables, which are in high demand in the international market. Vegetables can be cultivated in off-season, with the induction of an artificial technique like greenhouse technology, in which temperature and moisture is controlled for specific growth of vegetables. The production of vegetables all around the year enables the growers to fully utilize their resources and supplement income from vegetable growing as compared to other normal agricultural crops. Hybrid seeds that provide higher yield can lead to lower unit cost. Higher prices can be obtained by producing the right crops, at the right times and of better quality. They may also depend on negotiating skills and targeting high price buyers. Since, the land holding of farmers is decreasing, there is a need to increase the productivity of available land, off-season vegetable farming is a measure through which we can attain higher profit margins from the crop.

Challenges:

Climate change poses significant challenges and negative impacts upon for the present vegetable production. There is mounting evidence that smallr farmers in developing countries are experiencing increased climate variability and climatic change include more extreme events like average means of temperature and precipitation which is clearly linked to increased greenhouse gas (GHG) emissions.

Extreme Weather Physiological impact Crops affected

High temperatures in

summer

Reproductive (flower)

development impaired

Peas, Tomatoes, Seed

Production

Crop development and

yield impaired

Vegetable Brassicas,

Tomatoes

Crop quality impaired Tomatoes, Vegetable

Brassicas

High temperatures in

winter

Cold hardiness limited Seed production

14

Global climate change especially erratic rainfall pattern and unpredictable high temperature spells will reduce the productivity of vegetable crops. Developing countries in the tropics will be affected very much. Latitudinal and altitudinal shifts in different agro ecological zones, land degradation, extreme geophysical events, reduced water availability, rise in sea level and salinization are postulated.

Among vegetable crops, tomatoes are the most important vegetable crops worldwide and grown over 4 million hectare of land area. Tomato, cabbage, onion, hot pepper and egg plant are important in Asia. In Asia, yields are highest in the east because of temperate and sub-temperate climate and the productivity is lowest in the hot and humid low lands of South East Asia. The extreme climatic conditions will affect soil fertility and increase soil erosion. So, additional fertilizers application or improved nutrient efficiency of crop will be needed to harness the potential for enhanced crop growth due to increased atmosphere CO . In the tropical areas, high 2

temperature conditions are prevalent in the growing season and with the changing climate crops will be subjected to temperature stress. High temperature affects the photosynthetic functions of plants and cause irregularities in the epidermis and endothesium, lack of opening of the stromium and poor pollen formation especially in case of tomato. In pepper, high post-pollination inhibits fruit set. In tomato, overall productivity is reduced by high temperatures due to bud drop, abnormal flower development, poor pollen production, dehiscence and viability, ovule abortion, poor viability, reduced carbohydrate availability, other reproductive abnormalities and above all inhibition of photosynthesis.

Unpredictable drought affects world food security and cause great famines. Insufficient use of water all over the world and inefficient distribution system in developing countries decrease water availability. High temperature in combination with low precipitation could reduce the irrigation water availability and increase the evapo-transpiration leading to severe crop water stress particularly in vegetables which contain more than 90% water and ultimately influences the yield and quality. Drought causes an increase in solute concentration in the soil environment leading to an osmotic flow of water out of the plant cells which subsequently leads to an increase of solute concentration in plant cells and so, finally lowers the water potential and disrupts membranes and cell processes such as photosynthesis.

Salt stress in plants is reflected in loss of turgor, growth reduction, wilting, leaf curling and epinasty, leaf abscission, decrease photosynthesis, respiratory changes, loss of cellular integrity, tissue necrosis and ultimately death of plants. Sometimes, vegetable production is also affected by heavy rainfall especially crops like tomato. Flooding reduces the oxygen level in the root zone inhibiting aerobic processes. Generally, flooded tomato plants accumulated endogenous ethylene that causes damage to the plants. Low oxygen levels stimulate an increased of an ethylene

15

precursor, 1-aminocyclopropane-1-carboxlic acid in the roots. In combination with high temperatures, flooding causes rapid wilting and death of plants. Yield potential of majority of vegetable crops is affected by various climatic factors like temperature, solar radiations, humidity, rainfall, wind, drought, salinity etc

Causes of climate change

·Deforestation·Fossil fuel consumption·Urbanisation·Land reclamation·Agricultural intensification·Freshwater extraction·Fisheries overexploitation·Waste production (Ericksen, 2008)

Opportunities of vegetable production

India is endowed with a wide range of agro-climatic conditions from tropical to temperate which makes it ideal for off-season vegetable production throughout the year. The hill states offer most congenial climatic conditions for off-season vegetable production during summer months for vegetables like tomato, capsicum, peas, beans, cole crops, root crops and cucumber. The main season vegetables of these hilly regions become off-season in the plains as result growers fetch lucrative returns from their produce. Off-season vegetables produced in the hills have a special significance because of specific flavour, aroma, freshness, prolonged self-life and keeping quality. These being environment specific are primarily confined to hilly areas of the country. The increase in area and production under off season vegetables in the last 3-4 decades may be because of increase in income level of consumers, change in dietary habit inclusion of more vegetables in food menu, urbanization, awareness of both farmers and consumers etc. Moreover, there exists a scope for increasing the off-season exotic vegetable production for domestic and international markets. Further, off-season vegetable production helps to bridge the seasonal gap between demand and supply and provides more employment opportunities to marginal and small hilly farmers.

In Himachal Pradesh, agriculture plays an important role in the economy of Himachal Pradesh as 67 per cent of the total population depends on agriculture for its livelihood. Only 11 per cent of the total geographical area is available for agriculture, out of which 80 per cent is rain-fed and the holdings are small and scattered. Despite all these barring factors, climate of the state, especially in the hilly regions, is congenial for the cultivation of many off-season vegetables, horticultural and floricultural crops. In the valley areas of the district Kullu, the acreage of cereal crops

16

has declined from 59 per cent to 5 per cent but has been recompensed by vegetable crops over a period from 1990-91 to 2002-03 (Bala and Sharma, 2005). Farmers have tapped underground water sources through bore wells, tube-wells and hand pumps, to meet their water requirement.

In the state, several vegetables grown in the summer- kharif season are harvested at a time when they can't be produced in the plains. These off-season vegetables have a definite market advantage and provide assured better returns to the farmers. The valley areas of the state have become famous for the production of quality peas, cabbage, cauliflower, French bean and capsicum. Also, being short-duration crops, 3-4 crops of vegetables can be taken by the farmers in the mid-hills per annum to augment their income. According to Thakur (1994) “Off-season vegetable production and marketing is the most profitable farm business giving very high production and income to farmers per unit area of land”. A system approach will thus be the most effective and sustainable for the developing countries in the tropics under a variable climate which will cover collection and improvement of wild species tolerance to drought, high temperature and other environment stresses using gene isolation, characterization and genetic engineering, stresses on effective delivery methodology to transfer technologies and disseminate knowledge and strategies on capacity building and education

Conclusions

·Climate change will lead to more periods of high temperature and periods of heavy rain.

·Unseasonal or extreme weather will have an increasing impact on crop production.

·There are already examples of what to expect.

·Modelling can help predict consequences and guide adaptation.

·Development of production system, improved varieties with improved water use efficiency.

·Screening and validation of the cloned genes in model crops such as tomato.

·Patenting elite genes and promoters

·In India, diverse climatic conditions, available across the country provide ample opportunity to grow almost all types of vegetable crops, thus making our country the second largest producer of vegetables.

0·An average increase of 1 C could affect the phenology of crop by influencing

degree-day. Understanding, the likely impact of increase in temperature and CO on vegetable crops is the first step in developing sound adaptation 2

strategies to address the adverse impact of climate change.

17

References:

Arya Prem Singh. 2000. Off-season vegetable growing in hills. APH Publishing Corporation, New Delhi. 427p.

Bala Brij, Sharma Nikhil and Sharma R K. 2011. Cost and return structure for the promising enterprise of off-season vegetables in Himachal Pradesh. Agricultural Economics Research Review 24: 141-148.

De L C and Bhattacharjee S K. 2011. Handboook of vegetable crops. Pointer Publishers; Jaipur. pp. 27-31.

Ericksen P. 2008. Climate Change and Food Security. Environmental Change Institute University of Oxford. UK.

Ghosh S P. 2012. Carrying Capacity Of Indian Agriculture. Current Science. 102 (6): 889-893.

IPCC. 2001. Climate change 2001: Impacts, adaptation and vulnerability. Intergovermental Panel on Climate Change. New York, USA.

Liliana H. 2011. The Impacts of Climate Change on Food Production; A 2020 Perspective. United Nations Framework Convention on Climate Change. ISBN; USA.

Mishra G P, Singh Narendra, Kumar Hitesh and Singh Shashi Bala. 2010. Protected Cultivation for Food and Nutritional Security at Ladakh. Defence Science Journal 61 (2): 219-225.

18

High Altitude Protected Vegetable Production

Brahma Singh

Advisor, World Noni Research Foundation, ChennaiFormer Director, Life Sciences, DRDO, New Delhi

The topic has two major aspects. First one is high altitudes meaning inhabited areas 7000 feet above mean sea level. High altitudes are known for difficult environment from vegetable production point of view. The second one is protected vegetable production meaning vegetable production using protected agriculture technologies where ever necessitated. Both the aspects require brief elaboration before describing details of the topic.

HIGH ALTITUDES

In Indian Himalaya, high altitudes are of two types from their climate point of view. First one is cold and humid high altitudes spread over mainly in Uttaranchal, Sikkim, West Bengal and Arunachal Pradesh and other North East States. The other one is cold arid high altitudes mainly spread over in Jammu and Kashmir-the Ladakh region and Himachal Pradesh-Lahual-Spiti and Kinnaur area. Himachal Pradesh and Jammu and Kashmir have sizeable area under cold humid high altitudes also. The climatic conditions in cold humid and cold arid high altitudes are different necessitating different type of protected agriculture. Altitudes in Indian Himalayas range between 200 to more than 5000 meter above mean sea level. Winters in high altitudes are severe and prolonged restricting vegetable production season from 7 to 2.5 months or less as given below.

Table -1. Vegetable production period at different altitudes

Altitude met ers above mean sea level

Period Month

2670 April-October 7.0

3000

May-Mid October

5.5

3300

Mid May –Mid September

4.0

4000

Mid June –August 2.5

Sub-zero temperatures result in snowfall in higher altitudes. It could result in dry cold or wet along with rainfall or snow. In Ladakh and Lahaul-Spiti cold arid desert permafrost occurs with frozen upper soil (mostly sandy). In these areas ambient minimum temperatures are below or near freezing for almost five months. The relative humidity during this period is in the range of 45-60%. In Leh valley average minimum temperature from November to April is sub-zero and can be as low as minus 16 ? C. Wind velocity in the afternoon is very high resulting in dust storm or snow blizzards. The authors had an opportunity to work in these areas for more than a decade. This article is based mainly on their experience on cold desert.

PROTECTED VEGETABLE PRODUCTION th

The area under greenhouse cultivation, reported by the end of 20 century was about 110 ha. in India and world over 275,000 hectare (Mishra, et al 2010). During last decade this area must have increased by 10 per cent if not more. In Europe, Spain is leading in protected agriculture with 51,000 ha mostly under low cost poly houses. In Asia, China has the largest area under protected cultivation, 2.5 M ha under poly house/greenhouse. Protected vegetable production is important component of protected agriculture. Protected vegetable production is practiced throughout the world irrespective of altitude of the place since several hundred years. River bed production of early cucurbits prevalent in India since ages , is protected agriculture. It involves protection of production stages of vegetables mainly from adverse environmental conditions such as temperature, hail, scorching sun, heavy rains, snow etc. In fact the need to protect the crops against unfavorable environmental conditions led to the development of protected agriculture. This is now becoming important due to climate change. Greenhouse is the most practical method of achieving the objectives of protected agriculture, where natural environment is modified by using sound engineering principles to achieve optimum plant growth and yield. Besides protected technology has potential to produce more produce per unit area with increased input use efficiency. There is need to increase nutritionally rich vegetable production and productivity of seasonal and non-season crops in our country. Research results have shown that by adopting protected cultivation productivity of vegetable crops can be increased by 3 to 5 times as compared to open environment. This aspect needs to be extensively exploited in India as has been done elsewhere in the world. To promote this Indo-Israel protected vegetable production projects in the country are serving the purpose. NAIP program of ICAR is giving due importance to this aspects besides different public and private organizations. Areas having uncongenial environment for vegetable production can also be converted into potential vegetable production centers with the help of protected agriculture technologies and techniques as has been discussed in this article. Needless to emphasize that better quality produce is obtained under protected conditions.

20

ADVANTAGES OF PROTECTED VEGETABLE CULTIVATION

Protected vegetable production can reduce the amount of water and chemicals used in production of high value vegetables compared to open field conditions. The comparative advantages are:

1. Vegetables can be produced year round regardless of season. Adverse climate for production of vegetables can be overcome by different systems of protected production.

2. Multiple cropping on the same piece of land is possible.

3. Off season production of vegetables to get better return to growers is feasible.

4. It allows production of high quality and healthy seedlings of vegetables for transplanting in open field supporting early crop, strong and resistant crop stands.

5. Protective structures provide protection to high value crops from unfavorable weather conditions, pests and diseases.

6. Use of protected vegetable cultivation can increase production by more than five folds and increase productivity per unit of land, water, energy and labour.

7. Protected cultivation supports the production of high quality and clean products.

8. It makes cultivation of vegetables possible in areas where it is not possible in open conditions such as high altitudes deserts.

9. It makes vertical cultivation of vegetables possible using technologies like hydroponics, aeroponics etc and use of vertical beds for production.

10. Disease free seed production of costly vegetables becomes easy under protected structures.

LIMITATIONS

1. Manual or hand pollination in cross pollinated vegetables like cucurbits or development of their parthenocarpic hybrids/varieties.

2. Expensive, short life and non-availability of cladding materials.

3. Lack of appropriate tools and machinery.

4. Structure cost initially looks unaffordable. Farmers with zero risk affordability do not come forward to adopt it.

5. Inadequate support from planners and scientists- suitable varieties/hybrids

21

and their production packages for protected production systems are either not available or very few. Protected structures in use are not scientifically designed; hence potentials of structure are not fully exploited.

METHODS OF PROTECTED VEGETABLE PRODUCTION IN HIGH ALTITUDES

The major protected cultivation methods at high altitudes of India in vogue are use of:

1. Poly houses/Greenhouse/net house/shade house

2. Low tunnels/row Covers

3. Plastic Mulching

POLYHOUSES/GREENHOUSES/NETHOUSES/SHADEHOUSES

Poly house/greenhouse is a framed structure having 200 micron (800 gauges) UV stabilized transparent or translucent low density polyethylene or other claddings which create greenhouse effect making microclimate favorable for plant growth and development. Structure is large enough to permit a person to work inside. The structure can be made in different shape and size using locally available materials or steel or aluminum or bricks or their combinations for its frame.

In Ladakh poly houses are made above ground ( poly house), underground (soil trench) and a combination of two (polyench). Above ground poly houses are generally made of mud wall or unbaked brick wall on three sides. North side wall is made 7 feet high, east and west side walls are made with gradual slope to south having entrance on either side. Southern side is covered with polyethylene supported on locally available willow or poplar wood frames. Water for irrigation is stored inside but underground for convenience.

The underground trench type poly house is made with suitable dimensions, generally 5-10x3-4x 1m with polyethylene cladding supported on wooden poles or GI pipes.

A combination of both-construction of poly house above trench, known as polyench is being found better than both in winter months for production of vegetables where soil and sun heat is harnessed for maintaining required higher temperature inside. Polyench can be single or double walled.

Poly houses are constructed using GI pipe of 25-75 mm diameter with a wall thickness of 2mm. These structures are fastened by welding, nuts and bolts or

22

clamped. Foundation for posts, size of hoops and perlins are worked out on engineering principles. Good cladding material (low density polyethylene, diffused or relatively translucent films, cross laminated, anti-fog, anti-drip, anti-sulphur types, fiber reinforced plastics, polycarbonates etc) is essential to ensure good life of greenhouse. Poly carbonate and FRP cladding green houses have also been found useful for covering large area.. During winter month solar heat is harnessed for production of leafy and other vegetables and vegetable nursery. The temperatures inside different protected structures during winter are higher than open field to the extent of supporting plant life.

Insect proof net and shading materials are used to keep insects at bay and to lower temperatures in summer if considered necessary. Net and shade houses are used for vegetable production as protected structures elsewhere in lower altitudes in the country.

LOW TUNNELS OR ROW COVERS

Transparent plastic films or nets are stretched over low (1m or so) hoops made of steel wires, bamboo or willow twigs or cane or any other locally available suitable material to cover rows of plants in the field providing protection against unfavorable environment like low temperature, frost, wind, insect-pests etc. Different types of claddings are available in the market. Low tunnels with plastic mulch and drip irrigation are becoming popular for several vegetable crops production.

PLASTIC MULCHING

Mulching is a practice of covering soil around plants which makes growing conditions more favorable by conserving soil moisture, maintaining higher soil temperature, preventing weeds and allowing soil micro flora to be favorably active. In other areas organic mulches such as leaves, bark, peat, wooden chips, straw etc are used but in high altitudes particularly in arid high altitudes plastic is used for mulching which has unimaginably significantly contributed to vegetable production there.

Plastic mulching is one of the widely used practices in protected agriculture particularly in vegetable production. It has following advantages:

1. It conserves soil moisture by preventing water evaporation from it.

2. It prevents germination of annual weeds because of its opaqueness.

3. Plastic mulches maintain a warm temperature during night which facilitates an early establishment of seedlings by strong root system or germination of seeds.

23

4. Soil water erosiopn is minimized.

5. Plastic mulches serve for longer period. They can be used for more than one season.

6. Provides cleaner crop produce.

7. More income through early, higher and quality yields.

CONTRIBUTION OF PROTECTED CULTIVATION ON ARID HIGH ALTITUDE VEGETABLE PRODUCTION

Arid high altitudes of Ladakh and Lahaul and Spiti in early sixties used to grow root vegetables like radish, turnip, carrot, beet root; potato and mongol palak (beet leaf). After Chinese aggression (1962), induction of Indian defence forces in these areas necessitated local production of different vegetables. Defence Research and Development Organization (DRDO) through its laboratory, Field Research Laboratory now Defence Institute of High Altitude Research, Leh did pioneering research. With the help of protected agriculture technologies it could have been possible to grow now all short of vegetables there during agriculture season (May to September or mid October). Perhaps first glass house in high altitudes of the country was erected in Leh (11500 ft amsl) in 1964.

Some of the major contributions made by DRDO in developing protected vegetable production technologies are as follows:

1.Protected vegetable nursery production making cultivation of several vegetables possible

Early production of vegetable nursery under different protected structures during March and April ( minimum atmospheric temperature is sub-zero) and transplanting them in May and June with and without plastic mulch extended agriculture period and made possible cultivation of cabbage, cauliflower, knoll-khol, broccoli, brussel's sprouts, tomato, brinjal, chili, capsicum and onion possible. Use of plastic mulch enabled early, quality and higher yield of these vegetables. In mulched crop low pressure (gravity/slope) drip irrigation and fertigation is possible as experimented by DRDO. In this way most of the vegetables are being grown on large scale making the area surplus in cabbage, something unbelievable. Early and late production of vegetables with the help of protected technology has also been standardized which extends availability period of locally produced vegetables-an important aspect there.

2. Making Cucurbits production possible in cold desert

Till early 1990s cucurbits cultivation in open in Ladakh was considered impossible. But growing seedlings in poly pouch under poly houses during April-

24

May and transplanting them in open field with plastic mulch made it possible to grow almost all cucurbits in Leh. This has not only improved vegetable basket in the area but also added variety to food basket of local inhabitants and soldiers. Commercial production of cucurbits in cold desert of India is now possible through protected cultivation. Sarda melon imported in large quantity in the country can be produced in these areas with ease. Production of off season (August and September) muskmelon, watermelon etc in open fields has also become possible. An early crop of cucurbits like squash, longmelon etc is also taken in poly houses.

3. Sub-zero atmosphere vegetable production

As stated earlier during winter these areas remain cut off with main land due to heavy snow fall. Only air communication is on during winter months. Through air transportation of bulky and perishable commodities like vegetables is not only expensive but very difficult. In Ladakh sector Army alone spends several crores of rupees only on transportation of vegetables. Cost of transportation is more than the cost of vegetables. Hence local production through protected cultivation is being successfully promoted there. This is being encouraged by harnessing solar energy both thermal and photovoltaic and making heating of greenhouses possible. The geothermal energy sources available in the area are potential source of heating greenhouses. Remoteness of these sources is coming in the way of their exploitation

4. Vegetable Seed production

Seed production of biennial crops like temperate varieties of cole crops, root crops, and onion used to take two years or 18 months in these areas. First year normal crop is grown and stored underground during long winters. Second year in summer they are planted for seed production. By the protected agriculture technology now it has become possible to produce seeds of these varieties in half the time by raising early crop under protected structure and transplanting them in open fields for seed production. Pusa Himani radish, long day onions, Nantes carrot and others respond well to this technique. Production of seeds of temperate varieties of vegetables in India is a problem due to lack of consorted research and development efforts?

Future Prospects

To ensure nutritional security along with food security to the ever growing population of the country it is essential to double production of vegetable crops in the country. Major constraint is increased pressure on cultivable lands near metros where vegetables are generally grown. This is due to urbanization and industrialization which is also essential. Therefore, it is at most necessary to improve the productivity of vegetables adopting protected cultivation in the country in general and high altitudes in particular.

25

Protected cultivation of vegetables in high altitudes of Himalaya has been practiced successfully indicating its potential to deal with conditions created by climate change scenario in the country. Protection against adverse climatic conditions for plant growth has become universal necessity. Protection of plant growth and development against adverse physical (temperature, rain and wind and biological (insects and diseases) factors through protected agriculture technologies is going to be uncommon in near future because of climate change and advantages of protected cultivation. There is need to develop area specific, most appropriate, efficient and affordable protected structures with cheaper and durable cladding materials. Emphasis would be shifted on development of suitable varieties and hybrids of vegetables for protected cultivation under organic and inorganic production protocols. Vegetable nurseries would be produced under protected structures both at individual farmer and commercial nurseries level. Tools and machinery for protected cultivation would be developed and become common. Vertical or multitier farming of vegetables would be developed to make use of protected space. High altitudes are likely to be harnessed for large scale vegetable production under protected structures. Human resource development on protected agriculture and Government support for its promotion should be taken up through State Agriculture Universities and department of horticulture. Plastic mulching coupled with drip irrigation in vegetable production is going to be a common practice because their proven advantages. There is emphasis on development of suitable varieties of vegetables which have high production and productivity under protected conditions in high altitudes and other places. Production protocols of particular variety of a vegetable like cucumber, capsicum and tomato are being developed for different structures in different climates and conditions.

Summary

High altitudes in India are reasonably populated with local tribes and troops. Vegetable production for them during winter months when environment mainly temperature is unfavorable for their growth, has been discussed. Protected production technologies or green house technologies developed for these areas such as use of local poly house, both underground and above ground along with combination of both have been discussed. Production of leafy vegetables under subzero atmosphere, cucurbits and almost all vegetables in cold arid high altitudes of Ladakh using protected agriculture technology has been mentioned in brief. Production of almost all vegetable crops during limited agriculture season from May to September in cold desert of Ladakh, considered remote possibility has now become possible with the help of protected agriculture technologies. Future prospects of protected cultivation of vegetable crops in high altitudes and elsewhere have been highlighted.

26

References:

Dhaulakhandi, A. B. and Singh, B. (1999) Winter performance of greenhouse attached passive solar heated hut at high altitude. SESI, Journal 9(2):105-114.

Mishra, G. P., Singh, N. and Kumar,H. and Singh, S. B. (2010) Protected Cultivation for Food and Nutritional Security at Ladakh Defence Science Journal, Vol. 61, No. 2, March 2010, pp. 219-225

NAAS 2010. “Protected Agriculture in North-West Himalayas”. Policy Paper No. 47, National Academy of Agricultural Sciences, New Delhi. pp16.

Singh, B. (1995) Vegetable Production in Ladakh. Field Research Laboratory, Leh. India

Singh, B. and Dhaulakhandi, A. B. (1998). Application of solar greenhouse for vegetable production in cold desert in renewable energy. Energy Efficiency Policy and the Environment. Elsevier Science Ltd, UK, P2511-314

Singh, B., Dwivedi, S K. and Chaurasia, O.P.(2004). Improvement in production and productivity of horticultural crops in cold arid regions of India. Proceedings of the first Indian Horticulture Congress, 6-9 November, 2004, The Horticultural Society of India, New Delhi, India, viii+ 764p

Singh, B., Dwivedi, S. K. and Plajor, E. (2000). Studies on suitability of various structures for winter vegetable production at sub-zero temperatures. Acta Hort., 517:309-14.

Singh, B., Dwivedi, S. K. and Sharma J. P. (2000). Greenhouse technology for winter vegetable cultivation in cold arid zones. In: Dynamics of cold arid Agriculture (Eds J. P. Sharma and A. A. Mir) Kalayani Publishers, Judhiana. PP 279-293.

Singh, B., Dwivedi, S.K., Singh, N. and Paljor, E. (1999). Sustainable Horticulture practices for cold arid areas. In : The Himalayan Environment. eds. SK Dash & J Bahadur . New age International (P) Ltd, Publishers – New Delhi. pp 235 – 245.

Singh, B. and Dwivedi, S. K. (2002). Vegetable production potential in Ladakh. In: Vegetable growing in India. Eds. P. S. Arya and Sant Prakash. Kalyani Publishers, New Delhi. pp 87-93.

Singh, B., Dwivedi, SK. and Sharma, JP. (2000 a). Greenhouse technology for winter vegetable cultivation in cold arid zones. In: dynamics of cold arid agriculture. Eds. J.P. sharma and A.A. Mir, kalyani publishers-Ludhiana, pp. 279-293.

Singh,B. (1999) Vegetable production in cold desert of India: a success story on solar greenhouses. Acta horticulture 534: 205-12.

27

Singh, N. and Singh, B. ( 2003). Ladakh mein sabji utpadan (Vegetable Production in Ladakh. Field Research Laboratory, Leh.pp 139

Singh, B. and Singh, N (2011) High altitudes protected cultivation of vegetables. Seminar on protected cultivation at GB Pant University of Agriculture and Technology, Pantnagar, Udham Singh Nagar, Uttarakhand.

28

Protected Cultivation of Vegetables in Indian Plains

Mathura Rai

Former Director, Indian institute of Vegetable Research Varanasi 1/36 Rashmikhand, Shardanagar, Lucknow-226 002, UP

Vegetable growers can substantially increase their income by cultivation of vegetables under protected condition during off-season as the vegetables produced during their normal season generally do not fetch good returns due to availability of these vegetable in the markets. Off-season cultivation of cucurbits under low plastic tunnels is one of the most profitable technologies under northern plains of India. Walk-in tunnels are also suitable and effective to raise off-season nursery and off-season vegetable cultivation due to their low initial cost. Insect proof net houses provides virus free ideal conditions for productions of tomato, chilli, sweet pepper and other vegetables mainly during the rainy season. These low cost structures are also suitable for growing pesticide-free green vegetables. Low cost greenhouses can be used for high quality vegetable cultivation for long duration (6-10 months) mainly in peri-urban areas of the country. Polytrenches have also been proved extremely useful for growing vegetables under cold desert conditions in upper Himalayas in the country. Poly house/ Greenhouses are frames of inflated structure covered with a transparent material in which crops are grown under controlled environment conditions. Greenhouse cultivation as well as other modes of controlled environment cultivation has been evolved to create favorable micro-climates, which favors the crop production could be possible all through the year or part of the year as required. The primary environmental parameter traditionally controlled is temperature, usually providing heat to overcome extreme cold conditions. However, environmental control can also include cooling to mitigate excessive temperatures, light control either shading or adding supplemental light, carbon dioxide levels, relative humidity, water, plant nutrients and pest control.

Status of Greenhouse Cultivation

Commercial greenhouses with climate controlled devices are very few in the country. Solar greenhouses comprising of glass and polyethylene houses are becoming increasingly popular both in temperate and tropical regions. In early sixties, Field Research Laboratory (FRL) of DRDO at Leh attempted solar greenhouse vegetable production research and made an outstanding contribution to the extent that almost every rural family in Leh valley possesses a polyhouse these days. Indian Petro Chemical Corporation Ltd (IPCL) boosted the greenhouse

research and application for raising vegetables by providing Ultra Violet (UV) stabilized cladding film and Aluminium polyhouse structures. Several private seed production agencies have promoted greenhouse production of vegetables. In comparison to other countries, India has very little area under greenhouses.

Classification of greenhouse based on suitability and cost

a) Low cost or low tech greenhouse

Low cost greenhouse is a simple structure constructed with locally available materials such as bamboo, timber stone pillars, etc. The ultra violet (UV) film is used as cladding materials. Unlike conventional or hi-tech greenhouses, no specific control device for regulating environmental parameters in-side the greenhouse are provided. Simple techniques are, however, adopted for management of the temperature and humidity. Even light intensity can be reduced by incorporating shading materials like nets. The temperature can be reduced during summer by opening the side walls. Such structure is used as rain shelter as well as to protect from low temperature for crop cultivation. Otherwise, inside temperature is increased when all sidewalls are covered with plastic film. This type of greenhouse is mainly suitable for cold climatic zone.

b) Medium-tech greenhouse

Greenhouse users prefers to have manually or semiautomatic control arrangement owing to minimum investment. This type of greenhouse is constructed using galvanized iron (G.I) pipes. The canopy cover is attached with structure with the help of screws. Whole structure is firmly fixed with the ground to withstand the disturbance against wind. Exhaust fans with thermostat are provided to control the temperature. Evaporative cooling pads and misting arrangements are also made to maintain a favourable humidity inside the greenhouse. As these system are semi-automatic, hence, require a lot of attention and care, and it is very difficult and cumbersome to maintain uniform environment throughout the cropping period. These greenhouses are suitable for dry and composite climatic zones.

c) Hi-tech greenhouse

To overcome some of the difficulties in medium-tech greenhouse, a hi-tech greenhouse where the entire device, controlling the environment parameters, are supported to function automatically. At present computer based advance technology with full automaton for temperature, humidity, irrigation control is available which can be utilized for high value low volume vegetable for local consumption and long distance supply.

Shade house

Shade houses are used for the production of plants in warm climates or during summer months. Nurserymen use these structures for the growth of hydrangeas and

30

azaleas during the summer months. Apart from nursery, flowers and foliages which require shade can also be grown in shade houses. E.g. Orchids, These shade structures make excellent holding areas for field-grown stock while it is being prepared for shipping to retail outlets. Shade houses are most often constructed as a pole-supported structure and covered with either lath (lath houses) or polypropylene shade fabric. Polypropylene shade nets with various percentages of ventilations are used. Black, green, and white colored nets are used, while black colours are the most preferred as it retains heat outside.

Heating of Polyhouse

Heating is required in winter season. Generally, the solar energy is sufficient to maintain inner temperature of polyhouse but some times more temperature is required to be supplied to some crops. For this few methods are as follows:

i. Constructing a tunnel below the earth of poly house.

ii. Covering the northern wall of the house by jute clothing.

iii. Covering whole of the polyhouse with jute cloth during night

iv. Fitting solar energy driven device in polyhouse.

Cooling of Polyhouse0In summer season, when ambient temperature rises above 40 C during day

time the cooling of polyhouse is required by the following measures, not only the temperature but also relative humidity of polyhouse can also be kept within limit.

i. Removing the internal air or polyhouse out of it in a natural manner.

ii. Changing the internal air into external air by putting the fan on.

iii. Installation of cooler on eastern or Western Wall not only keeps temperature low but maintains proper humidity also.

iv. Running water-misting machine can control the temperature of the polyhouse

Cladding material

Polythene proves to be an economical cladding material. Now long lasting, unbreakable and light roofing panels-UV stabilized clear fiber glass and polycarbonate panels are available. Plastics are used in tropical and sub-tropical areas compared to glass/fiberglass owing to their economical feasibility.

Plastics create enclosed ecosystems for plant growth. LDPE (low density polyethylene) / LLDPE (linear low density polyethylene) will last for 3-4 years compared to polythene without UV stabilizers.

31

32

Plant growing structures / containers in greenhouse production

The duration of crop in greenhouse is the key to make the greenhouse technology profitable or the duration of production in greenhouses should be short. In this context, use of containers in greenhouse production assumes greater significance. The containers are used for the following activities in greenhouse production

Advantages of containers in greenhouse production

Increase in production capacity by reducing crop time.

High quality of the greenhouse product

Uniformity in plant growth with good vigor

Provide quick take off with little or no transplanting shock.

Easy maintenance of sanitation in greenhouse

Easy to handle, grade and shift or for transportation

Better water drainage and aeration in pot media.

Easy to monitor chemical characteristics and plant nutrition with advance irrigation systems like drips.

Drip irrigation and fertigation systems in greenhouse cultivation

The plant is required to take up very large amounts of water and nutrients, with a relatively small root system, and manufacture photosynthates for a large amount of flower per unit area with a foliar system relatively small in relation to required production.

Watering system

Micro irrigation system is the best for watering plants in a greenhouse. Micro sprinklers or drip irrigation equipments can be used. Basically the watering system should ensure that water does not fall on the leaves or flowers as it leads to disease and scorching problems. In micro sprinkler system, water under high pressure is forced through nozzles arranged on a supporting stand at about 1 feet height. This facilitates watering at the base level of the plants.

Equipments required for drip irrigation system include

i) A pump unit to generate 2.8kg/cm2 pressure

i) Water filtration system – sand/silica/screen filters

iii) PVC tubing with dripper or emitters

Drippers of different types are available

i) Labyrinth drippers

ii) Turbo drippers

iii) Pressure compensating drippers – contain silicon membrane which assures uniform flow rate for years

iv) Button drippers- easy and simple to clean. These are good for pots, orchards and are available with side outlet/top outlet or micro tube out let

v) Pot drippers – cones with long tube

Water output in drippers

a. 16mm dripper at 2.8kg/cm2 pressure gives 2.65 liters/hour (LPH).

b. 15mm dripper at 1 kg/cm2 pressure gives 1 to 4 liters per hour

Filters: Depending upon the type of water, different kinds of filters can be used.

Gravel filter: Used for filtration of water obtained for open canals and reservoirs that are contaminated by organic impurities, algae etc. The filtering is done by beds of basalt or quartz.

Hydrocyclone: Used to filter well or river water that carries sand particles.

Disc flitersL: Used to remove fine particles suspended in water

Screen filters: Stainless steel screen of 120 mesh ( 0.13mm) size. This is used for second stage filtration of irrigation water.

Fertigation system

In fertigation system, an automatic mixing and dispensing unit is installed which consists of three systems pump and a supplying device. The fertilizers are dissolved separately in tanks and are mixed in a given ratio and supplied to the plants through drippers.

Fertilizers: Fertilizer dosage has to be dependent on growing media. Soilless mixes have lower nutrient holding capacity and therefore require more frequent fertilizer application. Essential elements are at their maximum availability in the pH range of 5.5 to 6.5. In general Micro elements are more readily available at lower pH ranges, while macro elements are more readily available at pH 6 and higher.

Forms of inorganic fertilizers: Dry fertilizers, slow release fertilizer and liquid fertilizer are commonly used in green houses.

Slow release fertilizer: They release the nutrient into the medium over a period of several months. These fertilizer granules are coated with porous plastic. When the granules become moistened the fertilizer inside is released slowly into the root medium. An important thing to be kept in mind regarding these fertilizers is that, they should never be added to the soil media before steaming or heating of media. Heating melts the plastic coating and releases all the fertilizer into the root medium at once. The high acidity would burn the root zone.

33

Liquid fertilizer: These are 100 per cent water soluble. These comes in powdered form. This can be either single nutrient or complete fertilizer. They have to be dissolved in warm water to desired concentration.

Fertilizer application methods:

1. Constant feed: sLow concentration at every irrigation are much better. This provides continuous supply of nutrient to plant growth and results in steady growth of the plant. Fertilization with each watering is referred as fertigation.

2. Intermittent application: Liquid fertilizer is applied in regular intervals of weekly, biweekly or even monthly. The problem with this is wide variability in the availability of fertilizer in the root zone. At the time of application, high concentration of fertilizer will be available in the root zone and the plant immediately starts absorbing it. By the time next application is made there will be less availability of nutrient. This fluctuation results in uneven plant growth rates, even stress and poor quality crop.

Fertilizer injectors

This device inject small amount of concentrated liquid fertilizer directly into the water lines so that green house crops are fertilized with every watering.

Multiple injectors

Multiple injectors are necessary when incompatible fertilizers are to be used for fertigation. Incompatible fertilizers when mixed together as concentrates form solid precipitates. This would change nutrient content of the stock solution and also would clog the siphon tube and injector. Multiple injectors would avoid this problem. These injectors can be of computer controlled H.E. ANDERSON is one of the popular multiple injector.

Fertilizer Injectors

Fertilizer injectors are of two basic types: Those that inject concentrated fertilizer into water lines on the basis of the venturi principle and those that inject using positive displacement

A. Venturi Principle Injectors

1. Basically these injectors work by means of a pressure difference between the irrigation line and the fertilizer stock tank.

a) The most common example of this is the HOZON proportioner.

b) Low pressure, or a suction, is created at the faucet connection of the Hozon at the suction tube opening. This draws up the fertilizer from the stock tank and is blended in to the irrigation water flowing through the Hozon faucet connection.

34

c) The average ratio of Hozon proportioners is 1:16. However, Hozon proportioners are not very precise as the ratio can vary widely depending on the water pressure.

d) These injectors are inexpensive and are suitable for small areas. Large amounts of fertilizer application would require huge stock tanks due to its narrow ratio.

B. Positive displacement injectors:

1. These injectors are more expensive than Hozon types, but are very accurate in proportioning fertilizer into irrigation lines regardless of water pressure.

2. These injectors also have a much broader ratio with 1:100 and 1:200 ratio being the most common. Thus, stock tanks for large applications areas are of manageable size and these injectors have much larger flow rates.

3. Injection by these proportioners is controlled either by a water pump or an electrical pump.

4. Anderson injectors are very popular in the greenhouse industry with single and multiple head models.

a. Ratios vary from 1:100 to 1:1000 by means of a dial on the pump head for feeding flexibility.

b. Multihead installations permit feeding several fertilizers simultaneously without mixing. This is especially significant for fertilizers that are incompatible (forming precipitates, etc.) when mixed together in concentrated form.

5. Dosatron feature variable ratios (1:50 to 1:500) and a plain water bypass

. 6. Plus injectors also feature variable ratios (1:50 to 1:1000) and operates on water pressure as low as 7 GPM.

7. Gewa injectors actually inject fertilizer into the irrigation lines by pressure.

a. The fertilizer is contained in a rubber bag inside the metal tank.Water pressure forces the fertilizer out of the bag into the water supply.

b. Care must be taken when filling the bags as they can tear.

c. Ratios are variable from 1:15 to 1:300.

8. If your injector is installed directly in a water line, be sure to install a bypass around the injector so irrigations of plain water can be accomplished.

Pinching

Pinching operation should be done after one month of transplanting. In general, maintaining the two shoots per plant has been found effective.

35

Developing devices for monitoring through internet

Control and monitoring of environmental parameters inside a Polyhouse farm, so as to ensure continuous maintenance of favorable crop atmosphere is very essentia. The concept encompasses data acquisition of thermal process parameters through a sensor network, data storage, post processing and online transmission of data to multiple users logged on to their respective web-browsers. Further, control of process parameters of a Polyhouse (for example, toggle on/off control of pumps and accessories, louvers and ventilators, air flow rate, sunlight management, etc.) from one or more remote monitoring stations over the web server in real time is also integrated. A graphical user interface (GUI) is unified for the ease of operations by the farming community. System also allows transmission of process parameters, including emergency alarm signals via e-mail client server or alternatively sending a SMS on a mobile phone. A conventional chat has also been integrated with the GUI to add vibrancy to inter-user communication. This feature can be embedded in upcoming 3G mobile technology. Simulations and video tutorials can also be integrated in the web server for teaching the farming community. Such integrated approach greatly widens the socio-economic possibilities for farmers through interaction with modern technological resources (Sonawane et al., 2008)

References:

Sonawane,Y. R. , Khandekar, S., Mishra , B.K. and Soundra Pandian, K. K. (2008). Environment Monitoring and Control of a Polyhouse Farm through Internet. World Bank: India Country Overview 2008 pp1-6

Wani, K.P. Pradeep Kumar Singh, Asima Amin*, Faheema Mushtaq and Zahoor Ahmad Dar (2011). Protected cultivation of tomato, capsicum and cucumber under Kashmir valley conditions Asian Journal of Science and Technology,1(4):056-061.

36

Relevance of Conservation Agriculture under Climate Change

RK Sharma

Directorate of Wheat Research, Karnal – 132 001, Haryana, India

Agriculture in India was focused on achieving food security through increased area under high yielding varieties, expansion of irrigation and increased use of external inputs like chemical fertilisers and pesticides. With the unabated increase in population, more and more land will be required for urbanization, and productivity needs to be increased to meet the increasing domestic and industrial demand. A decline in land productivity has been observed over the past few years. Moreover, due to indiscriminate use, or rather misuse, of natural resources especially water has led to groundwater pollution as well as depletion of groundwater resources (Nayar and Gill 1994). Depleting soil organic carbon status, decreasing soil fertility and reduced factor productivity are other issues of concern (Yadav 1998). These evidences indicate the weakening of natural resource base. If we continue to exploit the natural resources at the current level, productivity and sustainability is bound to suffer. Therefore, to achieve sustainable higher productivity, efforts must be focussed on reversing the trend in natural resource degradation by adopting efficient resource conservation agriculture practices.

Laser land levelling is a pre-requisite for enhancing the benefits of the resource conservation practices. Generally, fields are not properly levelled leading to poor performance of the crop, because, part of area suffers due to water stress and part due to excess of water. After laser levelling the field, it has been observed that yield enhances from 10 to 25 per cent. The higher yields are due to proper crop stand, uniform water distribution, crop growth and uniform maturity. In addition to higher yield, the savings of water, a scarce resource, is from 35-45 per cent due to higher application efficiency, increased nutrient use efficiency by 15-25 per cent, reduces weed problem and increases the cultivable area by 3 to 6 per cent due to reduction in area required for bunds and channels (Jat et al. 2004).

Conservation agriculture

Conservation agriculture is much more than just reducing the mechanical tillage. In a soil that is not tilled for many years, the crop residues remain on the soil surface and produce a layer of mulch. This layer protects the soil from the physical impact of rain and wind, conserves soil moisture, moderates soil temperature and harbours a number of organisms, from larger insects down to soil borne fungi and bacteria. These organisms help convert the crop residues into humus and contribute to the physical stabilization of the soil structure and buffering of water and nutrients.

Most tillage operations targeted at loosening the soil lead to mineralization and reduction of soil organic matter, a substrate for soil life. Thus, agriculture with reduced mechanical tillage is only possible when soil organisms are taking over the task of tilling the soil. This, however, leads to other implications regarding the use of chemical farm inputs. In a system with reduced mechanical tillage based on mulch cover and biological tillage, alternatives have to be developed to control pests and weeds. Therefore, “Integrated Pest Management” becomes mandatory. One important element to achieve this is crop rotation, interrupting the infection chain between subsequent crops. Synthetic chemical, particularly herbicides, are inevitable during initial years but have to be used with care to reduce the negative impacts on soil life. A new balance between pests and beneficial organisms, crops and weeds, gets established and the farmer learns to manage the cropping system with reduced use of synthetic pesticides and mineral fertilizer compared to "conventional" farming.

Hence, “Conservation Agriculture” (CA) involves a complete change in the crop production system, although the entry point is reduction of mechanical soil tillage. It involves modifications in the machinery, which means more mechanisation, maintenance of surface residues providing at least 30% soil cover, minimum soil disturbance, adjustment, if required, in the cropping system, minimum and need based use of chemicals.

Why seeding into crop residues?

Burning of crop residues and ploughing of soil is mainly considered necessary phytosanitary measures controlling pests, diseases and weeds. Leaving crop residues on the soil surface seems to be a much better option than incorporation or burning as it reduces soil erosion and soil water evaporation, avoids short-term nutrient tie up, and suppresses weeds. Moreover, the slower decomposition also helps build up soil organic carbon (Unger 1991; Sharma et al. 2008). Tillage is mainly practised to prepare seedbed and to control already germinated weeds. But the tillage is also responsible for stimulation of the weed germination and emergence of many weeds by brief exposure to light (Ballard et al. 1992). Crop residues may influence the weed seed reserve in the soil directly or indirectly and also the efficiency of soil-applied herbicides (Crutchfield et al. 1986). Moreover, incorporated plant residues may release the allelochemicals, which can be toxic to weeds (Inderjit and Keating 1999). Residue retention on the soil surface in combination with no till system may also significantly contribute to the suppression of weeds (Chhokar et al. 2009). No till system reduce the weed emergence by avoiding exposure to light as well as offering mechanical impedance. Residue retention also influences soil temperature and soil moisture, which in turn may increase or decrease the weed germination depending on type of weed flora, soil

38

conditions, type of crop residue and quantity. At lower residue level, weed flora may be higher than the residue free conditions but at higher levels definitely the weed will be reduced considerably.

Goal of CA

Conservation Agriculture aims to conserve, improve and make more efficient use of natural (soil, water and biological) resources and external inputs and contributes to environmental conservation along with enhanced and sustained agricultural production.

Characteristics of CA

Conservation Agriculture maintains a permanent or semi-permanent organic soil cover. This can be a growing crop or the plant residues. Its function is to protect the soil physically from sun, rain and wind as well as to feed the soil biota. The soil micro-organisms and soil fauna takes over the tillage function and soil nutrient balancing. As the mechanical tillage disturbs this process, the zero or minimum tillage and direct seeding are important elements of CA. A varied crop rotation is also important to avoid disease and pest problems. Rather than incorporating biomass such as green manures, cover crops or crop residues, it is left on soil surface in CA. The dead biomass serves as physical protection and as substrate for the soil fauna. In this way mineralization is reduced and suitable soil levels of organic matter are built up and maintained.

What is not CA?

Zero-tillage: Zero tillage as stand alone is not Conservation Agriculture but is an important component of CA. Tillage is avoided in CA by forcing the seed with appropriate direct drills into the soil, by maintaining a soil cover. This also improves soil structure, facilitates direct planting and uses biological tillage. Nevertheless, zero tillage can be transition step towards CA.

Conservation tillage: It is a practice to open the soil surface to increase rain water infiltration and reduce erosion. However, it still depends on tillage as the soil structure-forming element.

Direct planting/seeding: This is only a technique that refers to seeding/planting without preparing a proper seedbed. The same equipment is used in Conservation Agriculture. However, the term direct seeding can also be used for implements, which combine primary and secondary tillage and seeding in one machine/tractor operation like the rotary till drills.

Organic farming: Although it is based on natural processes, Conservation Agriculture is not a synonym of organic farming. CA does not prohibit the use of

39

chemical inputs. For example, herbicides are important component of Conservation Agriculture, particularly in the transition phase. However, in view of the importance of soil life, farm chemicals, including fertilizer, are carefully applied and over the years, quantities applied tend to decline. In some cases, organic farming can be practised within the CA framework.

Is CA compatible with IPM?

Conservation Agriculture is not only compatible but also actually works on IPM principles. CA, like IPM, enhances biological processes. It expands the IPM practices from crop and pest management to land husbandry. Without the use of IPM practices the build up of soil biota for the biological tillage would not be possible.

What is the role of Animal Husbandry in CA?

By recycling of nutrients, livestock production can be fully integrated into conservation agriculture. This reduces the environmental problems caused by concentrated intensive livestock production. Integration of livestock into agricultural production enables the farmer to introduce forage crops into the crop rotation thereby reducing pest problems. Forage crops can often be used as dual-purpose fodder and soil cover crops. However, in arid areas having low biomass production, the conflict between use of organic matter to feed the animals or to cover the soil is still to be resolved.

What are the downsides of CA?

During the transition phase, CA may require application of herbicides in case of heavy weed infestation and certain soil borne pests or pathogens might create new problems due to the change in biological equilibrium. Once the CA environment stabilizes, it tends to be more sustainable than conventional agriculture.

Benefits of CA

Conservation Agriculture attracts different people for different reasons.

Farmers

·Reduction in labour, time, farm power and thereby the production cost

·Longer lifetime and less repair of tractors due to fewer passes and lower fuel consumption

·More stable yields, particularly in dry years

·Better trafficability in the field

40

·Gradually increasing yields with decreasing inputs

·Increased profit, in some cases from the beginning, in all cases after a few years.

Communities/Environment/Watershed

·More constant water flows in rivers, re-emergence of dried wells

·Cleaner water due to less erosion

·Less flooding due to increased water infiltration rate

·Less impact of extreme climatic situations (hurricanes, drought etc.)

·Lower cost for road and waterway maintenance

·Better food security

At global level

·Carbon sequestration (greenhouse effect): the global potential of CA in carbon sequestration could equal the human made increase in CO in the 2

atmosphere.

·Less leaching of soil nutrients or chemicals into the ground water

·Less pollution of the water

·Practically no erosion (erosion is less than soil build up)

·Recharge of aquifers through better infiltration

·Lower fuel consumption for agriculture

What are the issues?

Despite its advantages, CA has spread relatively slowly for a number of reasons. Firstly, there is greater pressure to adopt in tropical, rather than temperate climates. Over the past 20 years the establishment of local knowledge base has ensured its spread. Converting to Conservation Agriculture needs higher management skills, the first years might be very difficult and might need moral support and perhaps even financial support to invest into new machinery like zero-tillage planters. As it requires a complete change of understanding, the scientific and technical sectors must focus on CA as the necessary technologies are often unavailable.

41

Is Conservation Agriculture real?

CA is being practised on more than 100 million ha, mostly in South and North America and its adoption is also growing exponentially on small to large farms in Europe as well as Asia.

New Machines for CA

The Double disc coulters and Punch planter/Star wheel are the machines being used in South and North America as well as in Europe, where large tractors and heavy machines are being used. The performance of smaller versions of these machines was not satisfactory in Asia. In India, two machines namely Turbo Happy seeder and Rotary Disk Drill (RDD) are developed/ improvised at PAU Ludhiana and DWR Karnal, respectively for seeding into surface retained residues after combine harvesting. Both these machines are based on the rotary till mechanism.

Conclusions

The conservation agriculture helps reduce or rather reverse the natural resource degradation by improving soil health and reducing ground water and environmental pollution. The soil moisture conservation and soil temperature moderation can help to a large extent in overcoming the adverse effects of climate change.

References:

Ballard CL, AL Scopel, RA Sánchez and SR Radosevich. 1992. Photomorphogenic processes in the agricultural environment. Photochemistry and Photobiology 56, 777-788.

Chhokar RS, S Singh, RK Sharma and M Singh. 2009. Influence of straw management on Phalaris minor control. Indian J. Weed Sci. 41: 150-156.

Crutchfield DA, GA Wicks and OC Burnside. 1986. Effect of winter wheat straw mulch level on weed control. Weed Science 34, 110-114.

Inderjit and Keating K.I. 1999. Allelopathy: Principles, procedures, processes, and promises for biological control. Advances in Agronomy 67, 141-231.

Jat, ML, SS Pal, AVM Subba Rao, Kuldeep Sirohi, SK Sharma and Raj K Gupta. 2004. Laser land levelling – the precursor technology for resource conservation in irrigated ecosystem of India. Abstracts. National conference on, “Conservation Agriculture: Conserving resources- enhancing productivity” September 22-23, 2004, New Delhi. Pp 9-10.

42

Nayar VK and MS Gill. 1994. Water management constraints in rice-wheat rotations in India. Pp 328-338 in 'Wheat in heat stressed environments: irrigated, dry areas and rice-wheat farming system' ed. by Saunders D.A., Hattel G.P., CIMMYT, Mexico DF.

Sharma RK, RS Chhokar, ML Jat, Samar Singh, B Mishra and RK Gupta. 2008. Direct drilling of wheat into rice residues: experiences in Haryana and Western Uttar Pradesh. In “Permanent Bed and rice-residue management for rice-wheat systems in the Indo-Gangetic Plain” (eds: E Humphreys and CH Roth). ACIAR Proceedings No. 127. Pp 147-158.

Unger PW. 1991. Organic matter, nutrient and pH distribution in no- and conventional- tillage semiarid soils. Agronomy Journal 83,186-189.

Yadav RL. 1998. Factor productivity trends in a rice-wheat cropping system under long-term use of chemical fertilisers. Experimental Agriculture 34,1-18.

43

Production Technology of Ginger under Changing Climate

H Dev Sharma and Vipin Sharma

Department of Vegetable ScienceDr YS Parmar University of Horticulture & Forestry, Nauni, Solan-173 230 HP

Ginger (Zingiber officinale Roscoe), a herbaceous perennial plant 30-100 cm tall having the underground rhizome that is cultivated as an annual, belongs to the family Zingiberaceae is an important cash crop and one of the principal spice crop all over the country and world. It is a crop with very rare flowering (0.5-67%) having yellow colour with dark purplish spots and in some cases do not flower at all and natural seed set has not been reported so far. It is native of South East Asia and originated in Indo-China region. India is the largest producer with more than 50% of the world production and exporter of ginger besides domestic consumption. China,Jamaica, Nigeria, Taiwan, Syria and Leone are other major suppliers of ginger in the global market. The USA, UK, Saudi Arabia, Canada, Japan and Singapore are the major importing countries. In India it is grown in an area of 149,100 ha with a production of 702,000 MT mainly in the states like Kerala, NE States, Sikkim, HP, WB, Odisha, TN, Karnataka, AP and Maharashtra. The crop occupies maximum area and production in Kerala while maximum productivity in Meghalaya. Kerala contributes maximum dry ginger i.e. sounth which is marketed internationally under the trade name “Cochin ginger”. However, India enjoys from the times immemorial a unique position in the production and export of ginger but the countries like Jamaica, Syria, Leone and China have throne a greater challenge to the Indian dried ginger in the international market. In HP, the ginger is grown in an area of 3,495 ha with a

thproduction of 50,034 MT. It is a cash crop of mid and low hills and more than 3/4 of the area and production is mainly from District Sirmaur. The other ginger growing areas are Solan, Bilaspur and Shimla and about 90% of ginger produced in the state is exported as fresh to the adjoining states like Punjab, Haryana, Delhi, UP and Chandigarh and generate a good income to the farmers of the state. Ginger of commerce is the dried rhizome. It is marketed in different forms such as raw ginger, bleached dry ginger, ginger powder, ginger oil, ginger oleoresin, ginger ale, ginger candy, ginger beer, brined ginger, ginger wine, ginger squash, ginger flakes etc. It is useful in gastric, cold and cough.

India is gifted with heterogeneous landforms and variety of climatic conditions such as the lofty mountains, the raverine deltas, high altitude forests, peninsular plateaus, variety of geological formations endowed with temperature varying from arctic cold to equatorial hot and rainfall from extreme aridity with a few

cm (<10 cm) to pre humid with world's maximum rainfall (1120 cm) of several hundred centimeter. This provides macro relief of high plateau, open valleys, rolling upland, plains, swampy low lands and barren deserts. These varying environmental situations in the country have resulted in a greater variety of soils.

Climatic requirements: Ginger is cultivated in almost all states in India. It can be grown in more diverse conditions than most other spices. Ginger requires tropical, subtropical, humid climate for its commercial production. It is grown successfully at sea level to 1500 m amsl and the optimum elevation is 300-900 m in hilly areas where the climatic conditions are different than plains especially in terms of rainfall and temperature. It can be grown both under rain fed and irrigated conditions. A well distributed annual rainfall of 1500-3000 mm during growing season and dry spells before land preparation and harvesting is required for good growth and yield of the

o ocrop. The favorable temperature range is 19-28 C, temperature lower than 13 C o

induces dormancy, higher than 32 C can cause sunburns and poor relative humidity o

is also unfavourable The optimum soil temperature for sprouting is 25-26 C and for ogrowth 27.5 C at increased day length (10-16 hours) vegetative growth is enhanced

while it is inhibited and rhizome swelling promoted as the day length decreased (16-10 hours). The foliage and rhizomes are also destroyed by frost resulting in poor storability. Cold climate during its resting period does not affect the crop. It thrives well under partial shade hence can be grown as an intercrop.

Impact of climate change: Climate change is one of the important alerts for present era. Several recent studies indicated that annual rainfall and diurnal temperature is in declining trend while maximum and minimum temperature is in warming trend. Piyasiri et at (2004) stated that in Sri Lanka, the reduction of mean annual rainfall during 1986-2001 has raised to 9% as compared to the period 1932-85. Ginger requires a warm and humid climate and a heavy rainfall. Peter et al. (2005) mentioned that "environment being a major factor influencing productivity in ginger, demarcating areas having ideal soil and climatic factors is important to achieve high productivity". North-Eastern states naturally have some good varieties and their climatic suitability is also good leading to high production. But in states like TN and Gujarat, the climate is only marginally suitable and the area under cultivation is low. However, the production of ginger in these two states are apparently due to the use of modern technology. Odisha, Karnataka, MP and WB which are environmentally suitable should give importance to varieties having high yield and quality with use of modern techniques of ginger cultivation to improve the productivity. Lanel and Jarvis (2006) also projected the future data for 2055 and predicted that climate change will cause shifts in areas suitable for cultivation of a wide range of crops.

.

45

Parthasarathy, et al (2008) used the Geographic information system (GIS) to assess land suitability of ginger for current and potential regions in changing scenario of Indian climate and reported that the area, production and productivity of ginger have consistently shown an increasing trend during the last 3 decades. Increase in area is not always in proportion with the increase in production. Thirty years area and production curves of the important ginger growing states were compared with the Eco-crop suitability model which indicated that suitability has direct impact on production. Odisha, WB, Mizoram and Kerala are very highly suitable while North-Western states like Gujarat, Rajasthan, UP and MP are marginally suitable or unsuitable. North-Eastern and South-Western states are ideally highly suitable for ginger cultivation. Future prediction of Eco-crop model

0shows, if the temperature increase by 1.5-2.0 C, the suitability of Odisha and WB will reduce drastically from high suitability to marginally suitable, indicating the effect of climate change. As a result of which the overall suitable areas will increase, but most affected by loss of area will generally be regions that are already struggling from the impacts of irregular and extreme climatic events. There are many other factors which affect the production of a crop but here we are mainly concerned with the suitability of climate as an important factor on the crop.

Soil requirements: Ginger can be grown in all types of soils but the ideal one is sandy loam soil, light, loose, friable, well drained and at least 30 cm depth and new soils rich in humus are the best having 5.5-8.5 pH however, rhizome growth is better in slightly acidic soils (pH 6.0-6.5) than neutral soils. Mostly grown as rain fed, though irrigation is useful. However, it is very sensitive to water logging, frost and salinity. It is tolerant to drought and wind. Stiff clays and course sandy soils are unsuitable and can be improved by adding sufficient organic manure.

Site selection: The site should be flat with sufficient slope to avoid water stagnation, well drained, rich in humus, organic matter and free from diseases and insect pests. Partial shade conditions are preferred. Ginger crop should not be grown on the same field for at least three years to avoid infection of rhizome disease a serious problem in ginger industry.

Varieties: In ginger different materials known by the name of the locality is mostly grown e.g. Kuruppampadi, Thodophuzha, Wynad, Wynad Local, Emad, Chemad, Dholka, Maran, Tura, Himachali, etc. Similarly exotic varieties like Rio-de-Janerio, Jamaica, China etc. Differential performance of these varieties in different locations is observed. Recently seven cultivars released by AICRP on Spices Varda, Mahima and Rajetha by IISR, Calicut; Surubhi, Suruchi and Suprabha by HARS, Pottangi and Himgiri by UHF Solan, mostly for local state cultivation.

46

Planting time: It is planted in the month of April in all the ginger growing states of the country, delay in sowing decreases the yield, the early sowing makes sufficient growth that withstands rains and grows rapidly when there are heavy rains during July-August. In West coast of India, the best time for planting ginger is during the first fortnight of May with the receipt of pre-monsoons, first week of April has been found to be the best time of planting under Kerala condition registering 200% increase in yield as compared to planting first week of June. In eastern India planting is done in March. Under irrigated conditions, it can be planted well in advance during mid February or early March. Sowing in HP is according to the altitude i.e. April-May in mid and high hills and May-June in low hills. Burning of surface soil and early planting with the receipt of good summer showers consistently gives higher yield and reduces the disease incidence.

Land preparation: The land is ploughed 3-4 times or dug to bring the soil to a fine tilth. Compost or well rotten FYM should be applied at the time of field preparation and mixed thoroughly. Beds of convenient size about 3 m long, 1 m wide and 15 cm raised are prepared with channels of 30-45 cm to avoid stagnation of water. The alignment of the channels should be in such a way that during rainy season these should act as drains for excess water and before and after rainy season as irrigation channels. This space will also help in moving about, while hoeing, weeding, mulching, top dressing and rouging and inspection of the crop. In plains, deep drains should be provided to drain-off excess water during rainy season.

Propagation: Ginger is universally propagated from cuttings of seed rhizomes known as bits. Carefully preserved seed rhizomes are broken or cut into small pieces i.e. bits of 2.5-5.0 cm long weighing 20-30 g each having at least one or two good buds/eyes or growing points. While preparing the seed bits, the hands or the knives used should be washed with detergent powder and the knives be sterilized after some interval to avoid transmission of disease inoculums to the healthy rhizomes of seed ginger. Tissue culture technique has also been developed to produce healthy ginger plants/ plantlets but it has not been exploited commercially because of higher cost involvement and sophisticated equipment and machinery.

Seed rate: The ginger seed is very costly input and involves about 50 % of the total cost of production. Seed rate vary with the size or weight of the seed bits and may be 12.5-25.0 q/ha. Bit size may be 15-150 g or 3-10 cm in length or with 2-8 eyes. There is direct correlation of seed bit size with rhizome yield. Seed bits of 20-25 g having 2-3 eyes are generally recommended. The use of high seed rate may be advantageous if to compensate the high seed cost involved at the time of sowing the farmers can recover the healthy mother rhizomes.

Seed treatment: The seed material used must be healthy. Treat the seed before sowing with a mixture of Dithane M-45 (0.25%) + Bavistin (0.10%) +

47

Chloropyriphos (0.2%) for 60 minutes and dry in shade for 24 hrs as a safeguard against soft rot and to induce early sprouting. Rhizomes for seed are also treated in

ohot water at 48 C for 20 minutes before planting. Soaking seed rhizomes in water for 24 hours, 10 days prior to planting results in good sprouting.

Spacing: Ginger can be sown on ridges or furrows or flat beds, however, flat sowing on raised beds is preferred. Depending on the seed rhizome size and weight, agro-ecological situation etc. the spacing ranges 15-20 x 20-30 cm between plants and rows. Generally, closer spacing produces the higher yields. Under AICRP on Spices, general recommendation of spacing for whole of the country is 20 x 25 cm. Seed bit is placed 3-5 cm deep in the soil.

Manures and fertilizers: Ginger is exhaustive and long duration crop thus requires reasonable amount of manure and fertilizers. Recommendations vary with soil type, initial fertility levels, locality and variety. Generally, 25-30 t/ha FYM is recommended. The heat generated by the manure is helpful in proper germination of seed rhizomes. The amount of inorganic fertilizers depends on the fertility of soil and organic manure used. Generally, it ranges between 100-120 Kg of N, 75-80 kg P and 100-120 kg K per hectare. Different fertilizer recommendations e.g. N 30-l00 kg/ha, P O 20-100 kg/ha and K O 50-200 kg/ha has been reported by different workers. The 2 5 2

general recommendation given by the AICRP on Spices is 100, 50, 50 kg NPK/ha. The FYM is applied either by broadcasting or by putting in the hole over the seed and cover with soil. Full dose of P and K applied at the time of field preparation, however, K can also be given in two splits first half at the time of field preparation and second half 90 days after sowing. N is applied in three splits first 1/3 at the time of field preparation, second 1/3 one month after germination and third 1/3 one month after second split. The beds are to be earthed up after each top dressing with the fertilizers. In ginger the total period of growth is categorized into three phases: active vegetative growth (90-128 days after planting; slow vegetative growth (129-180 days after planting) and phase approaching senescence (181 days onwards). Marked uptake of NPK is during active growth. Use of micronutrients have also been attempted and Zn and B found useful. B was also reported to reduce soft rot incidence. Application of neem cake @ 2 t/ha at the time of planting helps in reducing the incidence of rhizome rot of ginger and increases the yield. The ginger growers have observed that the rhizomes produced with heavy doses of nitrogenous fertilizers have a lower storage capability because of the reason that the over dose of the nitrogenous fertilizers helps in inducing more tenderness, delicacy leading to proneness to rhizome rot disease, insects like maggots and nematode infection both in field and storage.

Mulching: Mulching of ginger is essential as it enhances sprouting, increase infiltration and organic matter, conserves soil moisture, maintains optimum

48

temperature and prevents weeds, evaporation and washing of soil due to heavy rains. In addition, it enhances microbial activity and improves soil fertility. Different mulch materials are used keeping in view the easy availability and economic feasibility. Preferably locally available material like green or dry grass/ leaves, paddy straw, cane trash, banana leaves, mango leaves, oak leaves, pine needles, FYM etc. can be used. One or two applications can be given; one at the time of sowing and the second 6-8 weeks after sowing. A range of 5-30 t/ha has been tried by different workers and generally 20-25 t/ha is recommended. The first mulching is done at the time of planting or just after planting in 4-5 cm thick uniform layer with green leaves @ 10-12 t/ha or dry leaves @ 5-6 t/ha. Mulching is to be repeated @ 5 and 2.5 t/ha green and dry leaves, respectively, at 40 and 90 days after planting, immediately after weeding, hoeing, earthing up and application of fertilizers. An increase in yield with mulching may be 50-100%. Under low shade mulching may be reduced without affecting the yield.

Inter-cropping and cropping systems: Ginger is a long duration crop and takes 8-9 months. The field remains occupied for longer duration. Other crops are planted to get maximum returns per unit area. Ginger can be planted in young citrus and forestplantations/orchards up to 5-6 years of mango, litchi, citrus, apple, peach, pear, plum, coconut, coffee, areca nut, etc. These also provide shade as it prefers partial shade. Annual crops like maize, chilli, okra, Colocassia, amaranths, gram, etc are also found to be the best companion crops. Avoid solanaceous crops especially tomato and brinjal as these are highly susceptible to root knot nematodes. In this way, more income is obtained and in case of natural hazards like cloud-burst, hail-storms, unusual rains or snowfall etc. if the fruit crop is damaged, ginger crop is safe and vice-versa. Sometimes when the ginger crop is wiped-off because of the appearance of rhizome rot disease or maggots or nematodes, growers will earn from the fruit/ forest produce. The ginger crop is not cultivated on the same piece of land for at least 2-3 years and rotated with other crops like paddy etc. depending on the severity of the diseases-rhizome rot, ginger yellow and pests-maggots and nematodes. Commonly rotated with turmeric, onion, garlic, chillies, other vegetables and maize and groundnut in irrigated conditions. In NE States, ginger is grown under jhoom/ shifting cultivation system, where ginger rhizomes are planted on a virgin land after preparation and shifting to the new site to make use of the forest land rich in organic matter.

Shade requirement: Crop when grown in open condition there is lower leaf number, leaf area index, chlorophyll content, growth rate and dry matter production, bulking rate and green ginger yield when compared to 25 to 50% shade levels. Under 75% shade vegetative growth and rhizome yield are reduced in comparison to 25-50%. Cropunder 25% shade performed better. Maize growing in alternate inter row space

49

has been found beneficial in comparison to sole cropping in terms of tillering and yield. Shade tolerance varies from cultivar to cultivar.

Irrigation: The ginger crop grown under irrigated conditions is watered immediately after sowing as it helps in early sprouting. Usually ginger crop needs frequent irrigation where the soil has less water retention capacity. During rainy season there is no need for irrigation. In hilly areas where ginger is grown as rain fed crop if the rains are well distributed 2-3 irrigations are sufficient and given at fortnightly interval or as and when required. The total water requirement of ginger crop ranges between 1320-1520 mm during the complete crop cycle. The rhizomes from rain fed crop has more fibre than irrigated one raised under lower elevations. Studies have shown that sprouting, rhizome initiation (90 DAP) and rhizome development (135 DAP) are critical stages of irrigation.

Drainage: The excess water in the field whether it comes from over irrigation or from natural source or rain/ snow water accumulation need to be immediately removed from the field to ensure normal crop growth, as poorly drained soils not only harm the ginger crop directly but create various problems in scheduling the mechanical farm operations, invite and promote the development of diseases and pests.

Earthing-up: It helps in pulverizing the soil leading to proper aeration, suppresses the weed growth and covers the growing rhizomes for better enlargement; besides, provide mechanical support to the growing stem. The main aim of earthing-up is to make the plant base strong/ stable to avoid lodging of the plants even if there happen to be strong wind. At least two earthing-ups one after 45- 90 days and another after 135 days after planting should be done.

Weed management: Ginger is very conducive to weed growth except when mulched and adequate weed control is essential during stages of crop growth. The field should be kept neat and clean free from weeds. Weeding is done just before fertilizer application and mulching, 2-3 weedings are required depending on the intensity of weed growth, the first is done just before the first mulching and repeated at monthly interval. While doing hoeing every care should be taken that the rhizomes are not disturbed, injured or exposed. Weeding is, however, done manually. The use of chemical weedicides like Simazine @ 1.5 L/ha or Basalin @ 2.0 L/ha or Attrazine applied immediately after planting as pre-emergence have been reported effective in controlling most of the weeds.

Harvesting and yield: The stage of harvesting depends upon the purpose for which crop is grown, price trend, variety and agro-climatic conditions. For tender rhizome sold as green ginger for preserve or making pickle, murabba, ginger candy, soft

th drinks an immature crop is harvested from 5 month after planting (MAP) when there

50

is minimum of crude fiber, maximum of volatile oil, oleoresin and starch. For making dry ginger, maturity indices are: shriveling, yellowing, withering of leaves, accompanied by drying and lodging of aerial stems i.e. 8-9 MAP, gives more fibrous and pungent rhizomes. Highest dry ginger recovery was recorded at 270 days after planting (DAP) and maximum percent of oil, oleoresin and fibre was recorded at 165 DAP. Between 5.5-6 MAP fiber per day increases @0.12%. As the physiological age of rhizome increases, so does the diameter and strength of fibre. Fibre development is rapid between 180-270 DAP. Fibrous ginger is not acceptable to confectioners due to its reduced palatability. Oleoresin and oil contents rise up to 165 to 180 DAP beyond which there is decline. For seed ginger, rhizomes are left in field as such for 3-4 weeks more when the skin of rhizome ripens, thickens and become stiff i.e. fibrous with pungency and leaves and pseudo stem completely dry and fall down. In hills harvesting must be done before appearance of frost. The clumps are lifted carefully with a spade or digging fork or on a large scale the field is ploughed and the rhizomes are collected. The rhizomes are then separated from the dried up leaves, roots and adhering soil and washed thoroughly in water to remove the soil and sun dried for a day.

The yield of ginger varies with variety, care and management of crop and agro-climatic conditions of locality, where it is grown. Maximum yield to the tune of 30-40 t/ha has been reported, however, 12-15 t/ha is generally obtained. The yield of dry ginger is 15-25 % of the fresh ginger depending upon the variety and locality.

Storage of rhizome: Rhizome is highly perishable and susceptible to soil borne fungi and insects, thus needs to be stored appropriately. Poor storage causes rotting, dehydration and sprouting. Ginger may be stored in cool and dry environment, to keep the material for the next season sowing and also if price is not adequate. Fully mature and disease free rhizomes are stored. Conventionally the storage is done above or below ground. In above ground, the rhizomes are kept in heap on sand layer or paddy husk and covered with dry leaves and plastered with cow dung. In below ground, pits of size l x l x l m or as per requirement are made under shade/ shed. The walls of this pit are plastered with cow dung with a layer of sand at the base. Healthy and disease free rhizomes treated in solution of Dithane M-45 + Bavistin + Chloropyriphos are placed loosely. Filling is done up to 10-15 cm below from the top. This top is covered with dry grass. The pit is closed with the help of wooden plank. Plaster the space between the planks with soil or cow dung. Keep or place a perforated PVC pipe of 2 inches diameter in the centre of the pit for removal of gases. The material is stored for 3-4 months and taken out from the pits at least 20-25 days before sowing. Controlled storage is not followed in our country only report from Hawaii indicates that quality of ginger remains stable for 28 weeks if stored at 12-13°C and 65 % RH.

51

a) For green ginger: Green rhizomes harvested after 8-12 months are stored at 12-o

18 C and 60-80% RH. Various fungi, bacteria, nematode and insects have been found to be associated with ginger rhizome causing rot and decay resulting in heavy post harvest loss. Oil and oleoresin yield decrease with storage. The refrigerated storage up to 4 weeks has no adverse effect on quality but storage at room temperature may generate the problems like rhizome rot, sprouting, rooting and shriveling of rhizomes. Fresh ginger can be stored in 200 gauge thick poly-bags of 35 x 25 cm with 125 punch holes each with 4 mm diameter. The ginger is cleaned and dried and sealed with stapler or rubber band. Bags should be kept in cool dry places with air circulation and be inspected at fortnightly intervals. After around 4 months, the weight of 1 kg bag will remain around 700 g.

b) For seed ginger: Seed ginger has to be stored for about 3-4 months from harvesting to its further planting. For seed purpose, fully mature, big, plump rhizomes, free from diseases are selected after harvesting. The rhizomes are treated before storage. A drum of 200 liters capacity is filled with 100 liters of water. Few liters of water is taken in a bucket added with 250 g Dithane M-45+100 g Bavistin+200 ml of Chloropyriphos and mixed thoroughly. Then 80 kg rhizomes are steeped in the drum for 30 minutes. Solution is drained off and rhizomes are dried under shade and stored. Rhizomes are best stored by pit method.

References

Arya, P.S. 2001. Ginger Production Technology, Kalyani Publishers, New Delhi.

Lane1, A. and Jarvis, A. 2006. Changes in Climate will modify the Geography of Crop Suitability: Agricultural Biodiversity can help with Adaptation. An Open Access Journal published by ICRISAT http:// Journal Special Project/ sp2.pdf

Peter, K.V.; Nybe E.V. and Kurien A. 2005. Yield gaps and constraints in ginger. In: Ravindran P.N. and Nirmal Babu K. (Eds.) Ginger The genus Zingibel 527-532.

Tiwari R.S., Agarwal A. 2004. Production technology of spices. International book distributing co. Lucknow India.

Utpala Parthasarathy, K. Jayarajan, A.K. Johny and V.A. Parthasarathy (2008). Identification of suitable areas and effect of climate change on ginger - a GIS study. Journal of Spices and Aromatic Crops 17 (2) : 61-68

www.icrisat.org

52

Production Technology of Turmeric under Changing Climate

H Dev Sharma and Vipin Sharma

Department of Vegetable ScienceDr YS Parmar University of Horticulture & Forestry, Nauni, Solan-173 230 HP

Turmeric (Curcuma longa L.) an erect herbaceous perennial 60-100 cm tall having rhizome with fingers is one of the important spice crops in India belonging to the family Zingiberaceae and plays a vital role in the national economy. It has been originated from Southern Asia, probably India in the slopes of hills in the tropical forests of West Coast of South India (Stahl, 1980). About 18 species occur in India of which a few are important spice plants. C. longa is cultivated in large area and C. aromatica popularly known as Cochin turmeric or Kasturi manjal, used for the preparation of kum-kum is also grown in some parts. C. amada the flesh of which has the taste and flavor of raw mango and therefore it is known as mango ginger. Turmeric is very much identified with human civilization, religion, customs and it finds use both in developed and underdeveloped countries. It is grown for underground stem called as rhizomes, which are used to impart flavour and colour to foodstuffs after clearing, drying, polishing and powdering. It is a principal ingredient in curry powder. Turmeric oleoresin is used in brine pickles and to some extent in non-alcoholic beverages, gelatins, butter and cheese, etc. The colour curcumin extracted from turmeric is used as a colorant. Turmeric is also used as a dye in textile industry. It is used in the preparation of medicinal oils, ointments and poultice. It is stomachic, carminative, tonic, blood purifier and an antiseptic. It is also used in cosmetics. The aqueous extracts have bio-pesticidal properties.

It is grown on a large scale in India, China and East Indies. About 18 states in India cultivate turmeric; however, turmeric cultivation is largely confined to South and Eastern India. AP followed by Odisha, TN and Maharashtra states in India constitutes the lion's share in India's turmeric production. It is grown to a small extent in the lower and mid-hill altitudes in Meghalaya and HP. India has a prime position in the world and is largest producer, consumer and exporter of turmeric and accounts for more than 50 % of the world trade. The area under turmeric in India is 195,100 ha with an annual production of 992,900 m t and productivity 5.1 t/ ha. Out of the total turmeric produced in India 90% is consumed locally and remaining 10% is exported to various countries like USA, UK, Middle East, Japan, Singapore, Malaysia, South Africa, Australia and other countries. One of the most important problems facing the turmeric crop is its duration of 7-9 months. Therefore, the main objective of breeding work on turmeric is evolving short duration varieties with high yield, oil and curcumin content. In HP, turmeric has not attained significant status among spice crops probably due to poor yield and being a long duration crop, however, some growers especially in lower hills have started showing interest in the crop and the

area is steadily increasing as the crop can be successfully planted under rain fed conditions under minimal care and attention. Moreover, increasing monkey menace and engagement of farmers in other occupations offer better opportunities for increasing acreage under this crop in the state.

India is gifted with heterogeneous landforms and variety of climatic conditions such as the lofty mountains, the raverine deltas, high altitude forests, peninsular plateaus, variety of geological formations endowed with temperature varying from arctic cold to equatorial hot and rainfall from extreme aridity with a few cm (<10 cm) to pre humid with world's maximum rainfall (1120 cm) of several hundred centimeter. This provides macro relief of high plateau, open valleys, rolling upland, plains, swampy low lands and barren deserts. These varying environmental situations in the country have resulted in a greater variety of soils.

Climatic requirements: The crop requires a hot and moist climate with a liberal water supply. Turmeric is mostly a tropical plant cultivated throughout India in tropical and sub-tropical humid climate. In most valleys and hill sides of peninsular India both in Eastern and Western Ghats, wild forms of turmeric are found. In the delicate tracts and interior regions of South India and the North Punjab, from sea level up to an altitude of 1500 m with an optimum range of 450-900 m turmeric is cultivated. It tolerates an annual rainfall of 640 to 4290 mm. Moderate rainfalls of 1500 mm at sowing, fairly heavy and well distributed rain during growing period and dry weather about one month before harvest are much suitable. The temperature

0range of 18.2-27.4 C is optimum. The crop is raised rain fed where rainfall is bimodal and with irrigation in plains where rainfall is unimodal and low. In general, mean minimum air temperature, total rainfall, and number of rainy days, mean minimum relative humidity showed positive and mean evaporation, mean sunshine hours, mean solar radiation and mean maximum air temperature showed negative relationship with yield. Turmeric cultivated in the hills is reported to be a better quality than that raised in the plains. It is stated that the same variety when grown in the plains and on the hills shows distinct differences in quality and yield.

Climate change is one of the important alerts for present era. Several recent studies indicated that annual rainfall and diurnal temperature is in declining trend while maximum and minimum temperature is in warming trend. Piyasiri et al (2004) stated that in Sri Lanka, the reduction of mean annual rainfall during 1986-2001 has raised to 9% as compared to the period 1932-85. Lanel and Jarvis (2006) also projected the future data for 2055 and predicted that climate change will cause shifts in areas suitable for cultivation of a wide range of crops.

Soil requirements: Turmeric can be grown on various soils but thrives best in well drained, friable, rich sandy or clay loam soils having pH range of 4.3 to 7.5. Crop stands neither water logging nor alkalinity. Loamy soils are best suited for the development of rhizomes. It requires a highly fertile soil and areas having drainage facilities are also suitable. The soils should be devoid of stones or gravels or too coarse fractions.

54

Varieties: A number of cultivars are available in the country and are known mostly by the name of locality where they are cultivated. Some of the popular cultivars are- Duggirala, Cuddapah, Tekurpeta, Sugandham, Amalapuram, Erode local, Alleppey, Wynadan, Moovattupuzha, Rajapuri, and Lakadong. The improved varieties of turmeric are- Suvarna, Suguna, Sudarsana, Prabha, Prathibha, Krishna, Sugandham, Roma, Suroma, Ranga, Rasmi, Rajendra, Sonia, Alleppey, Supreme, Kedaram, Co-1, BSR-1 and BSR-2. Among the clonal selections Suguna, Sudarshana and Suvama yielding 25-35 t/ha and IISR Prabha with a curcumin content of 6.52% are important. Three categories of turmeric varieties viz. long duration types i.e. 9 months duration: Duggirala, Tekurpeta, Armoor and Mydukur,; medium duration types i.e. 8 months duration: Kothapet, Krishna, Kesari and short duration types i.e. 6-7 months duration: Amalapuram, Dindigram, Suguna, Sudarshan are available.

Planting time: The time of planting of turmeric varies with the cultivar as well as the agro climatic condition of the area. It is generally planted between mid-April and August. Studies conducted at Tamil Nadu revealed that turmeric planted at 1st June gave highest yield of 40 t/ha. In general yield decreased with late planting. Turmeric can be planted during April-May with the receipt of pre-monsoon showers. However, time of sowing for short duration varieties is second fortnight of May, for mid duration varieties first fortnight of June and for long duration varieties second fortnight of June to second fortnight of July.

Land preparation: The land is ploughed 3-4 times or dug to bring the soil to a fine tilth. Compost or well rotten FYM should be applied at the time of field preparation and mixed thoroughly. Beds of convenient size about 3 m long, 1 m wide and 15 cm raised are prepared with channels of 30-45 cm to avoid stagnation of water. The alignment of the channels should be in such a way that during rainy season these should act as drains for excess water and before and after rainy season as irrigation channels. This space will also help in moving about, while hoeing, weeding, mulching, top dressing and rouging and inspection of the crop. In plains, deep drains should be provided to drain-off excess water during rainy season.

Propagation: Turmeric is commonly propagated by rhizomes. Mother rhizomes as well as fingers are used as planting materials. Studies conducted to determine the most suitable planting material have revealed that generally mother rhizome is the most suitable planting material. Whole or split mother rhizomes are used for planting. Well developed healthy and disease free rhizomes are to be selected. Planting primary fingers has become a common practice in A.P., because they keep better in storage, more tolerant to wet soil and involve low seed rate. The conventional method of propagation has a number of drawbacks, viz. 2 months dormancy period of rhizomes, only 5-6 plants can be obtained from each rhizome; and a sizeable percentage of the produce has to be put aside as seed material. To overcome these problems tissue culture technique was tried for propagation of some high yielding cultivars- Duggirala, Tekurpeta, BSR-1 and Co-1 giving high success percentage.

55

Seed rate: Seed rate vary between 20-25 q/ha.The seed rhizome pieces of 30 g with 2 to 3 eyes are planted. Rhizomes are treated with 0.25% Dithane M-45 + 0.10%

0Bavestin for 30 minutes before sowing. Hot water treatment at 50 C for 30 minutes without affecting germination eradicates all fungi associated with turmeric seed rhizome.

Spacing: Seed rhizomes are planted in small pits made with a hand hoe in the beds in rows with spacing of 30 x 20 cm and covered with soil or dry powdered cattle manure. Germination starts in 10-20 days and will be over by 60 days.

Manures and fertilizers: Farmyard manure or compost @ 30-40 t/ha is applied by broadcasting and ploughed at the time of preparation of land or as basal dressing by spreading over the beds or in to the pits at the time of planting. Zinc @ 5 kg/ha may be applied at the time of planting and organic manures like oil cakes can also be applied @ 2 t/ha and in such case, the dosage of FYM can be reduced. In Simla hills, due to scarcity of FYM in the hilly regions, a fertilizer requirement of 150:50:50 kg/ha NPK proved to be the best and significantly increased the yield of the crop. Integrated application of compost @ 2.5 t/ha combined with FYM, biofertilizer (Azospirillum) and half of recommended dose of NPK is also recommended. Fertilizers @ 60 kg N, 50 kg P O and 120 kg K O per hectare are to be applied in split doses as given below.2 5 2

Schedule N P O K O Compost/cow dung2 5 2

Basal application - 0 kg - 30-40 t

After 45 days 0 kg - 60 kg -

After 90 days 30 kg - 60 kg -

Mulching: Mulching is essential as it enhances sprouting, increase infiltration and organic matter, conserves soil moisture, maintains optimum temperature and prevents weeds, evaporation and washing of soil due to heavy rains. In addition, it enhances microbial activity and improves soil fertility. Different mulch materials are used keeping in view the easy availability and economic feasibility. Preferably locally available material like green or dry grass/ leaves, paddy straw, cane trash, banana leaves, mango leaves, oak leaves, pine needles, FYM etc. can be used. Generally, 20-25 t/ha is recommended. The first mulching is done at the time of planting or just after planting in 4-5 cm thick uniform layer with green leaves @ 10-12 t/ha or dry leaves @ 5-6 t/ha. Mulching is to be repeated @ 5 and 2.5 t/ha green and dry leaves, respectively, at 90 days after planting, immediately after weeding, hoeing, earthing up and application of fertilizers.

Inter-cropping and cropping systems: Turmeric is a long duration crop and takes 8-9 months. The field remains occupied for longer duration. Other crops are planted to get maximum returns per unit area. It can be grown as an intercrop with many other crops because it comes up well in partial shade conditions, although thick shade affects the yield adversely. Therefore, it is recommended as an intercrop in coconut and areca nut gardens. Turmeric can be grown as an inter crop with chillies,

56

colocasia, onion, brinjal, arhar or sunhemp and cereals like maize, ragi, etc. In this way, more income is obtained and risk of loss in case of natural hazards is reduced. It is commonly rotated with onion, garlic, chillies, other vegetables and maize and groundnut in irrigated conditions.

Irrigation: A good soaking irrigation is given immediately after sowing. Thereafter, irrigate at weekly interval. The number of irrigations may be varied with the soil types. 15 to 20 irrigations are given for clayey soils and about 40 for sandy loams. During the period of rhizome development and maturity, frequent irrigations are necessary. In organic system quality of irrigation water is important, sewage water, waste water from industry is not allowed.

Drainage: The excess water in the field whether it comes from over irrigation or from natural source or rain/ snow water accumulation need to be immediately removed from the field to ensure normal crop growth, as poorly drained soils not only harm the turmeric crop directly but create various problems in scheduling the mechanical farm operations, invite and promote the development of diseases and pests.

Earthing-up: It helps in pulverizing the soil leading to proper aeration, suppresses the weed growth and covers the growing rhizomes for better enlargement; besides, provide mechanical support to the growing stem. The main aim of earthing-up is to make the plant base strong/ stable to avoid lodging of the plants even if there happen to be strong wind. Usually practiced during 45-60 days after planting (DAP) 90-105 DAP, additional if required done on 120-135 DAP. This helps to form and enlarge rhizomes and also protect rhizome from insects.

Weed management: The growth of turmeric during initial phase is slow and weed management during this time is must. Mulching reduces the weed emergence and intercropping with quick growing crops also smothers the weeds. The field should be kept neat and clean free from weeds. Weed intensity vary with location and traditionally manual weeding is done three to four times, the first is done just before the first mulching and repeated at monthly interval. Weeding is generally done just before fertilizer application and mulching; while doing hoeing every care should be taken that the rhizomes are not disturbed, injured or exposed. The use of chemical weedicides like Simazine @ 1.5 L/ha or Basalin @ 2.0 L/ha or Attrazine applied immediately after planting as pre-emergence have been reported effective in controlling most of the weeds.

Harvesting and yield: Depending upon the varieties, the crop comes to harvest in 7-9 months. Main season of harvesting falls in January to April. Maturity indication is complete yellowing and drying up of plants. Above ground parts are cut close to the ground level. Field is irrigated 1-2 days in advance of harvesting the crop. Crop is harvested by ploughing or digging. Rhizomes are gathered by hand picking and cleaned. Rhizomes are washed. Mother rhizomes are separated from the fingers before they are cured. Indian average yield is 20-22 t/ha.

57

Storage of seed rhizomes: Turmeric may be stored in cool and dry environment, to keep the material for the next season sowing. Poor storage causes rotting, dehydration and sprouting. Fully mature and disease free rhizomes are stored. Conventionally the storage is done above or below ground. In above ground, mature, healthy rhizomes are heaped over a layer of 5-10 cm sand under shade of a tree or shed. These are covered with turmeric leaves. Then heaps are plastered with earth mixed with cow dung. The rhizomes are treated with Dithane M-45 @ 0.25% + Bavistin @ 0.10% solution for 30 minutes and shade dried before heaping. Remove rotten rhizomes at the end of storage period. Rhizomes for seed purpose are generally stored by heaping in well ventilated rooms and covered with turmeric leaves. In below ground, pits of size l x l x l m or as per requirement are made under shade/ shed. The walls of this pit are plastered with cow dung with a layer of sand at the base. Healthy and disease free rhizomes treated in solution of Dithane M-45 + Bavistin are placed loosely. Filling is done up to 10-15 cm below from the top. This top is covered with dry grass. The pit is closed with the help of wooden plank. Plaster the space between the planks with soil or cow dung. Keep or place a perforated PVC pipe of 2 inches diameter in the centre of the pit for removal of gases. The material is stored for 3-4 months and taken out from the pits at least 20-25 days before sowing. The seed rhizomes can also be stored in pits with saw dust and sand.

References:

Parthasarathy,V.A., Kandiannan, K. and Srinivasan, V. 2008. Organic Spices. New India Publishing Agency, Pitam Pura, New Delhi, India.

Shanmugavelu, K.G., Kumar, N. and Peter, K.V. 2002. Production Technology of spices and Plantation Crops. Agrobios, Jodhpur, India.

Tiwari R.S., Agarwal A. 2004. Production technology of spices. International book distributing co. Lucknow India.

58

Protected Cultivation of High Value Vegetable Crops

Manish Kumar

Department of Vegetable Science,Dr YS Parmar University of Horticulture & Forestry, Nauni, Solan HP 173 230

Vegetable growing is becoming an industry in the country because of its increasing demand and per capita requirement. The Indian scenario has changed tremendously during the last decade because of change in the life style and food habits. The people are becoming more aware to eat healthy foods. Vegetables are an important component of health food and provide nutritional and health security. The commercial production also derives the monitoring benefits to the growers. Hence it is pertinent to grow more vegetables with good quality and clean and green produce. This can be achieved by employing improved agro techniques of precision farming and greenhouse technology.

Protected cultivation, which in the past was considered only as a means of production only for affluent western countries having unfavorable environments, is now very much needed under Indian conditions to improve the productivity and quality of the vegetables to remain competitive in the global markets (Kohli et al., 2007). After the green revolution more emphasis has been laid on the quality along with quantity of the produce to meet the ever-growing food requirements. Both these demands can be met when the growing environment for the plant is suitably modified. The need to protect the crops and to sustain production even under unfavorable climates led to the development of protected cultivation. To increase quality of produce of high value cash crops having export potential, the only potential approach is perfection and promotion of Green House Technology.

The practice of protected cultivation of vegetable crops is also becoming popular in the hilly regions of the country, which offers a great scope for use of low cost naturally-ventilated polyhouses because of mild climate. Himachal Pradesh is also not an exception to this cultivation and most of the growers in the lower mid hills and mid hills are adopting this technology. The use of structures like solar green houses, walk-in-tunnels and soil trenches have already made a breakthrough in the popularization of this technology in dry and cold desserts of the country paving a way for attractive remuneration generation at the farmer's level.

Growing of crops under protection has many advantages but nowadays it is specifically gaining more importance for raising high value cash crops with off-seasonality and superior quality of the produce. Protected cultivation also enables vegetable growers to realize greater returns per unit of land and offer other benefits,

like early harvest, longer harvest duration, reduced leaching of fertilizers and eco-friendly management of pests, weeds and diseases (Kumar et al. 2007)

In India, in the present scenario of perpetual demand of vegetables and shrinking land holdings drastically, protected cultivation is the best alternative and drudgery-less approach for using land and other resources more efficiently (Sirohi and Bahera, 2000). Controlled environmental conditions are used for early raising of nurseries, off-season production of vegetables, there seed production and protecting the valuable germplasm (Mangal and Singh, 1993). Greenhouse is the most practical method of accomplishing the objectives of protected cultivation (Nagarajan et al., 2002). Tomato, Capsicum and cucumber are the most extensively grown vegetables under green houses and give higher returns (Chandra et el. 2000). Growing of cucumber using cost effective plastic greenhouses provides an alternative for raising crop in the period of scarcity in Himachal Pradesh. This also ensures to meet year round supply of fresh produce with more efficient resource utilization. (Sharma et al. 2009).

2India is having 74,809 km of cold desert area in states of Jammu & Kashmir and Himachal Pradesh. The region is characterized by high altitude sandy mountains, extremely low temperatures and short cropping season (May-September). It is difficult to grow anything here in winter. Different greenhouse structures viz. glasshouse, polyhouse, local mud polyhouse and trench (underground greenhouse) were evaluated for vegetable production at Field Research Laboratory, Leh (Singh, 1998).

For round the year production of vegetables, scientists of FRL-Leh have developed a new cost effective protected cultivation structures like Solar Greenhouses and under ground green house technology.

Major advantages of this technology

·Raising of vegetable nursery or transplants under protection.

·The potential of polyhouse production technology to meet the demand of producing good nutrition and healthy foods and quality vegetables free from pesticides can be fully exploited.

·Vegetable crops can be grown under adverse weather conditions round the year and off-season.

·The vegetables can be produced with higher productivity and uniform quality of produce than open field cultivation.

·Management and control of insect-pests, diseases and weeds is easier.

·There is efficient resource management.

60

·In the hilly terrains, the farmers generally have small land holdings and this technology provided a useful impetus to their farming livelihood by more productivity and more money from less land.

Future needs

Polyhouse vegetable production in the country is still in infancy and for its rapid commercialization, there is urgent need to redress the following issues related to this technology:

·Standardizing proper design of construction of polyhouses including cost effective and indigenously available cladding and glazing material.

·Developing cost effective agro-techniques for growing of different vegetable crops in the different types of polyhouses and lowering energy costs of the green house environment management.

·Major research activities on growing of vegetables under protected covers should be launched by ICAR and SAU's.

·Import of planting materials, structural designs and production technologies which are not relevant under Indian conditions should be stopped and in turn emphasis should be given to develop own F hybrid varieties so that seed are 1

made available to the growers in time and at cheaper rates.

Popular Structures

·Plastic greenhouses with natural ventilation

·Greenhouses with fan and pad cooling system

·Solar greenhouses (Leh design)

·Walk-in tunnels (Dry temperate areas in HP)

·Plastic low tunnels

·Net houses and Anti-insect cages

·Under ground trenches (Leh and Ladakh region)

Site selection

If possible, locate the greenhouse where it will receive at least 6-8 hours of direct sunlight during the winter months. A good site would also be sheltered from high winds, close to water and electricity, and easily accessible from your home and garden. Avoid deep slopes, gorge areas and areas shaded by buildings or trees during the winters. The best orientation of the greenhouse construction is East-West. This will result in receiving more solar radiations during the winter.

61

Standardizing production technology

When a greenhouse comes in place, the next important step is to select the right crop for its growing with optimum agro-techniques. The technology developed should be simple, easily understandable by growers and cost effective. The initial experiments at YSPUH&F-Nauni and CSKHPKV-Palampur have led to the development of simple growing techniques for tomato and sweet pepper which are adopted by growers. The further refinement in existing technology will definitely go a long way to harness the full potential of greenhouses in vegetable production in the hilly regions.

References:

Chandra P., P.S. Sirohi, T.K. Behera and A.K.Singh. 2000. Cultivating vegetables in polyhouse. Indian Horticulture. 45: 17-25.

Kohli U. K., Manish Kumar, N.P. Dohroo and K.C. Sharma. 2007. Growing media and substrate. In“Protected cultivation of vegetable crops”, CAS in Horticulture (Vegetables), Dr. YSPUH&F- Nauni, Solan, H.P. PP: 37-40.

Kumar Manish., U.K. Kohli, S.K. Gupta and A.Vikram. 2007. Effect of growing media, irrigation regime, fertigation and mulching on productivity of tomato in naturally-ventilated polyhouses in hills. Indian Journal of Agricultural Sciences 77(5): 302-4.

Mangal J.L. and G.R.Singh. 1993. Off-season vegetable production. In: Adv. In Hort. Vol. 6. Vegetable crops: part 2. Pp.673-685.

Nagarajan M., S.Senthilvel and D.Planysamy. 2002. Material substitution in Green house construction. Kisan World. 11:57-58.

Sharma Manish, S. Negi and S. Kumari. 2009. Effect of different growing media and fertigation levels on production of cucumber (Cucumis sativus L.) under protected conditions in the hills. Indian journal of Agricultural sciences. 79 (10): 853-856.

Singh B.1998. Vegetable production in cold desert of India: a success story on solar greenhouses. Acta Horticulturae: 534.

Sirohi P.S. and T.K. Bahera. 2000. Protected cultivation and seed production in vegetables. Indian Horticulture.45: 23-25.

62

Pre and Post harvest Factors in Influencing the Quality of Vegetable Seeds

HS Kanwar and DK Mehta

Seed Technology & Production CentreDr YSP University of Horticulture & Forestry Nauni, Solan 173230 HP

Seeds are regarded as the parent source to bring change in country's economy. A good quality seed is good looking, viable, vigorous, genetically pure, bold and uniform size of the desired type, free from diseases, insect pests, weed seeds, foreign matter, fairly priced, better longevity with high germination percentage, good yielding ability and have wider adaptability. The planting of good seed is essential for the success in crop production. However, producers cannot achieve success with poor seed, even when they give their closest attention on other factors of production. Without healthy and quality seed our all expenditure on irrigation, labour, cultural practices, fertilizers and manures have no value. In addition, seeds need to have good storage quality to ensure that it maintains condition until it is used for sowing.

Concept of quality seed

Genetic quality

• It govern the yield potential of a variety

• This can be achieved through adopting seed chain and production practices like isolation distance, rouging etc .

Physical quality

• It can be achieve through seed processing

Physiological quality i.e. Germination, vigour and health

• It can be improved through various pre and post harvest practices

• Seed Enhancement technologies like seed priming, pelleting, coating etc can be used to further improve the physiological quality of seed before marketing.

Classes of Seed

In the Indian generation system of seed multiplication, there are primarily three categories of seed i.e. breeder seed followed by foundation seed and certified seed. Certified seed is actually sold to the farmers to raise the commercial crop. There is another category of seed known as Labeled Seed in which case there is no certification but labeling is compulsory. Label colour and size have also been specified for each category of seed.

Standards

In India seed certification standards have been prescribed for foundation and certified seed. There are two types of standards; field standards, which apply to standing crop and seed standards which are applicable at seed level. Field standards include isolation requirement, maximum permissible level of off types, inseparable other crop plants, objectionable weed plants, pollen shedders (in male-sterile or A lines), plants infected by seed borne diseases etc. Seed standards relate to genetic purity, physical purity, germination, other crop seeds, weed seeds, moisture content etc.

Land Selection

Land to be used for seed production should be fertile, well drained and free of volunteer plants (self sown plants). Volunteer plants are a very serious problem in Brassica species. Self-sown plants continue to appear for 3 to 4 years. Fields heavily infested with objectionable weeds should be avoided unless effective weed control measures are available.

Isolation

The seed production plot must be isolated from various sources of contamination by a certain minimum distance known as isolation distance. Isolation is more important in cross-pollinated crops to avoid genetic contamination through cross pollination by wind/insect borne pollen whereas in strictly self-pollinated crops it is mainly to avoid mechanical mixture from adjoining plots. Isolation requirement varies from a few meters in self-pollinated crops to hundreds of meters in cross-pollinated crops.

Genetic purity of a seed crop can be maintained by keeping the variety in isolation from other varieties of the same crop and other cross compatible crops.

Isolation can be of

• Space isolation

• Time isolation

• Barrier isolation

• Discarding border rows

Class of Seed Label Colour Label Size

Breeder

Foundation

Certified

Labelled Seed

Golden Yellow

White

Azure Blue

Opel Green

12 cm x 6 cm

15 cm x 7.5 cm

15 cm x 7.5 cm

15 cm x 10 cm

64

Rouging

Rouging is the removal of off type plants and is an important aspect of seed production to maintain varietal purity. Any plant which does not conform to the characteristics of the variety is called an off type. Off types are generally considered to arise from segregation of residual heterozygosity, out-crossing with other varieties, admixtures or natural mutations. Off types could be w.r.t. any character such as plant height, days to flowering, waxiness, pigmentation, ear shape, ear size, ear density, ear colour etc. It is essential that off types are removed before they flower, particularly in cross-pollinated crops, to avoid contamination from off type plants. Rouging may need to be carried out several times during the crop season. Composite, synthetic and open pollinated varieties of cross-pollinated crops generally have broad genetic base and some amount of variability is desirable. Therefore, rouging in such varieties should not be very rigid so that the varietal gene pool is not disturbed. Only obvious off types and diseased plants etc. should be removed.

In addition to rouging all plants that do not conform to the variety description, inseparable other crop plants, objectionable weeds as well as plants infected with seed-borne diseases should also be removed. As a general rule, the off types should be removed and taken away from the seed production plot and destroyed. Light levels are important and dull, excessively bright and windy days should be avoided. The back of the person doing rouging should be towards the sun. This facilitates easier detection of off types.

Field Inspection

The production of foundation and certified seed is supervised and approved by State Seed Certification Agencies. The seed production plots are inspected by the certification staff. The number of inspections varies from a minimum of two to four. Those plots which conform to field standards of certification are approved. Breeder seed has been kept out of the purview of certification as it is not meant for public sale. Moreover, its production is under the direct supervision of a qualified plant breeder. However, breeder seed crop is monitored by a joint inspection team of plant breeders and officials of State Seed Certification Agency and National Seeds Corporation.

Seed Processing

Objective:

• Removal of excess moisture

• Enhancement Physical purity and Freedom from pest

• Removal of impurities, immature seeds, plant materials (dockages), mechanically damaged seed

• Enhance storability

65

Principles of seed processing

Physiological quality of seed

• Germination: High germination is essential to maintain optimum plant population with recommended seed rate.

• Seed Vigour: Vigorous seed is pre-requisite to establish optimum plant population even under adverse conditions.

• Seed Health: Seed free from seed-borne pathogens and insects are essential to maintain plant population and soil health.

Cultural Practices

Cultural practices such as seed bed preparation, fertilization, weeding, irrigation etc. are usually the same for seed crop as recommended for commercial crop. All recommended agronomic practices should be followed to provide conditions for optimal growth and development of plant and seeds which favour production of healthy and vigorous seed. Clean cultivation with proper weed control during seed production makes subsequent cleaning and grading easier. Phosphate and potassium are generally more important for seed crops than for commercial crops and recommended doses must be applied. However, slightly less than the recommended amount of nitrogen should be used in the seed crop especially of cereals to minimize lodging. A crop that lodges badly cannot be effectively rouged and inspected and will not be approved.

Physical difference Suitable machineries

• Seed Size- small to bold • Air Screen cleaner cum grader

• Density- ill filled, immature, light to dense seed

• Specific gravity separator

•

Shape – Round to oval

•

Spiral separator

•

Surface texture- Smooth to wrinkled and

rough

•

Roll mill/ dodder mill

•

Colour of the seed – Light to dark

•

Electronic colour separator

•

Seed vigour-

Size of the plumule, internal status of the seed (Hollowness, insect infestation, impact damage or seed health

•

Soft X- ray sorter

66

Harvesting and Post-harvest Handling of Seed

The germination of seed is of vital importance and the threshers, combine harvesters etc. must be properly set up to thresh the seed without inflicting damage to the seed. The crop should be harvested at proper moisture so as to minimize the damage to the seed. In hybrid seed production, where two parents are involved, the male parent rows are harvested first and moved to a distant place. The whole field is then inspected and broken or lodged male parent plants are removed from the female parent rows. The hybrid seed on the female parent rows is then harvested.

All our efforts in rouging and care during earlier stages may go waste if proper care is not taken during harvesting, threshing, processing, seed treatment, packaging etc. to avoid mechanical mixing. Correct labelling is very important. The threshers, combine harvesters, trailers, threshing floors, processing machinery etc. should be thoroughly cleaned in between handling of different varieties.

Seed Testing, Labeling and Storage

After processing of a given lot, the representative sample is sent to notified seed testing laboratory for analysis. Seed testing is done as per ISTA Rules. If the seed test report is satisfactory i.e. the seed meets the prescribed seed standards then a given seed lot is approved and tags and certificates are issued by the certification agency to the seed producer. The validity period is nine months from the date of test at the time of initial certification. The validity period can be further extended for six months provided on retesting the seed conforms to the prescribed standards w.r.t. physical purity, germination and insect damage for all seeds except vegetatively propagating material for which lot shall be examined for seed standards specified for respective crop.

Seed being a living entity is highly sensitive to ambient weather conditions viz. high relative humidity and temperature, which deteriorates its viability and vigour. Improper handling of seeds also causes mechanical injury and lower down its germination and storability. Therefore, during post-harvest processing and storage seed must be handled properly and protected from high relative humidity and temperature, insect pests and rodents.

Reference:

Aggrawal RL. Seed Technology. Oxford and IBH Publishing, New Delhi, India.

Kanwar H S, Bhattarai D R and Mehta D K. 2010. Seed Technology: Processing, storage and marketing, Jain Brothers, New Delhi, 203p.

Khare D and Bhale MS. 2011. Seed Technology. Scientific Publishers, Jodhpur, 260 p.

McDonald M B & Copeland L O.2005. Seed Production: Principles & Practices, Chapman and Hall, New York, 749 p.

67

Impact of Climate Change on Quality Seed Production of Important Temperate Vegetable Crops

*Ramesh Kumar, Sandeep Kumar, Ashok Thakur and Sanjeev Kumar

Department of Vegetable Science

Dr YS Parmar University of Horticulture and Forestry, Nauni-173 230, Solan*Division of Vegetable Science and Floriculture

Faculty of Agriculture, Main Campus, Chatha, SKUAST-Jammu 180 009, India

Climate change is one of the most important global environmental challenges in the history of mankind. It is greatly affecting the pattern of crop growth in various agro-climatic zones throughout the world, which in-turn is changing the socio-economic conditions of the people. Vegetable production is also not untouched by the changing climatic scenario, it has also affected the seed production of the various temperate vegetables like cabbage, cauliflower, broccoli, brussel's sprouts, knol-khol, kale, European carrots, radish, turnip, beetroot etc. which have specific low temperature chilling requirements. Various marginal areas are becoming unsuitable for seed production of different vegetables viz., late cauliflower, cabbage and other temperate vegetables due to increasing temperature. The problems arise from extreme events that are difficult to predict. More erratic rainfall patterns and unpredictable high temperature spells will consequently reduce crop productivity. Climate change is projected to increase the global temperatures, causes variations in rainfall, increases the frequency of extreme events such as heat, cold waves, frost days, droughts, floods etc. with immense impact on agriculture sector. Moreover, variables of the environment donot act in isolation, but also in combination with one other and with other pressures such as habitat degradation and loss or the introduction of exotic species. All the crop species are likely to be not only directly impacted by the changes in environmental conditions, but also indirectly through their interactions with other species. While direct impacts may be easier to predict and conceptualize, it is likely that indirect impacts are to be equally important in determining the response of plants to climate change.

The hilly areas in India are primarily situated in western Himalayan range extending from Jammu and Kashmir in the west to Arunachal Pradesh in the East. These are represented by states of Jammu & Kashmir, Himachal Pradesh, Sikkim, Assam, Meghalaya, Manipur, Nagaland, Arunachal Pradesh, Parts of Uttar Pradesh, Kumaon, Gadhwal, West Bengal, Darjeeling, Tripura and Mizoram. Temperate vegetables require temperate climate especially during a specific stage of their growth for successful seed production. During this period these vegetables meet the

vernalization (chilling) requirement, a pre-condition necessary for breaking dormancy of plant, thus stimulating the conversion of the vegetative phase into the reproductive phase i.e. induction of flowering and bolting.

Brief history of seed production

For the first time, Government of India encouraged the seed production of temperate vegetables in 1942-43 at Quetta in Baluchistan (now in Pakistan). At the same time initial trials on seed production were also initiated in Kashmir. With the partition of India in 1947, Quetta centre of temperate vegetable seed production went to Pakistan and the supplies of seed were cut off. Thus, it becomes necessary to strengthen the temperate seed programme also at some other suitable locations in India. So, after independence, Govt. of India established a Research Station at Katrain (Kullu valley) Himachal Pradesh in 1949. This station was transferred to Indian Agricultural Research Institute, New Delhi in 1955 with the sole objective of intensifying the improvement work on temperate vegetables and was renamed as IARI Vegetable Research Station and later on as IARI, Regional Station. Till date, the station has been making steady progress in the area of vegetable improvement and seed production resulting in development of large number of varieties and multiplication of their seeds to cater the need of the entire country for breeder and foundation seed especially of temperate vegetables.

Suitable areas for seed production

Our country is gifted with a wide range of agro-climatic conditions, which enables the seed production of different vegetable crops throughout the country in one or the other part. The winter temperature of Kullu and Kashmir valleys is so congenial that neither protection from cold in the field nor provision of storage facilities for over wintering is required. The crops under these conditions can be left in the open for overwintering without any damage. Winter and summers suit to produce seeds of not only temperate vegetables, but also of summer's vegetables. Besides the Kullu and Kashmir valleys, fulfilling the necessary requirement for seed production of temperate vegetable, there are some other areas viz., Vegetable Research Station, Kalpa, Kinnaur where climatic conditions (severe winters and dry hot spring-summers) are quite congenial for quality seed production of temperate vegetable crops. These areas widen the scope for expending the seed industry not for indigenous consumption, but also for export to even some European and western countries, where seed production becomes expensive day by day with the increase in cost of labour.

Methods of seed production0 Seed production of temperate vegetables requires high chilling of 4-7 C for a

period of about 4-6 weeks. The mild summer and low rainfall of hills especially during flowering and seed setting stages are beneficial. In root crops, 'root to seed'

69

and 'seed to seed' methods can be used for seed production, but preferable 'root to seed'. In root to seed method, fully matured roots (before pith development) are harvested, true to the type roots are selected and after giving proper root and shoot cuts are transplanted in a well prepared field. The selection and rouging are done on the basis of foliage characters, root shape, size, color, flesh color, pithiness, and pungency and bolting behavior. Small, deformed, diseased and other undesirable roots are discarded. Hairy forked roots and early or late bolters are also removed. The sowing time should be so adjusted that the roots become available and their stecklings could be set in before chilling months. In heavy snowfall areas where chilling period is long, the roots after uprooting are stored in trenches before the onset of winters and replanting is done in the month of March- April. In such case stecklings are prepared just before planting. The seed is ready for harvesting from July-August in the hills and from May to June in the plains depending upon the weather, crop and cultivar. In case of cole crops 'head to seed' method is mostly followed. When cabbage head are grown for seed, the time of planting is adjusted to obtain full maturity of crop just prior to the normal maturity time. It is being done at Vegetable Research Station, Kalpa, Kinnaur. In Kalpa, transplanting of cabbage for

stseed crop is done at 1 fortnight of July and heads get ready for transplanting with the onset of winters (October-November). The earlier matured heads will not have satisfactory storage condition. Large seed yield of cabbage can be obtained by

stplanting crop in 1 fortnight of July under conditions but in case of Kullu valley

thcondition we can go up to 15 August. Off type plants are roughed when the crop is nearly at maturity. Plants are removed when they don't confirm to excepted standard of non-wrapper leaves, shape, size and appearance of basal and outer leaves. After

0harvesting the crop, the heads are stored in the trenches and require 4 to 6 C temperature for transformation from vegetative to reproductive phase. Before storage cabbage head are treated with Dithane 0.25% and Malathion 0.1% to avoid the disease and insect pest damage during storage. Cabbage plants are stored in trenches having the size of 3 m x 1 m x 1 m. Cabbage plants are stored in slanting position in a 1m width position and cabbage roots should be covered with the 1-2 inch soil. The trenches are covered with the wooden planks. Small holes/openings are kept in the both sides of trench for proper aeration and to maintain almost similar temperature in outside and inside of trench. These holes must be covered with wire mesh to avoid the entry of rats and other rodents. The matured cabbage heads are removed from the trenches during March-April and are replanted in the field at a distance of 60 x 45 cm. After proper establishment of heads in the field, 2-5 cm deep cross-cut is given on the head for initiation of seed stalk from the centre. In 'seed to seed' method plant is allowed to grow in the same place where it was transplanted in the field for head crop. Plants are either allowed to form partial head or they may enter full maturity after winter. In this method typical roughing both for root and shoot portion is not possible and is used for the production of foundation seed.

70

Harvesting is usually done when a noticeable proportion of the pods have become yellow. After the harvesting, pods curing may require 1-2 weeks depending on the weather conditions.

Impact of climate change on pollination

Pollination is a crucial stage in the reproduction of most flowering plants including vegetable crops (Kearns et al. 1998). Change in the Climate may be a vast threat to pollination services due to reduced activity of pollinating agents (Memmott et al. 2007; Hegland et al. 2009; Schweiger et al. 2010). Among all the climatic factors, increase in temperature has highest adverse effect on pollinator interactions. Warming may actually enhance the performance of insects living at higher altitudes, thereby resulting into increased seed setting and yields in the temperate crops growing in these areas. But, rise in temperature in low lying hills adversely affects the activity of pollinating agents and hence the low seed yields.

Hybrid seed production

Cole crops and root vegetables form an important group of cool season vegetables. In general, these are highly cross-pollinated crops and show preponderance of non-additive gene action for most of the economic traits. Hence, heterosis breeding has turned out to be of more relevance. The genetic phenomena of sporophytic self incompatibility and male sterility (particularly cytoplasmic male sterility) have proved instrumental in commercialization of hybrid seed production in these crops.

Use of self incompatibility: Self incompatibility mechanism has been reported by the various workers in kale (Thompson, 1957), sprouting broccoli (Sampson. 1957), cabbage (Adamson, 1965), cauliflower (Hoser-Krauze, 1979), radish and turnip. Commercial hybrid seed production using self incompatibility mechanism is done by way of developing single cross, three-way cross or double cross. In single cross, two self-incompatible but cross-compatible best combiners are planted in alternate rows in isolated plots. The hybrid seed is harvested on both the lines. In three way cross, one single cross and a self-incompatible line are planted in alternate rows. Similarly in double cross, two single crosses are used. In USA, for hybrid seed production of cabbage, top cross is being used. For every 2 or 3 rows of a self incompatible line, one row of a good open pollinated (OP) cultivar as a pollen parent is provided. However, the hybrid seed is harvested from the self incompatible plants only. The main problems being faced in hybrid seed production are depression in S-allele lines by continuous inbreeding, pseudo-compatibility, the effect of environmental factors on the level of self-incompatibility and higher proportion of selfs/sibs in hybrid seed due to lack in proper synchronization of flowering. These

71

could be managed by resorting to vegetative propagation, using the S-allele lines which behave stable under diverse environments and selecting the parental lines which have perfect synchronization in flowering.

Use of male sterility: Genetic male sterility, which is governed by recessive nuclear genes has been reported in cabbage (Rundfeldt, 1960), Cauliflower (Nieuwhof, 1961) and other members of cole group as well. But, during these days Ogura male sterility (Ogura, 1968) i.e., cytoplasmic male sterility has become popular for hybrid seed production in cole crops. Ogura male sterility has been transferred from Japnese radish into cabbage through broccoli with the help of protoplast fusion. R-cytoplasm (Ogura) induced male sterility already present/introduced in any genotype of a cole crop can be transferred into the desired genetic background through backcross method. Beside this, male sterility has also been exploited for hybrid seed production in carrot, radish and beetroot. Hybrid seed production using male sterility mechanism on commercial scale is carried out in the open by providing recommended isolation distance of at least 1000m. Usually for every 2 or 3 rows of A-line, one row of C-line is planted. The lines A and C must have perfect synchrony in flowering for good pollination and seed set. The hybrid seed is harvested from the plants of A-line only. The main problem being faced is the lower quantity of hybrid seed on account of honey-bees preference for the pollen fertile C-line. This could be overcome to a certain extent with appropriate flower morphology and manipulating the ratio of plants of A and C lines, spacing and planting design. Inbreeding depression is another problem which results in low seed production of inbred parental lines and also that of single cross hybrids. Three-and four way (double cross) crosses may prove economic.

Impact of climate change on seed production of cabbage: a case study

A study was conducted during 1981 to 2004 in Kullu valley for the impact of climatic change on the seed yield of cabbage var. Golden Acre (Kumar et al., 2009).

0It was observed that the average maximum temperature of May rose by 1.58 C. The

0minimum temperatures for the months of April and August rose by 2.03 and 2.16 C, respectively. From 1981 to 2004, around 40% reduction in seed production per unit area was noticed. The relative humidity during the month of May did not have any significant effect on seed yield. Correlation coefficients between mean monthly rainfall during May and seed yield (r= -0.49), mean maximum temperature during April and seed yield (-0.36) and maximum temperature during May and seed yield (-0.39) indicate that when temperature rise, it affects seed production of cabbage adversely. Also, if rainfall increases during May, the seed yield is reduced. It has also been observed that the rainfall during August has decreased and during September it has increased resulting in late onset of autumn thereby suggesting that the planting of

72

cabbage should also be delayed at least by a fortnight to avoid incidence of soft rot and increased seed yield.

Future strategies

Climate change is serious constraint, which accounts for enormous losses in terms of seed yield and quality of temperate vegetable crops. So, there is an urgent need to focus our attention on studying the impacts of climate change on growth, development, seed yield and quality of these crops. However, the promotion of modern technology and crop diversification should be tailored according to local conditions. Efforts should be made to uplift the socio-economic condition farmers through rigorous research and development. Researchers, extension personnel, gardeners and farmers should be trained on the issues of climate change. Temperate vegetable crops, which are tolerant to high temperatures, flooding, drought and soil salinity must be identified form the available resources. Uses of bbiotechnological interventions for introgression of important genes, which are adapted to climatic changes, have been widely acknowledged. Some of simple, but effective adaptations strategies include change in the sowing date, use of efficient technologies like drip irrigation, soil and moisture conservations measures, fertilizers management through fertigation, change of crop/alternate crop, increase in input efficiency, pre and post harvest management of economic produce can not only minimize the losses, but also increase the positive impacts of climate change. All these measures can make the horticultural farmer more resilient to climate change. In conclusion, climate change will decrease crop yields in the long-term, unless one slows climate change and/or adapts new management practices and improved cultivars.

References:

Adamson R M. 1965. Self-and cross-incompatibility in early round-headed cabbage. Canadian Journal of Plant Science 45:493-497.

Hegland S J, Nielsen A, Lázaro A, Bjerknes A L and Totland O. 2009. How does climate warming affect plant pollinator interactions. Ecology Letters 12: 184-195.

Hoser-Krauze J. 1979. Inheritance of self-incompatibility and the use of it in the production of F hybrids of cauliflower. Genetica Polonica 20: 341-367.

Kearns C A, Inouye D W and Waser N M. 1998. Endangered mutualisms: the conservation of plant pollinator interactions. Annual Review of Ecology System 29: 83-112.

73

Kumar P R, Yadav S K, Sharma S R, Lal S K and Jha D N. 2009. Impact of climate change on seed production of cabbage in North Western Himalayas. World Journal of Agricultural Sciences 5 (1): 18-26.

Memmott J, Craze P G, Waser N M and Price M V. 2007. Global warming and the disruption of plant pollinator interactions. Ecology Letters 10: 710-717.

Nieuwhof M. 1961. Male sterility in Brussels sprouts, cauliflower and cabbage. Euphytica 10:351-356.

Ogura H. 1968. Studies of the male sterility in Japanese radish with special reference to the utilization of this sterility towards the practical raising of hybrid seeds. Memoirs of the Faculty of Agriculture, Kagoshima University 6:39-78.

Reynolds M P (ed.). 2010. Climate change and crop production. CABI, Wallinford, UK. 285p.

Rundfeldt H. 1960. Untersuchungen zur zuchtung des koptkohls (B. oleracea L. var. capitata). Z. Pflanzenz 44:30-62.

Sampson D R. 1957. The genetics of self-and cross-compatibility in Brassica oleracea. Genetics 42:253-263.

Schweiger O, Biesmeijer J C, Bommarco R, Hickler T, Hulme P, Klotz S, Kuhn I, Moora M, Nielsen A, Ohlemuller R, Petanidou T, Potts S G, Pysek P, Stout J C, Sykes M, Tscheulin T, Vila M, Wather G R and Westphal C. 2010. Multiple stressors on biotic interactions: how climate change and alien species interact to affect pollination. Biological Review 85: 777-795.

Thompson, K F. 1957. Self-incompatibility in marrow stem kale Brassica oleracea var. acephala L. Demonstration of sporophytic system. Journal of Genetics 55:45-60.

74

Vegetable Production and Seed Production under Temperate Conditions

Amit Vikram

Directorate of Extension EducationDr YS Parmar University of Horticulture & Forestry Nauni-173 230, Solan (HP)

Temperate regions can broadly be defined as those areas of the planet falling between either of two intermediate latitude zones of the earth, the North Temperate Zone, between the Arctic Circle and the Tropic of Cancer, or the South Temperate Zone, between the Antarctic Circle and the Tropic of Capricorn. However, within this broad zone many variations of climate from sub-tropical to sub-arctic can be

ofound. Up to 40 north and south latitude the temperate regions are comparatively warmer and altitude has profound impact on temperature conditions. One of the

o characteristic features of temperate regions is low temperature of less than 10 C

oduring winters and moderate temperature between 20-35 C during summers.

India has geographical areas in Himalayas and some in the Nilgiris where climatic conditions are quite close to the temperate regions of the world particularly, with regard to summer and winter temperatures. This offers an opportunity to grow temperate vegetables and produce their seed in the hills, particularly in the dry temperate regions of western Himalayas. The production technology of some of these vegetables as followed in the temperate regions of India particularly Himachal Pradesh is described below:

A. COLE CROPS

CABBAGE

Cabbage is the most important crop of this group after cauliflower. Its cultivation was limited till sixties but with increasing popularity of fast food and awareness about its high nutritive value, tremendous increase in its area has come about. Moreover, it is more hardy and easier to grow than cauliflower. The open pollinated varieties of cabbage are slowly loosing their demand, except Golden Acre and Pride of India.

Varieties: The cabbage cultivars can be classified into three groups i) White Cabbage ii) Red Cabbage iii) Savoy Cabbage. Of these, only White cabbage is of commercial importance in India. Very few red or savoy cabbages are grown in the country. The white cabbages are available in three shapes: pointed, round and flat or drum head. Among these round cultivars are more popular in India.

Early: The best known cultivars in this group are Golden Acre and Pride of India. In the recent past, Pusa Mukta, a variety resistant to black rot has been released. The heads weigh 1-2 kg, are round and take 60-70 days to maturity.

Mid season: The most popular cultivar in Nilgiris is September. It produces round heads, weighing 3-5 kg, takes 85-95 days to maturity and the average yields are 30-35 t/ha.

Late: The most of the cultivars grown in this country are drum shaped viz. Pusa Drum Head, Large Late Drum Head. The heads weigh 5-8 kg, require 110-120 days to maturity and the average yields vary from 35 to 40 t/ha. However, such varieties are not liked because of smaller family size and longer growth period.

Climate: Cabbage is grown as summer crop in hills and in winter in north India. The ooptimum temperature for seed germination is 12-16 C and for growth and heading

o obetween 15-20 C, since the growth is arrested above 25 C. Young plants can withstand higher temperatures and short spells of frost. Many tropical hybrids bred

o in Japan, form tight heads even above 25 C, thus staggering the availability over longer periods.

Soil: Cabbage can be grown on all types of soil. For early crop, sandy loam are considered best, while late crop thrives better on heavier soils, since soil moisture is retained. The plants on heavier soils grow more slowly and thus keeping quality is improved. The optimum pH is 5.5 to 6.5 as the availability of phosphorus is maximum. At lower pH yield is substantially reduced while in saline soils, the plants are more susceptible to diseases particularly club root.

Raising of seedlings: The seed cost of hybrid varieties is very high. Therefore, every seed should be grown judiciously thus, limiting the seed requirement to 150-250g for one hectare of area. Normally one gram of seed is sown per square meter. Before sowing seed should be treated with captan/bavistin/thiram @ 3g/kg. The nursery beds should also be drenched after preparation with three per cent solution of either of these fungicides or the soil is fumigated with formalin to check damping of diseases. Sowing should be done in lines 5 cm apart 1.5 to 2.0 cm deep, to avoid crowding and waste of seed. Normal cultural practices be followed to raise healthy seedlings.

Sowing time: The sowing time depends upon the prevailing temperatures at a particular place. In high hills, the crop is sown from April to June, in mid hills from August to October and in North-Indian plains from September to November depending upon variety. Available heat tolerant hybrids can be grown during summers in mid-hills and plains. In South Western and Southern Peninsula hybrid cabbage can be grown all the year round.

76

Transplanting: Four to six week old seedling should be transplanted, since the delay leads to poor head set, late maturity and low yields for early crop. Plant spacing be kept at 45x45 cm, for late 60x45 cm and for in situ sowings 60x30 cm. For early plantings, when rains are prevalent ridge plantings perform better than flat plantings.

Fertilizers and manures: Cabbage is a heavy feeder especially of nitrogen and potash. The plant nutrient doses largely depend upon soil status, availability of soil moisture and the variety grown. Normally hybrids require higher doses since they remove large amounts of plant nutrients for producing high yields. The manurial schedule of 30 tonnes FYM, 200 kg N, 125 kg P O and 150 kg K O per hectare is 2 5 2

followed for hybrid varieties. If crop is poor a foliar application of 2% urea may be given.

Irrigation: Seedlings should be watered with can for a week for setting in field and thereafter the interval of 10-15 days is followed to keep the soil moist. At the time of maturity irrigation may be stopped, since it may cause splitting of heads. Splitting may also be avoided by shaking heads for partially disturbing the roots.

Hoeing and weeding: Two hoeings and three weedings are sufficient for crop growth and the control of weeds. The hoeingmay be avoided during major growth period as it may damage roots and lower yields.Basalin (0.5 l/ha) as pre-emergence spray has been found quite effected for the control of monocot and dicot weeds. Black polyethylene mulch has also been found effective in controlling weeds, conserving moisture, inducing growth and high yields.

Harvesting and Yield: The crop is harvested when the heads attain a good size and are firm. The harvesting is staggered in OP varieties and uniform in hybrids. The heads are carefully cut with a knife with few non-wrapper leaves. For long distance transport, all the outer leaves are removed.The yield of particular hybrid or OP varieties depends upon growing conditions, management of crop and the season. It may vary between 20-30 t/ha in OP varieties and 50-80 t/ha of hybrid varieties.

EUROPEAN CARROTS

Carrots (Daucus carota L.) originated in south Asia, in what are now Afghanistan, Iran, and Pakistan. Orange carrots soon displaced other colours and today predominate throughout the world. However, in India majority of carrot production is still of red type which is very low in â-carotene, a pre-cursor of vitamin A. There are two distinct groups of carrot, viz. tropical or Asiatic and European or temperate. The European types set seeds only under temperate conditions as they

oneed low temperature of less than 7 C for 50-70 days for flower stalk induction.

Climate: Carrot is a biennial crop grown as an annual for its root. It is a cool season

77

vegetable, but will tolerate warm temperatures early in the growing season. Roots 0attain their optimal colour when the air temperature is 60 to 70 ? F. Root colour can

deepen rapidly when temperatures are within this range three weeks before harvest, but colour can decline at higher temperatures.

Soils: Deep well drained, sandy loam or much soils of pH 5.5 to 7.0 are desirable.

Varieties: Several cultivars of European carrots have been recommended for cultivation in H.P. These are Early Nantes, Chantenay, Pusa Yamdagni and Solan Rachna.

Sowing and season: The soil should be thoroughly pulverised to obtain a fine tilth. Otherwise, it will result in deformed roots.The seeds are sown directly in the field on flat beds or on both sides of the ridges formed at a spacing 30-40cm. The seed requirement is 5-6 kg per hectare. The seeds should be rubbed prior to sowing to remove the fine hair on their surface. Within rows a spacing of 5cm should be maintained so that final plant population comes to about 100-130 per square metre. Seed should not be sown deeper than one centimetre. European carrots can be produced during September onwards in the mid hills while in the high hills and dry temperate zone these are produced during summers and fetch excellent price in the market.

Irrigation: To facilitate quick germination a pre-sowing irrigation is desirable. Irrigation should be done frequently depending upon soil type. Frequent irrigation encourages the growth of taproot and prevents secondary root development.

Manures and fertilizers: Adequate nutrient supply is necessary for superior quality carrot production. 20-30 tonnes per hectare well-decomposed FYM should be applied at the time of land preparation.The carrot crop needs around 40-50kg nitrogen, 40-50kg phosphorous and 80-100kg potassium per hectare. Half of nitrogen and full dose phosphorous are applied as a basal dose. The remaining nitrogen is applied at first hoeing, that is, 30-35 days after sowing.

Harvesting and handling: Summer fresh market carrots are harvested from early July to September. Winter fresh market carrots are harvested from November to December. Fresh market carrots must be over 5 inches long and between 0.75 and 1.5 inches in diameter. A light irrigation should be given just before harvest to facilitate safe removal of roots. Under ambient temperature carrots can be stored only for 2-3 days.

Yield: The yield may vary from 20-35 tonnes per hectare depending upon the season and variety.

78

EUROPEAN RADISHES

Of the six Raphanus species, only R.sativus is cultivated. Most cultivated forms are annuals. The thickened fleshy hypocotyl and upper portion of the root is the primary edible portion, secondary roots branch from the lower taproot. Storage root length and width range from short to very long and slender to thick and shapes may be spherical, cylindrical and tapering or combinations of these.

European varieties: White Icicle, Pusa Himani, Rapid Red White Tipped, Scarlet Globe, Scarlet Long.

Climate: Radish is predominantly a cool-season crop but Asiatic types can tolerate higher temperature. The roots develop best flavour, texture and size at cooler

o otemperature of 10 -15 C.

Soil: Radishes do best on either light mineral soils or muck soils but may be grown on a wide range of soils. However, for good root quality soils should be deep, friable and well drained.

Seed: Radishes are seed propagated and directly sown. Radish seeds are larger than those of Brassica sp., about 100 seeds weigh 1g. Seed rate ranges from 6.25 to 7.5 kg/per hectare. Spacing of 30x7.5 cm for obtaining well sized roots is recommended. Garden radishes are grown at high densities such as 2-5 cm between plants in rows and from 10-20 cm between rows.

Methods of sowing: Radish is sown on ridges. Radish is grown as a companion crop with other vegetable crops also. Seeds are sown on ridges about 23 cm high in small furrows with fine sand or soil mixed by hand. The seed is covered and the soil is made firm around it. For continuous supply, the seeds are sown in succession at an interval of around 12 days.

Nutrient requirements: Being a quick growing root crop, the soil should be heavily fertilised, so that nutrients may be readily available to the plants. A basal dressing of 25 to 40 tonnes per hectare of well rotten FYM or compost is added in the field at the time of soil preparation. Fertilizer dosage may vary due to differences in fertility of soil. However for Himachal Pradesh, 100 quintals FYM, 400 kg CAN, 315 kg SSP and 60 kg MOP per hectare has been recommended.

Irrigation:If the moisture is not enough in the field after sowing the seeds, light irrigation is given and later on the crops is irrigated when the plants are 5 to 7.5 cm long and three to four leaves are formed. Generally, irrigation should be carried out every four days.

Inter-cultivation: Two or three weeding may be necessary to minimize the seasonal weeds. The third weeding, if necessary, is carried out 15 days after second weeding.

79

At the time of second weeding, thinning of thick sown plots should be done which may vary depending upon the root size of the cultivars.

Harvesting: All harvesting is done by hand. Radishes are pulled and tied in bunches. Radishes should be kept moist and cool at all times to prevent dehydration. Black spot is reduced by washing radishes in chlorinated water. Yield of European radishes is lesser and may range between 7-10 tonnes per hectare.

EUROPEAN TURNIPS

The turnip (Brassica rapa L.) possibly originated in eastern Afghanistan and western Pakistan, the mediterranean region may be another primary centre. There are two types of turnips cultivated in India: European type (biennial and mostly self incompatible) and Asiatic types (annual).

Cultivars: Temperate cultivars are quick growing, good in quality and possess early maturity. Some cultivars of this group are Purple Top White Globe (PTWG), Golden Ball, Early Milan Red Top (EMRT) and Pusa Chandrima.

Soil: Use deep loam or sandy loam soil types that have good drainage. It is desirable to have a good amount of organic matter in the soil as well. Soils with good drainage are essential for fall and winter harvested crops.

Sowing: The seed rate is 3-4 kg per hectare. Turnip contains about 450 seeds per gram. Hot water or fungicide treated seed should be sown. Hot water treatment is

ocarried out at 52 C for 25-30 minutes, the net seed is then immediately cooled and dried. In mid hills, August-October and high hills, March-August.

Spacing: For fresh or vegetable production turnips should be spaced 30 cms apart between the rows and 10 cm apart within the rows.

Fertilizer: FYM should be applied a year before seed sowing. FYM application has been recommended to be 100 quintals per hectare, CAN 250 kg per kha, SSP 315 kg per ha and MOP 65 kg per hectare. CAN should be applied in three split doses. First at the time of sowing and second and third at the time of earthing up and another month after that.

Irrigation: Apply water for tender growth and maximum availability of nutrients. This crop may require 8-12 inches of water depending upon the planting date, seasonal variation, and variety. Soil type does not affect the total amount of water needed, but does dictate frequency of water application. Lighter soils need more frequent water application, but less water applied per application.

Harvesting: Harvesting time depends upon cultivars which may mature in 50 days to as long as 100 days from sowing. For fresh market, harvest by hand pulling when

80

the soil is comparatively dry so that a minimum of dirt adheres to the roots. For processing purposes, harvesting can also be carried out by mechanical methods (if available). During harvest, roots should be handled with care to reduce injury and rots during storage.

Yield: Yield varies from 20-25 tonnes per hectare depending upon cultivar and season.

TEMPERATE VEGETABLE SEED PRODUCTION

Seed production of temperate vegetables is the most important aspect, which delineates temperate vegetables from other vegetables. For successful seed production, most temperate vegetables are required to be subjected to vernalization/ chilling at vegetative stage before they can form flower-stalk. Moreover, some of the varieties of cauliflower particularly the late cauliflowers though are capable of setting seeds without chilling yet at the time of seed setting moderate summer conditions prevalent in temperate zone are required.

Some essential practices for seed production of temperate vegetables are given below:

1. Cabbage

i) Head production: Heads are produced in hills during May to October planting is done slightly later than the normal crop so that oversized heads are not formed.

ii) Pulling of heads with roots: In the month of November-December, true to type heads are pulled along with stumps and roots and their non-wrapper leaves are removed.

iii) Storage of heads in the trenches: Cabbage heads along with intact stump and roots are stored in trenches of the size 6'x3'x4'. These trenches are covered with GI sheets and soil taking precaution that rain or snow water does not enter the trench. Heads are allowed to vernalize at a temperature of 2-4oC for 2 to 3 months.

iv) Replanting the heads in spring: In the months of March, holes are made in the field with the help of a crow bar, heads are replanted in these holes, and soil is pressed around it. A 2-3” deep cross cut is given at the top of the head to facilitate easy emergence of flower stalk.

v) Seed harvesting and curing: The branches bearing the siliques are cut on different dates depending upon their maturity with sickle and left for curing in shade. The seed is extracted by beating the shoots with sticks.

81

European carrots, turnip and radishes

Stecklings slightly less than full size roots are raised by planting seeds in the month of June-July in high hills and the roots are pulled out in the month of November. The roots are selected on the basis of root shape and other true to type characters. The leaves of the roots are chopped off and the stecklings stored in trenches at 2-5oc temperature for 2 to 21/2 months in trenches similar to cabbage. In the month of March, the selected roots are replanted in the field. Flower shoots start emerging in April. Seed bearing umbels and shoots are harvested periodically from August to September. It is cured and threshed subsequently for extraction.

References:

Bassett, M.J. 1986. Breeding Vegetable Crops. AVI Publishing Co. Inc., Westport Connecticut USA

Nieuwhof, M. 1969. Cole Crops: Botany Cultivation and Utilisation. World Crops Books, Leonard Hill, London

Ryder, E.J. 1979. Leafy Salad Vegetables. AVI Publishing Co. Inc., Westport Connecticut USA

Thompson, H.C. and Kelly, W.C. 1979. Vegetable Crops. Tata Mcgraw Hill Publishing Co. Ltd. New Delhi

Wein, H.C. (Ed.) 1997. Physiology of Vegetable Crops. CABI Publishing, London

82

Production Technology of Cucumber under Changed Climatic Conditions

Ramesh Kumar, Sandeep Kumar, KS Thakur and Dharminder Kumar

Department of Vegetable ScienceDr Y S Parmar University of Horticulture and Forestry, Nauni-173 230 Solan (HP)

Cucumber (Cucumis sativus L.) is one of the most important cucurbitaceous vegetable crop grown extensively in tropical and sub-tropical parts of the country. It

this considered as 4 most important vegetable crop after tomato, cabbage and onion. Cucumber is a thermophilic and frost susceptible crop species, growing best at a temperature above 20°C. It is grown for its tender fruits, which are consumed either raw as salad, cooked as vegetable or as pickling cucumber in its immature stage. It is a rich source of vitamin B and C, carbohydrates, Ca and P.

In the recent years, due to changing climatic conditions in the country, production and quality of most vegetable crops have been directly and indirectly affected by high temperatures and exposure to elevated levels of carbon dioxide and ozone. In general, the vegetables those require hot temperatures to grow, have faster growth and better quality as the temperatures rise until it reaches the growth inhibition limit (35? ). The temperature in the hilly as well as in the plain regions of the country is increasing rapidly due to global warming, which has resulted in poor yield and reduced quality of cucumber. Rise in the temperature during summer months has affected the sex expression, flowering, pollination and fruit setting in cucumber. Extremely high temperatures can even cause early flower drop in cucumber. Moreover, exposure of cucumber plants to heat stress during fruit development stage causes bitterness of fruits. Various other climatic factors like humidity, rainfall, light intensity etc. also affect the normal growth and development in cucumber if they are not provided in optimum range during the growing season. The various strategies/techniques developed to overcome the adverse effects of climate change on cucumber production have been given here under:

Improved varieties/hybrids:

The main goal of research on cucumber in India is to improve productivity on sustainable basis through developing biotic and abiotic resistant varieties/hybrids coupled with quality attributes. In India, several research institutes and universities have utilized a number of cultivated and wild species of cucumber to develop improved varieties/hybrids. But, due to changing climatic conditions, existing varieties of cucumber are becoming susceptible to various biotic and abiotic stresses. Hence, there is an immense need to develop new varieties/ hybrids of cucumber which are resistant/tolerant to high and low temperatures, water logging, soil salinity etc.

Improved agro-techniques:

The yield potential of cucumber could be increased by adopting the standardized agro-techniques and plant protection measures. Mulching has been very effective for hybrid crops as it moderate the soil temperatures. During summer and rainy seasons, straw mulch has been found effective. Use the PGR has been proven to be beneficial for earliness, quality and yield in cucumber. Foliar spray of ethephon (100-500 mg/l), GA (10 mg/l) and TIBA (25-50 mg/l) increases the yield in cucumber. Staking in cucumber has been found to be very effective in getting maximum yield and better quality of fruits. In this regard, pruning i.e., single stems are allowed to grow with 2-3 fruiting branches in cucumber is also beneficial. In general, 25-30 tones of farm yard manure, 25 kg nitrogen, 40 kg phosphorus and 40-60 kg potassium as basal dose is sufficient for healthy crop stand in cucumber.

Use of grafting techniques

Grafting is the uniting of two living plant parts so that they grow as a single plant. Grafting of vegetable plants is a common practice in Japan, Korea, and several European countries; its main purpose is to control soil-borne diseases and nematodes. In addition, grafted plants may have higher yields, improved tolerance to environmental stresses such as high boron, soil salinity, and low soil temperatures under changing climatic scenerio. Grafting in cucumber was first used commercially in 1960's. There are various manual grafting methods in cucumber viz., hole insertion, modified hole, tongue approach, slant-cut, splice and double splice grafting which are being used on commercial scale and recently, grafting machines have been developed to produce the huge amount of grafted plants required. Cucumber can be grafted on inter-specific squash and fig leaf gourd rootstocks. In Japan, cucumber rootstock is often selected based on its influence on fruit quality, as certain rootstocks reduce the deposition of silicon over the fruit epidermis or bloom and therefore improve the fruit quality. Rootstock efficacies are influenced by compatibility to the selected scion, existing disease pressure, and climate conditions. Hence, it is very important to test the selected candidate rootstocks at a small scale before introducing the rootstock for larger scale. In spite of its advantages, there are some problems associated with grafting. These include the additional cost, graft incompatibility that commonly appears to cause physiological disorders, and reductions in yield, fruit quality, and flower formation. Therefore, initiating or increasing the use of grafted plants should be done only after the benefits and risks of grafted seedlings have been fully understood (Edelstein, 2004).

Protected cultivation

The productivity and quality of cucumber grown under open field conditions is generally low. Cucumber under open fields is grown in two seasons; one in summer and second in rainy season. During winter season, it cannot be grown under open field conditions. Keeping in view the abiotic stresses in changing climate under open field, production technology of cucumber has been developed and standardized

84

for cultivation under two types of protected structures namely, naturally ventilated greenhouse and insect-proof net house. The yield of cucumber in protected structures can be increased manifold as compared to their open field cultivation. Moreover, production of cucumber in greenhouse or net house has led to the minimum use of pesticides, which is not possible under open field cultivation. The demand of fresh salad varieties of cucumber is increasing day by day and growing this crop under protected conditions is becoming profitable proposition. Vegetable growers, for getting higher prices from their off-season produce, often try to send their produce to the market early in the season and also try to extend the growing season for selected vegetable crops for the purpose of obtaining marketing advantage of their off-season produce. The production technology of parthenocarpic cucumber has been developed and standardized for its cultivation under naturally ventilated greenhouse conditions. Three crops of parthenocarpic cucumber can be grown over a duration of 10-11 months under naturally ventilated greenhouse conditions with productivity ranging between 120-130 t/ha with very high quality fruits. This technology eliminates stresses due to biotic and abiotic factors and the use of pesticides can be minimized. The technology is highly remunerative for the growers of Jammu and Kashmir (up to Jammu region), Himachal Pradesh (low hills and Plains), Punjab, Haryana, Delhi, U.P., Uttrakhand (low hills and Tarai region), NE states, West Bengal, Maharashtra and Karnataka.

Plastic low tunnel technology

Plastic low tunnels provide the best way for off- season cultivation of cucumber during winter season by modifying the microclimate around the plants. Low tunnels also offer several advantages like protection of the crop from frost, hails, and crop advancement from 30-40 days over their normal season of cultivation. This low cost technology for off season cultivation of cucumber is highly suitable and may be quite cost effective for the growers in northern parts of the

0country, where the night temperature during winter season goes below 8 C for a period of 30-40 days. This technology has been developed for off-season cultivation of cucumber for taking full advantage of the prevailing high market prices of the off-season produce. The major steps involved in this technology are as under:

i) Nursery raising for off-season cultivation of cucumber

In India, cucumber is mainly sown by seeds during their normal season of cultivation. Seedlings of cucumber cannot be raised through traditional system of nursery raising on soil beds, because it does not tolerate against slightest damage to its root and shoot system during their uprooting and transplanting. Thereafter, a method of nursery raising was evolved in which off-season seedlings were raised in small polyethylene bags and plastic plug trays by using coco-peat, vermiculite and perlite as soil-less media in 3:1:1 ratio on volume basis. This technique is not only efficient in vigorous root development but also suitable to avoid any damage to the roots and shoots of the seedlings at the time of transplanting. This technology is economical and suitable for the cucumber growers in northern plains of India,

85

because with the introduction of this technique, farmers can grow large number of seedlings as per requirement for off-season cultivation for fetching high price of their off-season produce. Seedlings are raised in the nursery greenhouse in plastic pro-trays having 1.5" cell size in soil-less media in month of December or January and 28-32 days old seedlings at four leaf stage are transplanted under row covers or plastic low tunnels in the open field from mid January to mid February, when the night temperature is very low in northern parts of the country. Nursery can also be raised even in polythene bags under very simple and low cost protected structures like walk-in tunnels or in locally available plastic trays in soil less media as per the need of the area.

ii) Preparation of beds, transplanting of seedlings and covering of plastic

Transplanting of the seedlings is done in a single row on each bed at a planting distance of 50 cm on drip system of irrigation. Distance between the rows in usually kept 1.5 to 1.6 m. Before transplanting of the seedlings on beds, flexible galvanized iron hoops are fixed manually on a distance of 1.5 m to 2.5 m. The width of two ends of hoop is kept 40-60 cm with a height of 40-60 cm above the levels of the beds for covering the plastic on the rows or beds for making low tunnels. Transparent, 30 micron, IR grade plastic is generally used for making low tunnels, which reflects infra-red radiation to keep the temperature of the low tunnels higher than outside field. Now-a-days with the introduction of biodegradable plastic for making low tunnels and for mulching purposes, it is not only eco-friendly but it may be sustainable technology for off-season vegetable production. This biodegradable plastic is available according to the requirement of the duration one want to cover the crop or use as mulch in the crop. After that period the plastic after receiving sufficient sunlight, it becomes brittle. The film eventually breaks down into small flakes and finally completely composted in the soil. The plastic is usually covered in the afternoon after transplanting. The plastic can be vented or slitted during the growing season as the temperature increase within the tunnels during the peak day time. Generally, 3-4 cm size vents are made on eastern side of the tunnels just below the top on a distance of 2.5 to 3.0 m after transplanting, and later on the size of the vents can be increased by reducing the distance between two vents with the increase in the temperature and ultimately the plastic is completely removed from the plants in month of February and March depending upon the date of transplanting growth of the crop and prevailing night temperature in the area.

iii) Pollination under plastic low tunnel crops

Cucumber is monoecious in sex form and needs pollination, which is usually performed by honeybees (Apis melifera). When there is complete flowering bees can work in tunnels easily through the vents, made on the plastic. For effective pollination in cucumber, one beehive, having 30000-50000 workers is sufficient for one-acre area. The beehive box is always kept on the northwest side of the field for effective working of the bees.

86

iv) Harvesting and crop advancement

Cucumber can be transplanted from first week of December to first week of February and can be advanced 30-60 days over their normal season of cultivation. If the crop has been transplanted in first week of February, the fruits will be ready for harvesting in third week of April. Fruits from the mid January transplanted crop can be harvested in first week of April, which is normally 30-40 days early than the normal season. Off-season fruits produced under low tunnels can fetch very high price in the market. This technology is quite economical for growing off-season vegetables in peri-urban areas of the northern plains of the country under changing climatic conditions.

References:

Chaudhary, B. 1971. Vegetables. National Book Trust, India, New Delhi.

Edelstein M. 2004. Grafting vegetable-crop plants: pros and cons. Acta Horticulturae 659 (1): 235-238.

Fageria M S, Chaudhary B R and Dhaka R S. 2003. Vegetable Crops Production Technology.Vol. II . Kalyani Publishers: New Delhi. 283 p.

http://www.krishisewa.com/articles/cucurbitspltt.html

Kalbarczyk Robert. 2010. Climatic Risk of Field Cultivation of Cucumber (Cucumis sativus L.) in Poland. Notulae Botanicae Horti Agrobotanici Cluj-Napoca 38 (3): 157-168.

Rai N and Yadav D S. 2005.Vegetable Science and Technology in India. IBH Publication, New Delhi. 567 p.

Swarup Vishnu. 2006. Vegetable Science and Technology in India. Kalyani Publishers, New Delhi. 656 p.

87

Production Technology of Vegetable Crops under Changing Climate with Reference to Organic

Vegetable Production

Kuldeep Singh Thakur, Ramesh Kumar and Dhaminder Kumar

Department of Vegetable ScienceDr YS Parmar University of Horticulture & Forestry, Nauni, Solan-173 230

Agriculture today faces the challenge of having to adapt and respond to climate change and reduce greenhouse gas emissions. This challenge can be met through organic agriculture.

On a global scale, the potential for food production is projected to increase owith increases in local average temperature over a range of 1-3 C, but above this it is

projected to decrease (IPCC, 2007). Given that warming by the end of the 21st century (2090-2099) will be worse than expected and that the best estimates project a

o orise of 1.8-4 C, and a likely range of 1.1-6.4 C, the world is likely to see a decline in food production.

For developing countries, including where some of the poorest people live and farm, the projections of climate change's impacts on agriculture are dire. Climate change will cause yield declines for the most important crops and result in additional price increases for the world's staples - rice, wheat, maize and soybeans (Nelson et al., 2009).

The relationship between climate change and agriculture is however a two-way one; climate change in general adversely affects agriculture and agriculture contributes to climate change in several major ways.

Agriculture releases a significant amount of carbon dioxide (CO ), methane 2

(CH ) and nitrous oxide (N O) into the atmosphere amounting to around 10-12% of 4 2

global anthropogenic greenhouse gas emissions annually, mostly methane from livestock raising, biomass burning and wet cultivation practices, and nitrous oxides from the use of synthetic fertilizers. If indirect contributions (e.g., land conversion to agriculture, fertilizer production and distribution and farm operations) are factored in, some scientists have estimated that the contribution of agriculture could be as high as 17-32% of global anthropogenic emissions (Bellarby et al., 2008).

Organic agriculture has both adaptation and mitigation potential

The challenge is therefore to design an agriculture that adapts and responds to the changes in climate experienced, as well as reduces greenhouse gas emissions. This challenge could be met through organic agriculture.

By increasing resilience within the agro-ecosystem, organic agriculture increases its ability to continue functioning when faced with unexpected events such as climate change (Borron, 2006). Resiliency to climate disasters is closely linked to farm biodiversity; practices that enhance biodiversity allow farms to mimic natural ecological processes, enabling them to better respond to change and reduce risk. Thus, farmers who increase inter-specific diversity via organic agriculture suffer less damage compared to conventional farmers planting monocultures (Borron, 2006; Ensor, 2009; Niggli et al., 2008). Moreover, the use of intra-specific diversity (different cultivars of the same crop) is insurance against future environmental change.

Organic farming practices that preserve soil fertility and maintain or increase organic matter can reduce the negative effects of drought while increasing productivity (ITC and FiBL, 2007; Niggli et al., 2008). Water-holding capacity of soil is enhanced by practices that build organic matter, helping farmers withstand drought (Borron, 2006). In addition, water-harvesting practices allow farmers to rely on stored water during droughts. Other practices such as crop residue retention, mulching and agro-forestry, conserve soil moisture and protect crops against microclimate extremes. Conversely, organic matter also enhances water capture in soils, significantly reducing the risk of floods (ITC and FiBL, 2007; Niggli et al., 2008).

Indigenous and traditional knowledge are a key source of information on adaptive capacity, centred on the selective, experimental and resilient capabilities of farmers (ITC and FiBL, 2007; Niggli et al., 2008). Many farmers cope with climate change in different ways: by minimizing crop failure through increased use of drought-tolerant local varieties, water-harvesting, extensive planting, mixed cropping, agro-forestry, opportunistic weeding and wild plant gathering. Traditional knowledge, coupled with the right investments in plant breeding, could yield new varieties with climate adaptation potential.

On the other hand, agriculture has the potential to change from being one of the largest greenhouse gas emitters to a much smaller emitter and even a net carbon sink, while offering options for mitigation by reducing emissions and by sequestering CO from the atmosphere in the soil. The solutions call for a shift to 2

more sustainable farming practices that build up carbon in the soil and use less chemical fertilizers and pesticides (Bellarby et al., 2008; ITC and FiBL, 2007).

89

There are a variety of organic farming practices that can reduce agriculture's contribution to climate change. These include crop rotations and improved farming system design, improved cropland management, improved nutrient and manure management, improved grazing-land and livestock management, maintaining fertile soils and restoration of degraded land, improved water management, fertilizer management, land use change and agro-forestry (Bellarby et al., 2008 and Niggli et al., 2008).

Niggli et al. (2008) estimated that a conversion to organic agriculture would considerably enhance the sequestration of CO through the use of techniques that 2

build up soil organic matter, as well as diminish N O emissions by two-thirds due to 2

no external mineral nitrogen input and more efficient nitrogen use. Organic systems have been found to sequester more CO than conventional farms, while techniques 2

that reduce soil erosion convert carbon losses into gains (Bellarby et al., 2008; ITC and FiBL, 2007; Niggli et al., 2008). Organic agriculture is also self-sufficient in nitrogen due to recycling of manures from livestock and crop residues via composting, as well as planting of leguminous crops (ITC and FiBL, 2007).

Conclusion

Redesigning agriculture in an era of climate change entails investing more resources, research and training into, providing appropriate policy support to, and implementing national, regional and international action plans on organic agriculture. Doing so will not only be beneficial in terms of climate adaptation and mitigation, but will also be a paradigm shift towards increasing productivity while ensuring sustainability and meeting smallholder farmers' food security needs.

Maximizing the synergies between adaptation and mitigation means that these strategies should be developed simultaneously. In particular:

ØThere should be more research and action on adaptation measures in agriculture, especially in developing countries in order to assist farmers there to reduce the adverse impacts of climate change on agriculture.

ØAction plans for mitigation measures for agriculture should be urgently researched and implemented.

ØFinancing assistance for adaptation and mitigation measures in the agriculture sector in developing countries should be prioritized.

ØArrangements should be made for the sharing of experiences and the transfer of good practices in agriculture that can constitute mitigation and adaptation.

ØGiven the many advantages of organic farming and sustainable agriculture,

90

in terms of climate change as well as social equity and farmers' livelihoods, there should be a much more significant share of research, personnel, investment, financing and overall support from governments and international agencies that should be channeled towards sustainable agriculture. Promotion of sustainable agriculture can lead to a superior model of agriculture from the environmental and climate change perspective, as high-chemical and water-intensive agriculture is phased out, while more natural farming methods are phased in, with research and training programmes also promoting better production performances in sustainable agriculture.

With appropriate focus on organic agriculture as providing adaptation, mitigation and increased productivity options, a 'win-win-win' scenario for agriculture is possible. Importantly, organic agriculture approaches are also accessible to small-scale and poor farmers who depend on biodiversity, soil health and locally-available resources in agricultural production.

References:

Bellarby, J., Foereid, B., Hastings, A. and Smith, P. 2008. Cool farming: Climate impacts of agriculture and mitigation potential. Greenpeace International, Amsterdam.

Borron, S. 2006. Building resilience for an unpredictable future: How organic agriculture can help farmers adapt to climate change. FAO, Rome.

Ensor, J. 2009. Biodiverse agriculture for a changing climate. Practical Action, UK.

IPCC. 2007. Summary for Policymakers. In: Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. [M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson (eds.)]. Cambridge University Press, Cambridge, UK, 7-22.

ITC and FiBL (Research Institute of Organic Agriculture). 2007. Organic Farming and Climate Change. ITC, Geneva.

Niggli, U., Fliessbach, A. and Hepperly, P. 2008. Low Greenhouse Gas Agriculture: Mitigation and Adaptation Potential of Sustainable Farming Systems. FAO, Rome.

91

Role of Biofertilizers in Enhancing the Vegetable Productivity under Organic Farming Systems

Kuldeep Singh Thakur and Dhaminder Kumar

Department of Vegetable ScienceDr YS Parmar University of Horticulture & Forestry, Nauni, Solan-173 230

Application of bio-fertilizer is of great significance in organic farming. As they play a nutritional stimulatory and the therapeutic role in improving growth, yield and quality of vegetable crops. Inoculations of vegetable crops with different bio-fertilizers have depicted an encouraging response both in terms of increasing yield, quality and soil fertility. The field response of Rhizobium is encouraging as reported by a number of research workers. Azotobacter and Azospirillum depicted a significant influence on vegetable crops, resulting in nitrogen economy of 25-50% and increase in yield 20-30 %. Similarly phosphorus solubilizers can also save in general 20-40% phosphorus fertilizers and can enhance the crop yields by 25-30%.

Biofertilizers are microbial inoculants or carrier based preparations containing living or latent cells of efficient strains of nitrogen fixing, phosphate is solublizing and cellulose decomposing microorganisms intended for seed or soil application and designed to improve soil fertility and plant growth by increasing the number and biological activity of beneficial microorganisms in the soil.

The objective behind the application of biofertilizers /microbial inoculants to seed, soil or compost pit is to increase the number and biological / metabolic activity of useful microorganisms that accelerate certain microbial processes to augment the extent of availability of nutrients in the available forms which can be easily assimilated by plants. The need for the use of biofertilizers has arisen primarily due to two reasons i.e. though chemical fertilizers increase soil fertility, crop productivity and production, but increased / intensive use of chemical fertilizers has caused serious concern of soil texture, soil fertility and other environmental problems, use of biofertilizers is both economical as well as environment friendly. Therefore, an integrated approach of applying both chemical fertilizers and biofertilizers is the best way of integrated nutrient supply in vegetable crop production.

Biofertilizers used in vegetable crops:i) Symbiotic nitrogen fixers Rhizobium sp.ii) Non-symbiotic, free living nitrogen fixers Azotobacter, Azospirillum etc. iii) Phosphate solubilizing microorganisms (PSM) Bacillus Pseudomonas,

Penicillium Aspergillus etc. iv) Mycorrhiza

Role of Biofertilizers in enhancing soil fertility and crop productivity

Biofertilizers are known to play a number of vital roles in soil fertility, crop productivity and production in agriculture as they are eco friendly and cannot at any cost replace chemical fertilizers that are indispensable for getting maximum crop yields. Some of the important functions or roles of Biofertilizers in agriculture are:

1. They supplement chemical fertilizers for meeting the integrated nutrient demand of the crops.

2. They can add 20-200 kg N/ha year (eg. Rhizobium sp 50-100 kg N/ha year; Azospirillum , Azotobacter: 20-40 kg N/ha /year) under optimum soil conditions and thereby increases 15-25 percent of total crop yield.

3. They can at best minimize the use of chemical fertilizers not exceeding 40-50 kg N/ha under ideal agronomic and pest-free conditions.

4. Application of biofertilizers results in increased mineral and water uptake, root development, vegetative growth and nitrogen fixation.

5. Some Biofertilizers (eg, Rhizobium, Azotobacter sp) stimulate production of growth promoting substance like vitamin-B complex, Indole acetic acid (IAA) and Gibberellic acids etc.

6. Phosphate mobilizing or phosphorus solubilizing biofertilizers / microorganisms (bacteria, fungi, mycorrhiza etc.) converts insoluble soil phosphate into soluble forms by secreting several organic acids and under optimum conditions they can solubilize / mobilize about 30-50 kg P O /ha 2 5

due to which crop yield may increase by 10 to 20%.

7. Mycorrhiza when used as biofertilizers enhance uptake of P, Zn, S and water, leading to uniform crop growth and increased yield and also enhance resistance to root diseases and improve hardiness of transplant stock.

8. They liberate growth promoting substances and vitamins and help to maintain soil fertility.

9. They act as antagonists and suppress the incidence of soil borne plant pathogens and thus, help in the bio-control of diseases.

10. Nitrogen fixing and phosphate mobilizing in bio-fertilizer enhance the availability of plant nutrients in the soil and thus, sustain the agricultural production and farming system.

11. They are cheaper, pollution free and renewable energy sources

12. They improve physical properties of soil, soil tilth and soil health in general.

93

13. They improve soil fertility and soil productivity.

14. Bio-inoculants containing cellulolytic and lignolytic microorganisms enhance the degradation/ decomposition of organic matter in soil, as well as enhance the rate of decomposition in compost pit.

15. Azotobacter inoculants when applied to many non-leguminous crop plants, promote seed germination and initial vigor of plants by producing growth promoting substances.

16. Plays important role in the recycling of plant nutrients.

94

Production Potential of Under Exploited Vegetable Crops*,Dharminder Kumar, Ramesh Kumar, KS Thakur, Ashok Thakur

Prabal Thakur and Sandeep Kumar

Department of Vegetable Science*Department of Seed Science and Technology

Dr YS Parmar University of Horticulture and Forestry, Nauni, Solan, HP 173 230

India exhibits extreme variations in agro-climatic regions and floristic diversity. Twenty agro–climate regions occur in India based on physiographic, climate and cultural feature (Sehgal et al., 1992). Out of the estimated 75,000 species of edible plants (Gautam and Singh, 1998), only about 150 have been widely used. Of these about 30 species provide 90% of the world's food. The Indian subcontinent represents one of the richest diverse genetic resources. The Indian center of origin and diversity enjoys a rich gene pool of economically important species including both annual perennial plants. More than 15,000 species of flowering plants are indigenous to this region including over 160 domestic species of economic importance, 320 species of wild ancestral forms and approximately 800 species of ethno botanical origin. Global diversity in vegetable crops is estimated at about 400 species, with about 80 species of major and minor vegetables reported to have originated in India (Chadha, 2009).

The use of the term underutilized to refer to categories of wild and cultivated plants invariably gives rise to a discussion of what the word actually means. In general it is commonly applied to species whose potential has not been fully realized. Here we define underutilized species as “those non-commodity crops, which are part of a larger biodiversity portfolio, once more popular and today neglected by users' groups for a variety of agronomic, genetic, economic, social and cultural factors.” (Padulosi and Hoeschle-Zeledon, 2004). Underutilized vegetables are the “species with under-exploited potential for contribution to food security, health (nutritional / medicinal ) , income generation, and environmental services” ( Jaenicke and Hoeschle-Zeledon, 2006) ”. Underutilized crops are often presented as 'new crops', not because they are 'new' but because they have been taken up by commercial companies and researchers for a new market. In reality, local communities have used these species for generations but the current loss of local knowledge means that their traditional uses are being forgotten. The leaves of black nightshades (Solanum nigrum) provide appreciable amounts of minerals including calcium, iron and phosphorous, Vitamins A and C as well as proteins and amino acids such as methionine, scarce in other commonly marketed vegetables.

FEATURES OF UNDERUTILIZED SPECIES:

üHighly adapted to agro-ecological niches and marginal areasüRepresented by ecotypes or landraces.üCultivated and utilized drawing on indigenous knowledge.üHardly represented in ex situ gene banks.üRequire only limited external inputs for production.üSuitable for organic productionüSuitable for cultivation on marginal land (poor soil fertility, etc.)üFit into small-scale farming systemsüPossess traditional, local and/or regional importanceüEasy to store and process by resource-poor communitiesüLocal Market opportunities availableüPossess high nutritional and/or medicinal valueüOffer multiple uses (Global Facilitation Unit (GFU), 2002)

Many Indigenous vegetables (IVs) are underutilized, planted mainly in home gardens, used only by a small group of people in very limited geographical area and some are grown only for a very special purpose. (Engle and Faustino, 2007).Very often IVs are underutilized in spite of their growing importance. Possible reasons for underutilization

ØLack of available germplasm for widespread use,

ØLack of seeds,

ØLack of information on use and importance,

ØLack of information about their performance and input requirements and lack of information on how they can fit into production systems.

INDEGENOUS TRADITIONAL PERENNIAL VEGETABLES:

Amaranthus tricolor, A. dubius and A. tristis- major ones cultivated as vegetables Amaranth greens, poor man's spinach,Leaves good source of vit. A, B6, C, riboflavin, folate, and dietary minerals including calcium, iron, magnesium, phosphorus, potassium, zinc, copper, and manganese.Enhydra fluctuans; Water cress, Marsh herb,Tender twigs eaten as vegetables; laxative, demulcent. Fagopyrum esculentum; common buckwheat,F. tataricum; bitter buckwheat Leaves and young shoots consumed as a potherb. Contains rutin, which reduces haemophilia and heart attack chances. Ipomoea aquatica;Kangkong, water spinach,Tender twigs used as vegetable or added to sauces and soups.Rich in iron, calcium, vit. B and C.Mildly laxative, used to cure diabetes; juice used as emetic, dried latex purgative.

96

Rumex vesicarius, R. acetosella, R. patientia, R. scutatus; Sheep sorrel, Khatta palak,Mostly consumed raw; considered a famine food. Leaves rich in calcium, carotene, and vit. C; astringent and slightly purgative. Sauropus androgynus; Chekkurmanis, Star gooseberry,Tender shoots and leaves used as vegetable. Rich in protein, carbohydrate, fat, fibre, carotene, vit. C, thiamine, riboflavin, niacin, and minerals. Momordica dioica; Spine gourd, Kakrol,Green fruits, rich in proteins, used for curing ulcers, piles, sores, obstruction of liver & spleen, cough, digestive problems and diabetes and Seeds used for chest problems and to stimulate urinary discharge. M. balsamina; Balsam Apple, Green fruits rich in vit. A, C, Fe and Ca and Plant's infusion used as anti-emetics, for stomach/intestinal complaints and diabetes. Basella alba (green), B. alba var. rubra (red); Indian spinach, Poi,Edible parts: Tender shoots/leaves/stem used as vegetable, soups and stews,Used in digestive disorders and contain antiviral substances and Sap of mature fruit used as a colouring agent in pastries and sweets. Diplazium esculentum; Lungru,Most commonly consumed fern, quite tasty, giving it the name "vegetable” and Young fronds, rich in iron, manganese and zinc, eaten as salad, vegetable, or pickle. Nasturtium officinale; Watercress, Edible parts: tender shoots or leaves used in soups, salad or as a garnish,Leaves exceptionally rich in vitamin C, folic acid, ascorbic acid and minerals, especially iron and Used as a detoxifier, antiscorbutic, diuretic and stimulant. Moringa oleifera; Drumsticks, Horse Radish tree,Mineral packed (calcium, phosphorus, and iron) perennial vegetable, rich in vit. A and C and Leaves, flowers and immature pods used in various vegetable dishes, curries, pickle, and as fresh mesocarp powder. Sesbania grandiflora; Agathi,Tender leaves, fruit, and flowers eaten as vegetable, curries or salad,Diuretic, aperient, emetic, laxative, febrifuge and tonic and Remedy for bruises, catarrh, dysentery, fever, headache, sores, smallpox, sore throat, stomatitis and night blindness. Solanum indicum; Bush tomato, Indian nightshade,Half ripe fruits used in preparation of curries, pastes or pickles; leaves used as vegetable and Fruits digestive and eaten to cure dysentery, malaria and gastritis. Trichosanthes dioica; Pointed gourd,Edible parts: Immature fruits and leaves used as vegetable, in soup, stew, curry, sweet, or fried and Used for overcoming constipation, fever, skin infections, and wounds and also Improves appetite and digestion. Carissa carandas; Karonda,Fruits sour, astringent, rich in iron, vit. C; used as pickles, chutney and Fruits antiscorbutic, useful to cure anaemia,Ripe fruit sweet, cooling, appetizer; useful in anorexia, burning sensation, skin diseases and scabies. Cordia myxa; Lasora, Indian cherry,Unripe fruits eaten as vegetable, pickles while ripe fruits used in making country liquor and Fruits useful in gastric problems, ulcer, leprosy, skin diseases, dry cough, bronchitis, chronic fever, and arthritis. Sechium edule; Chayote, choko,Fruits rich in amino acids and used as vegetable and snacks and Infusion of leaves used in treatment of arteriosclerosis, hypertension and to dissolve kidney stones.

97

Himachal Pradesh is a treasure house of traditional, locally adapted Indigenous vegetables, which are mostly underexploited.There are several lesser –known plant species, which have tremendous potential to be used as vegetables and they do not require high input technology and can thrive well on marginal and sub marginal lands and therefore, could be exploited for meeting the protein requirement of the predominantly vegetarian population of the country. Moreover vegetables greens like amaranth and chenopods possess of the very high protein along with higher content of lysine and essential amino acids. Increased use of these greens of high nutritive value could be great significance towards solving the problem of malnutrition, to some extent. Since IVs could help undercut the food insecurity at the household level, therefore there is need to promote their conservation, production, processing and utilization. (Kalia et al., 2007).

MARKET POTENTIAL

There is growing interest worldwide in, how farmers can benefit from emerging market opportunities, particularly in how they can access complex value chains associated with changes in the global agricultural economy

ØMarket access is seen as an opportunity both to reduce poverty and contribute to in situ conservation.

ØHeritage marketing' of superior selections of UUV is also helping to link small-scale farmers and traders with growing urban markets.

ØCommodity chains' are being established that generate new and sometimes lucrative income opportunities for poor farming households in rural, peri-urban, and urban settings and thus alleviating poverty.

ØUnderutilized vegetables and fruits offer huge potential to prepare various value- added products. These products are nutritious and high in fiber and antioxidants.

ØWith proper awareness on benefits of processed products and market promotion the demand for underutilized fruit/vegetable products, market share, and profits could be increased.

ØDemand for high value agricultural products is expected to grow faster in domestic , regional and export markets in Asia, Africa, and Latin America Access to these markets is also likely to lead to greater poverty reduction and conservation through use among smallholder producers of underutilized products.

98

FUTURE STRATEGIES:

There are several strategic factors that need to be taken into account if we are to successfully promote underutilized species and, at the same time, ensure that benefits are equally shared among community members. These include:

vFocusing on local values, indigenous knowledge and uses: such an approach will strengthen the link between diversity and sustainable uses and is important in considering marketability.

vRecognizing underutilized species as a public good to ensure the continued availability and accessibility of plant genetic material to present and future generations.

vFocus on groups of species as models through case-study approaches to make the best use of limited resources and facilitate for scaling-up and mainstreaming results.

vPromote cooperation among stakeholder groups and create national, regional and international synergies: this is not an option but a necessity, isolated efforts and success stories need to be linked and disseminated.

vAnalyze and enhance demand using market-oriented strategies: such an approach will create sustainable markets and reduce the risk of over-estimating economic potential.

vEmpower rural poor and strengthen their capacity to negotiate with the private sector and government: such interventions will ensure that the poor and underprivileged receive their rightful share of the benefits resulting from our promotion process. This is an important part of the livelihood approach and essential because many underutilized species are cultivated in poor areas where they represent one of the few - if not the only - asset of the local community.

vMainstream gender-sensitive approaches in management and use: these will allow groups like women - who are too often marginalized - to enhance their capacity to manage, conserve and use underutilized species in a sustainable way and - in doing so - strengthen their economic status.

vInter-disciplinary work: such an approach is critical if the opportunities of underutilized species - including nutritional, economic and social aspects - are to be tapped at all levels.

99

CONCLUSION

vNeed to broaden the range of plants species utilized by man.

vGlobal awareness is required not only amongst the researchers but equally among the planners, policy makers, growers and users all over the world.

vSpecific exploration programmes to collect genetic variability, conserve it and utilized for development of improved cultivars.

vPublic awareness drives should be carried out in rural area to educate people about the nutritional value of the niche based UUVs and their probable role in eradicating poverty, hunger and malnutrition.

vPopularization of potential and economics of UUVs.

vCharacterization and documentation of germplasm.

vDeveloping infrastructure for processing the product as wel as their marketing.

References:

Chadha, M.L.2009. Indigenous Vegetables of India with Potentials for Improving Livelihood. ISHS Acta Horticulturae 806: pp 579-585.

Engle, Liwayway M. and Faustino, Flordeliza C. 2007. Conserving the Indigenous Vegetable Germplasm of Southeast Asia. AVRDC, Acta Hort. 752. ISHS . pp 55-59.

Gautam, P.L. and Singh, A.K. (1998) Agro-Biodiversity and Intellectual Property Rights (IPR) Related Issues. Indian Journal of Plant Genetic Resources 11(2), 129–151.

Jaenicke, H and Hoschle-Zeledon, I. (eds.) 2006. Strategic Framework for Research And Development of Underutilized Plant Species with Special Reference to Asia, The Pecific And Sub- Saharan Africa. International Centre for Underutilized Crops (ICUC), Colombo, Sri Lanka and Global Facilitation Unit for Underutilized Species (GFU), Rome ,Italy.

Kalia Pritam, Sharma Akhilesh, Singh Sharda and Singh Yudhvir.2007. Locally Adapted Indigenous Vegetables of Himachal Pradesh and Their Role in Alleviating Poverty, Hunger and Malnutrition. Acta Hort. 752, ISHS :239-242.

Sehgal, J.L., Mandal, D K., Mandal, C. and Vadivelun, S. 1992. Agro-ecological Regions of India. Tech. Bull. No.24.NBSS &LUP(ICAR).New Delhi.

100

Off-season Tomato Production in North Western Himalayas under Changing Climate

Shiv Pratap Singh

Department of Vegetable ScienceDr YS Parmar University of Horticulture and Forestry, Nauni Solan - 173 230

Tomato is one of the most popular vegetables grown in north western Himalayas. In the mid hills of north western Himalayas it is usually grown during the summer months when in the rest of the tropical parts of the country the temperature shoots up very high making tomato cultivation difficult. During this period tomato grown in the mid hills of north western Himalayas fetches good price due to the off-season advantage in the adjoining plains where this crop is in shortage during this period. Tomato thrives best between 1-30°C and is neither tolerant to frost, nor to waterlogged condition. The optimum range of temperature is 20-24°C, mean temperatures below 16°C and above 27°C are not desirable. Soil which is well drained, fairly fertile, rich in organic matter with a fair water holding capacity is ideal. The crop performs well in soil having pH 6.0-7.0 and is moderately tolerant to acid soil (pH 5.5). The changing climate due to global warming is effecting the off-season tomato production in the hills. The temperature in the mid hills is increasing which in-turn is affecting the quality as well as the yield of tomato thereby putting a lot of impact on the socio-economic life of the farmers living here, as majority of farmers in mid hills of western Himalayas rely on tomato and fetch remunerative returns from this crop.

Impact of changing climate on tomato production in Western Himalayas

Changing climate has to some extent changed the summer temperature in mid hills and it has increased slightly in comparison to past decades, which has greatly affected the fruit setting and flowering in tomato. The various factors like temperature (both day and night), humidity, rainfall, light intensity etc greatly reduce the tomato yield if they are not in normal range during the crop growing season (Abdulla and Verkert, 1968). At higher temperature, the probability of floral abscission is high after anthesis (Iwahori, 1967). High day and night temperatures above 32°C and 21°C, respectively, are reported as limiting factors for fruit-set due to an impaired complex of physiological process in the pistil, which results in floral or fruit abscission ( Picken, 1984). High temperature associated with high night temperature during summer affects fruit-set of tomatoes in the country. Most of the regions in mid hills rely on monsoon for irrigation and only limited areas have some

irrigation facilities as a result due to erratic behaviour of the climate the crop gets exposed to water logged and drought stress conditions. The water logged conditions makes the crop more susceptible to various fungal pathogens and insect pests whereas the drought conditions lead to impaired plant growth and reduced yields. Thus due to changing climate and drift in average temperature to higher side have made many areas at low altitude marginal for successful off-season tomato cultivation during summer months.

Strategies for mitigating the effects of climate change for successful cultivation of tomato in North western Himalayas

Use of plant growth regulators

Use of plant growth regulators in tomato has been found beneficial for yield, quality, earliness, fruit setting under low and high temperatures and to develop resistance to diseases like TLCV etc. Growth regulators activate the root growth, increase fruit set and yield. They also effect the physiological process hasten maturity and help in getting better quality fruits. Foliar application of GA at 10 ppm, 3

NAA 1000 ppm, PCPA (Parachloro-phenoxy acetic-acid) at 50 ppm, 2,4-D at 0.5 ppm or cytozyme at 1.25% is reported to increase the fruit yield. Spraying of PCPA at 50 ppm, IAA 50 ppm or Borax 1% gave better fruit set in higher temperature. The foliar application of PCPA 50-100 ppm at the flowering stage increases the fruit set at low and high temperatures.

Use of grafting techniques

Grafting tomato onto flood and disease-resistant rootstock is a potential technology to overcome the abiotic and biotic problems. This technology can be used for successful cultivation of tomato in adverse climatic conditions. High yielding and heat-resistant tomato scions like Apollo and CL 5915 and flood and bacterial wilt-resistant rootstocks like H7996 (tomato) and EG203 (eggplant) have been found to be superior. Provision of rain shelter to grafted tomato increased the yield by 340% over grafted plants grown in open field. Grafting and rain shelter significantly improved the yields of CL5915 and Apollo (Claritap et al., 2004).

Development of new climate resilient tomato varieties/Hybrids

Climate change leads to depression in yield of the various crops due to unfavourable environmental conditions posed by it; tomato is no exception to the climate change and its off-season cultivation is becoming difficult due to erratic climatic conditions being faced during its growth period in the hills. Thus there is need to develop new technologies and climate-resilient varieties/ hybrids of tomato which are tolerant to heat, cold stress and resistant to water logged conditions.

102

Protected cultivation

Protected cultivation though costly can be adapted to mitigate the climate change. Growing tomato in naturally ventilated polyhouse with fan pad system and shading net is widely being used in mid hills of Western Himalayas. Farmers are also getting subsidy for building of the polyhouse for successful tomato cultivation. The climate inside polyhouse can be regulated by cooling the polyhouse with fan pad system and by obstructing the sun light with the help of shading nets for specific time during day. The additional advantage of the polyhouse grown tomato is that the produce is of high quality and free from excessive pesticides as very limited sprays are done in polyhouse grown vegetables. Though fully climate controlled polyhouses can be made which will make the year round cultivation of tomato feasible but the cost of the construction and operation of such polyhouses is very high which makes them un-economical therefore more emphasis is given only on the cultivation of tomato in partial climate controlled naturally ventilated polyhouses.

Development of new improvised cultural practices

Climate change creates lot of strain on natural resources like water by making the availability of water uneven during the growing period as a result sometimes it is in plenty, while there are occasions when there is water drought conditions. The western Himalayan region is also experiencing the erratic rains due to global climate change as a result there is a need to employ improvised irrigation methods like sprinkler and drip irrigation etc. which minimize the use of water and increase the water use efficiency. The technology of growing tomatoes on raised beds and use of improvised training system comprising of iron wire and iron angle can help the crop to perform better during the rainy season as the off-season crop is greatly affected by the water logging conditions during this particular time of the year.

Reference

Abdulla, A.A., and Verkerk, K. 1968. Growth flowering and fruit-set of the tomato at higher temperature. Neth. J. Agric. Sci.16. 71-76.

Iwahori 1967. Auxin of tomato fruit set at different stages of its development with a special reference to high temperature injuries. Plant and Cell Physiol. 8. 15-22.

Picken, A.J.F. 1984. A Review of pollination and fruit set in the tomato (Lycopersicon esculentum Mill). Journal of Horticultural Science. 55: 1-13.

Claritap Aganon, Lun G Mateo, Dennis Cacho, Anacleto Bala J R and Teotimom Aganon. 2004. Philippine Journal of Crop Science. 27(2): 3-9

103

Influence of Climate Change in Capsicum Production

Santosh Kumari

Department of Vegetable ScienceDr YS Parmar University of Horticulture & Forestry, Nauni, Solan-173230 HP

All vegetable crops are sensitive to temperature and most have specific temperature requirements for development of optimum yield and quality. Climate change will impact capsicum in following ways:

§Increase in pollination failures under higher temperature during flowering

§Floral abortion will occur under higher temperature

§Increased heat stress will adversely affect fruit size and quality of the fruit

§Cultivars are currently not as adaptable to higher or more variable temperatures as they were before

§Increased incidence of physiological disorders like blossom end rot and sun scald

§Increased incidence of insect pests under higher temperature

§Increased risk of spread and proliferation of soil borne diseases like leaf blight and fruit rot, as a result of more intense rainfall events coupled with warmer temperatures

§An increasing incidence of out of season and extreme rainfall events will affect the timing of cultural practices and negative effects on yield and product quality

§Increasing temperatures will impact greenhouse crop production, especially production in sub-tropical regions, where summer temperatures is high and restrict production to the cooler months of the year

§In temperate areas there will be less effect and sowing time can adjusted accordingly.

§More irrigational water will be required because of higher evaporative demand.

Mitigation

§Sowing dates of the crop can be adjusted according to changing temperature

§Selection of the cultivars which are more adaptable to a changing and variable climate

§Crop should be grown under polyhouses to avoid losses due to unfavourable

climatic conditions like high temperature, heavy rains, strong winds and hailstones etc.

§Integrated Pest and Disease Management (IPDM) will be an important tool to adapt to changing climate

§Mulching with different mulching materials will help in reducing the incidence of soil born diseases like leaf blight and fruit rot

§Scientists have to breed the cultivars, suitable to grow under changing temperature, resistant to insect, pest and diseases

To cope up with the effects of climate change we have to follow good production technology in capsicum and also to increase the yield and for good quality of the produce.

Sweet pepper is botanically known as Capsicum annuum L. It belongs to family Solanaceae. South America, especially Brazil is thought to be the original home. It is grown in Central and South America, Peru, Bolivia, Costa Rica, Mexico and in almost all European countries. In India, it is cultivated commercially in Tamil Nadu, Karnataka, Himachal Pradesh and in some parts of Uttar Pradesh. In Northern India it is also known as 'Simla Mirch' and is an important crop grown expensively in mid hills of Himachal Pradesh to supply to plains. Sweet pepper is rich in vitamin A and C. Fruits may be eaten cooked or raw, sliced in salads.

Cultivars: There are several cultivars of bell shaped, non-pungent, mild, thick fleshed sweet peppers or simla mirch. The important cultivars are California Wonder, Solan Bharpur, Yolo Wonder, King of North, Early Giant, World Beater, Chinese Giant, Arka Gaurav and Arka Mohini. Important hybrids are Bharat, Indira, Hira, Solan Hybrid-1 and Solan Hybrid-2 etc.

Soil: Sweet pepper can grow in almost all types of soil, but well drained clay loam soil is considered as ideal for cultivation of sweet pepper. It can withstand acidity to some extent. For commercial cultivation, levelled and raised beds were found more suitable than sunken beds. On sandy loam soil, crop can successfully be grown provided manuring is done heavily and the crop is irrigated properly and timely. The sweet pepper plant produced best when soil pH was 6-6.5.

0 0Climate: Sweet pepper is a warm season crop. It requires 25 C day and 18 C night temperature for higher yield, fruit weight, length, girth, number of fruits per plant and pericarp thickness. Fruit development is found to be adversely affected at

0temperature of 37.8 C or above. High temperature and low humidity at the time of flowering increase the transpiration pull resulting in abscission of buds, flowers and small fruits (Cochran, 1936). High night temperature has found to be responsible for the higher capsaicin content (Ohta, 1962).

105

Raising of seedlings and transplanting: Seedlings are first raised in the nursery beds and then transplanted in the main fields. Normally, 6-8 nursery beds (300 x 100 x 15 cm) are sufficient for one hectare cultivation. Seeds should be sown in rows to get healthy seedlings. The seeds should be dressed with Thiram or Captan at the rate of 2g per kg of seeds before sowing to prevent seed born diseases. Seed rate of 750-900 g/ha (OP varieties) and 200-250 g/ha (hybrids) is required for one hectare cultivation. The seeds should be covered with a layer of FYM or soil manure mixture and irrigate everyday to maintain optimum soil moisture. In hills the sowing time for sweet pepper is March- April and in southern states October –November. The seedlings having 4-5 leaves should be transplanted. The nursery beds should be irrigated before lifting of seedlings. Transplanting is done in evening hours followed by irrigation. The seedlings are transplanted to the field in rows at a distance of 60 cm and plant to plant distance is kept 45 cm.

Manures and fertilizers: Application of balanced dose of fertilizers is necessary for proper growth and development of the plants. FYM-200-250 q/ha, CAN- 400 kg , SSP- 475 kg, MOP- 90 kg per hectare is applied in capsicum crop. Full dose of FYM, SSP, MOP and half dose of CAN should incorporated at the time of field preparation and remaining dose of CAN is applied in two split doses at one month interval after transplanting.

Irrigation: The first irrigation should be given just after transplanting. Later, the field should be irrigated as and when required. Optimum soil moisture should be maintained in the soil at the time of flowering, fruit set and fruit development.

Weed control: Weeds can be removed manually by hand. Two weedings 30 and 60 days after planting are sufficient. Pre-plant incorporation of weedicides like Fluchloralin @0.5-1.0 kg/ha and Alachlor @2.5 kg/ha can also be done to control the weeds.

Harvesting: The sweet pepper fruits are usually picked while they are still green in colour, firm and crispy. Yield varies from 300-400 q/ha.

Capsicum production under greenhouse: Growing capsicum under greenhouses is proving to be very remunerative venture to greenhouse growers as it fetches maximum returns in the market. Coloured varieties of sweet pepper like red and yellow are being grown by farmers and sold in the markets at distant places. Agro techniques to grow capsicum under greenhouse are as under

§In mid hills of Himachal Pradesh, two crops of capsicum can be taken, one spring summer crop (January to June) and another autumn winter crop (July to December).

§In capsicum generally those varieties and hybrids are grown which give

106

maximum productivity with good shape and size of fruits and suits to year round production. These cultivars should have longer harvest duration. Indira (green), Orebelle (yellow), Bomby (red) are suitable varieties for cultivation under polyhouse.

§To raise nursery, seeds are sown in well prepared nursery beds or plastic trays having uniform growing media comprising of soil and compost/FYM. The seedlings are ready after 4-5 weeks for transplanting depending upon the season of growing. The transplanting of seedlings after their hardening is done in an existing greenhouse in the evenings for the better establishment of plants in a growing media comprising of soil, FYM/compost and sand (2:1:1). Closer spacing of 45 x 30 cm is kept in polyhouse.

§Training and pruning is an essential operation in greenhouse crops for better management and providing uniform light to the plants. It also helps in efficient utilization of resource and greenhouse environment by crops. In capsicum, two stem and four stem training system is followed.

o§Temperature between 18-27 C and relative humidity ranging from 60-80 %

with more CO (900-1200 ppm) is considered ideal for good quality fruit 2

production.

§Irrigation is done every day in summers and every third day in winters by drip irrigation.

§Before transplanting, N, P and K are incorporated in soil @ 50 kg/ha. Fertigation is done using water soluble fertilizers like polyfeed @ 150 kg/ha (19:19:19) twice in a week and is started from third week after transplanting up to 15 days before last harvest.

§When fruits start attaining proper colour may be harvested and firm and crispy. For long distance markets the fruits should be packed in good containers to avoid any damage in transit and storage. Generally harvesting starts 55 days after transplanting in most of the varieties. A well managed crop of bell pepper under greenhouse conditions is expected to give a yield of

210-13 kg/m .

References:

Bose, T K, Som M G and Kabir J.Vegetable Crops. Naya Prokash Calcutta.

Chaudhary A K, Fageria M S and Arya P S. Vegetable Crops Production Technology. Kalyani Publishers.

107

Efficient Irrigation Management Practices in Vegetable Crops

JN Raina

Department of Soil Science &Water ManagementDr YS Parmar University of Horticulture & Forestry Nauni, Solan 173230

When, how much and how to irrigate are important questions for farmers/growers, mainly because of the increasing energy costs and lack of adequate water resources. The rational management of irrigation is, therefore, an indispensable process in irrigated crop production. Many interacting factors determine the frequency of application and the amount of water to be applied. Some of these factors include: the plant's inherent water requirements based on species; the climate of the region (macro climate) and the environment around the specific area (micro climate); the season of year; the type of water delivery (irrigation) system; and the desire or necessity to conserve water. The present paper embodies information on irrigation water management approaches, advantages of hi-tech irrigation systems and future needs related to efficient water management in vegetable crops

The conventional method of irrigation (flooding, furrow, flat bed, corrugation, boarder, ring etc.) revolves around the concept of replenishing the moisture level to field capacity (FC) after 50 to 60% depletion. The plants actually use only 40-50% of the water delivered through these methods. The low efficiencies are attributed mainly to the conveyance losses resulting from seepage, percolation and evaporation. On the other hand, drip irrigation system is for efficient (Table1) owing to precise and direct application of water in the root zone. (Raina 2000; 2002)

Table 1 Irrigation efficiencies (%) under different methods of irrigation

Drip irrigation is a technique in which water is applied in small and precise amount at frequent intervals, directly near the root zone, through emitting devices via

Irrigation method efficiency Methods of irrigation

Surface Sprinkler Drip

Conveyance efficiency 40-50 (Canal) 60-70 (well)

100 100

Application efficiency 60-70 70-80 90 Overall efficiency 30-35 50-60 80-90

a network of PVC/HDPE mains, sub mains, filtration unit, control valves and LLDPE laterals. The technology has the greatest potential where water is either very expensive or scarce or the soils are coarse textured. The technology assumes a special significance in Himalayan regions, which are endowed with undulating topography, are difficult to level and having higher runoff rates. Micro-irrigation was practiced in India through indigenous methods such as bamboo pipes, perforated clay pipes and pitcher/porous cup irrigation. To promote the concept of drip-irrigation, efforts have been made at the research level by Indian Council of Agriculture Research, Agricultural Universities, and National Committee on Use of Plastics in Agriculture, Ministry of Water Resources and Drip Manufacturing Association. Drip-irrigation also enables the use of fertilizers, pesticides and other soluble chemicals along with the irrigation water more economically .Different components of drip system are shown in figure1

Advantages of Drip Irrigation: Every irrigation method has its own merits and demerits. For the drip system, the advantages, however, far outweigh the disadvantages.

·Water Saving: Due to partial wetting of the soil volume, reduced surface evaporation, decreased runoff and controlled deep percolation losses, the water use efficiency under drip irrigation is markedly higher than traditional flood or furrow irrigation. With drip irrigation water savings to the extent of 52 % in garlic; 50.0 to 70.0% in pea and tomato: 37% in cauliflower and 30% in okra has been reported. (Sivanappan and Padamkumari 1980; Pawar et al., 1993; Raina et al 1998, 1999). The comparative results on drip and surface irrigation in some vegetable crops are cited in table 2 and 3.

Table 2: Water use and yield under two methods of irrigation.

Table 3: Effect of irrigation methods on yield and water use efficiency of garlic

Source; Sivanappan and Padamkumari 1980

Crop Water use (cm) Yield Q ha-1

Surface Drip Surface Drip Tomato 49.8 10.7 61.9 88.7 Okra

53.5

8.6

100.0

113.2

Irrigation

Method

Bulb yield

(Mg ha-1)

Clove No bulb-1 Seasonal Cu

(cm)

Water use

efficiency

Kg/ha-cm Surface

8.61

31.0

63.1

136

Drip

8.68

31.9

35.1

247

Source: Pawar et al 1993

109

Irrigation water requirement under drip has reported to be for lower than conventional surface irrigation resulting in more than 50% savings in water besides improving the fruit yield by 40 per cent (Table4)

Table 4: Irrigation requirement of tomato crop under surface and drip irrigation methods

· Enhanced plant Growth and Yield: Slow and frequent watering eliminates wide fluctuations in soil moisture content resulting in better growth and yield. Application of mulch in conjunction with drip system proved more beneficial in saving the irrigation water and improving the yield. Raina et al (1988, 1999) tried drip irrigation levels at 'V', 0.8 V, 0.6 V i.e. at 100, 80 and 60% ETC both with and without mulch and compared the treatments with conventional surface irrigation (Table 5). Drip irrigation increased pea and tomato yield by 30-40% over surface irrigation. Application of mulch further raised the yield both under drip and surface irrigation. The higher yields under mulch may be attributed to the moderation in soil thermal conditions, moisture conservation besides considerable weed control.

Table-5: Effect of different treatment on crop yield of tomato and pea (q/ha)

Year Amount of irrigation applied

(cm)

Water

savings by

drip (%)

Increase in

fruit yield by

drip (%)

Surface

Drip

1987

77

40

48

32

1988

56

24

57

49

Average

67

32

53

40

Source: Bafna et al. 1993

Treatment Tomato

Pooled Pea

Pooled

1996

1997

1995-96

1996-97

T1(DV)

134.1

156.5

145.3

87.7

91.4

89.5

T2(0.8V)

152.8

179.8

166.3

76.4

87.7

82.1

T3(0.60 DV)

125.8

146.3

135.9

60.6

72.0

66.3

T4(S)

110.5

128.4

119.5

57.6

62.2

59.9

T5(DV+M)

206.4

192.2

199.3

104.8

105.8

105.4

T6(0.8 DV+M) 238.7 226.4 232.5 82.4 94.5 88.4

T7 (0.6 DV+M) 208.5 182.4 195.5 68.2 82.4 75.3

T8 (S+M) 159.6 151.2 155.4 62.5 70.1 66.3

CD0.05 17.5 20.2 12.5 10.5

110

·Saving in labour and Energy: There is a considerable saving in labour as the well designed system needs labour only to start and stop the system. Because of high irrigation efficiency much time is not required to supply the desired quantity of water, thus, it also saves energy.

Weed Control: Due to partial wetting of soil, weed infestation is very less in comparison to other methods of irrigation.

Most Suitable for poor Soils: Very light (sandy) soils are difficult to irrigate due to deep percolation of water. Like- wise, very heavy soils are difficult to irrigate, even by sprinkler methods because of low infiltration rates.

Salinity Hazards: Less moisture content due to frequent irrigations and lesser water requirement over the surface method keep saline concentration below the detrimental levels.

Soil Erosion: There is no soil erosion due to drip irrigation.

Fertilizer use efficiency: Because of reduced loss of nutrients through leaching, runoff and volatization and also local placement in the root zone, FUE is considerably improved.

Disease incidence: Easy installation, minimum tillage and incidence of diseases and pests are added advantages of drip irrigation.

Constraints of drip system: There is no second opinion about the immense potential and prospects of drip system. But, there are some constraints listed below, which need to be solved by multi- pronged effort:

ØIt requires high initial investment.

ØFrequent clogging of drippers. The clogging could be due to algae, salt accumulation or foreign particles.

Ø Non availability of technical manpower.

ØInadequacy of technical input for efficient management of drip irrigation system.

ØIt is not suited for frost protection or for cooling during periods of hot weather.

ØThey are not suited for supplemented irrigation of large areas.

Ø Availability of components and cost of spares.

111

Future Needs: With the ever increasing demand for water in the domestic and industrial sector, the allocation of water for agriculture is likely to decline considerably. This calls for judicious use of water adopting strictly the recommended irrigation schedules and efficient water injection systems such as drip/sprinkler. Application of irrigation water through high tech systems such as sprinkler/ drip is an integral component of protected cultivation. Irrigation water requirement is expected to vary markedly for different vegetable crops being raised under open and polyhouse conditions in different parts of the country and also with the type of irrigation system being used. So for, scanty information on these aspects has been generated and documented. There is thus, a need to determine drip/ sprinkler irrigation water requirement and their schedules for different vegetable crops being raised in different agro-climatic zones of the country. Crop coefficient values for different growth stages of different vegetable crops also need to be documented for specific agro climatic conditions. Such values are of utmost importance to compute tentative water requirement of corps using various mathematical models. There is also a need to popularize the high tech irrigation systems among farmers and growers through demonstrations pin pointing the advantages of such systems related to water savings and improvement in yield and quality of flowers.

References:

Bafna, A.M. Dafatdar,S.Y. Khade,K.K. and R.S.Rathor (1993) Utilization of nitrogen and water by tomato under drip irrigation J. Water Managment. (1): 6-9.

Raina, J.N. and B.C. Thakur and A. R. Bhandri (1998) Effect of drip irrigation and plastic mulch on yield, water use efficiency and benefit-cost ratio of Pea cultivation. J. Indian Society Soil Science 46: (4) 562-67.

Raina, J.N., Thakur, B.C. and M.L. Verma (1999) Effect of drip irrigation and polyethylene mulch on yield, quality and water use efficiency of tomato. (Lycopersicon esculentum) Indian J. Agric. Sci. 69 (6): 430-33.

Raina, J.N. (2000) Drip irrigation and fertigation in vegetable crops. : HorticultureTechnology (Eds.) V.K. Sharma and K.C. Azad. Deep and Deep Publications, New Delhi,Vol. II: pp339-346

Raina, J.N. (2002) Drip irrigation and fertigation: Prospects and retrospect's in temperate fruit production: In: Enhancement of temperate fruit production in changing climate (Eds.) K.K. Jindal and D.R. Gautam Publn. UHF, Solan pp

Sivanappan, P.K. and O. Padamkumari (1987) Drip irrigation Keerthi Pub. House Pvt.Ltd. Coimbatore.

112

Impact of Climate Change on Vegetable Crop Production vis a vis Mitigation and Adaptation Strategies

Satish Kumar Bhardwaj

Department of Environmental ScienceDr YS Parmar University of Horticulture & Forestry, Nauni- 173230, Solan, HP

Climate change has been recognized as the single most challenge that humans and the mother Earth is facing today. The problems would further aggravate in the years to come if no corrective measures are taken. This change has happened due to years of over exploitation of natural resources, faulty practices in agriculture and industries. The change in climate is mainly caused by increasing concentration of the Green House Gases in the atmosphere. In 1980s, scientific evidences linking GHGs emission due to human activities causing global climate change, started to concern everybody. Subsequently, United Nations General Assembly in 1992 formed Intergovernmental Negotiating Committee for Framework Convention on Climate Change (UNFCCC) which finally adopted the framework for addressing climate change concerns.

Climate is defined as the “average weather”, or more precisely, as the statistical description of the weather in terms of the mean and variability of relevant quantities over periods of several decades (typically three decades as defined by WMO). Climate change according to Inter Governmental Panel on Climate Change (IPCC) refers to 'a change in the state of the climate that can be identified (using statistical tests) by changes in the mean and/or the variability of its properties that persist for an extended period, typically decades or longer. However, UNFCCC in its Article 1 defines “climate change” as “a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods”. The UNFCCC thus makes a distinction between “climate change” attributable to human activities altering the atmospheric composition, and “climate variability” attributable to natural causes.

Climate Change Situation

Climate of the planet earth is always in a state of change as a natural process influenced by both natural variability and induced environmental changes due to anthropogenic reasons. Natural causes include continental drift, volcanoes, earth's tilt, solar output variations and ocean current while human causes are green house gas emissions and land use change etc. However, the reason for worry is that climate change is taking place at a much faster rate than expected by the human interference.

The IPCC has been publishing periodic assessment reports on atmospheric carbon concentration and its likely impact on the environment. According to this International scientific body the CO concentration has increased from a value of 2

about 280 ppm during pre-industrial era to 393 ppm in 2010. Similarly, the global atmospheric concentration of methane and nitrous oxides and other important GHGs, has also increased considerably. Accordingly to the IPCC, this has resulted

o 0in warming of the climate system by 0.74 C ± 18 C between 1906 and 2005. Global average sea level rose at an average rate of 1.8 mm per year over 1961-2003. The

oIPCC has projected a temperature increase in the range 1.1 to 6.4 C by the end of this century. For South Asian including Indian region, the IPCC has projected 0.5 to

o o o1.2 C rise in temperature by 2020, 0.88 to 3.16 C by 2050 and 1.56 to 5.44 C by 2080, depending on the scenario of future development (IPCC 2007). Climate change is projected to increase the global temperatures, cause variations in rainfall, increase the frequency of extreme events such as heat, cold waves, frost days, droughts, floods, etc with immense impact on agriculture sector.

Influence of Elevated CO2

In climate change impact studies CO concentration is important as it is the 2

principal driver of climate change. In studying the impact of climate change on gardens, as with agriculture, forestry and nature conservation, carbon dioxide itself has a significant impact by its involvement in photosynthesis. Plants with C3 photosynthetic metabolism benefit due to increase in atmospheric CO 2

concentrations and will be able to accumulate more biomass. Increases in atmospheric CO concentration affect how plants photosynthesise, resulting in 2

increases in plant water use efficiency, enhanced photosynthetic capacity and increased growth. Increased CO has been implicated in 'vegetation thickening' 2

which affects plant community structure and function. Controlled environment studies indicated that elevated CO at 550 ppm improved the bulb size and yield of 2

onion. Tomato plants grown at 550 ppm CO environment produced 24% more 2

fruits. Elevated CO is reported not only to improve the yield but also alters the 2

quality of the produce. The quality (carotene, starch and glucose content) and tuber yield of sweet potatoes increased in elevated CO conditions. Increased CO can also 2 2

lead to increased Carbon: Nitrogen ratios in the leaves of plants or in other aspects of leaf chemistry, possibly changing herbivore nutrition.

Increased concentration of atmospheric carbon dioxide stimulates crop growth by the so called “Carbon fertilization” effect (Rogers and Dahlman, 1993). A doubling of the atmospheric CO concentration increases plant growth and 2

marketable yield by 30-40% in C3 plants (Kimball, 1983). Most plants growing in

114

enhanced CO exhibit increased rates of net photosynthesis brought about by 2

increased CO availability at the chloroplasts and reduced photorespiration resulting 2

from an increased ratio of O to CO 2 2

Effect of Rise in Temperature

The positive effect of elevated CO might be offset by the adverse effect of 2

associated global warming. Increases in temperature raise the rate of many physiological processes such as photosynthesis in plants, to an upper limit. Extreme temperatures can be harmful when beyond the physiological limits of a plant. Even though elevated CO will cause positive impacts, these may be nullified by increased 2

temperature and less water availability resulting decreased production under the current level of management. Temperature affects vegetable crops in several ways by influencing crop duration, flowering, fruit growth, ripening and quality.

Weather conditions during flowering and pollination and subsequent fruit growth determine the production quantity and quality. It has been reported that the increased temperature beyond optimum range caused delayed curd initiation in

0cauliflower. Temperature above 30 C induced maximum flower and fruit drop and high temperatures after pollen release decreased fruit set and fruit yield in tomato.

0Temperature above 40 C reduced the bulb size in onion. In beans high temperature delay flowering because the enhance short day photoperiod.

Low temperatures during extreme winters also influence vegetable crop production. For example cold wave during December 2002 and January 2003 caused considerable damage to brinjal, tomato and potato crops. In cucumber sex expression is affected with low temperatures leading to more female flowers and high temperatures lead to more male flowers.

Effects of Water

In some areas rainfall has increased in the last century, while some areas have dried. As water supply is critical for plant growth, it plays a key role in determining the distribution of plants. Changes in precipitation are predicted to be less consistent than for temperature and more variable between regions, with predictions for some areas to become much wetter, and some much drier. Unprecedented changes in the rainfall pattern leading to drought like situation in some areas could have serious implications on crop production in general and in small and marginal farms in particular.

Changes in Distributions of Plants

If climatic factors such as precipitation and temperature change in a region beyond the tolerance of a species phenotypic plasticity, then distribution changes of

115

the species may be inevitable (Lynch and Lande 1993). There is already strong evidence that plant species are shifting their ranges in altitude and latitude as a response to changing regional climates (Permeson and Yohe 2003, Walther et al. 2002). When compared to the reported past migration rates of plant species, the rapid pace of current change has the potential to not only alter species distributions, but also render many species as unable to follow the climate to which they are adapted. The environmental conditions required by some species, such as those in alpine regions may disappear altogether. The result of these changes is likely to be a rapid increase in extinction risk (Thomas et al. 2004). Changes in the suitability of a habitat for a species drive distributional changes by not only changing the area that a species can physiologically tolerate, but how effectively it can compete with other plants within this area. Changes in community composition are therefore also an expected product of climate change.

Indirect Impacts of Climate Change

A pathogen or parasite may change its interactions with a plant, such as a pathogenic fungus becoming more common in an area where rainfall increases. Under the changing climate situations existing fungal pathogen, bacteria, viruses may cause more damage. Some of the minor pests may become major pests in future.

0Advancement in appearance of aphids by two weeks with increase in 1 C temperature reduced growing period for seed potato crop.

Impact of Climate Change on Agriculture

The environmental changes projected due to climate change are likely to increase the pressures on Indian agriculture, in addition to the on-going stresses of yield stagnation, land-use, competition for land, water and other resources, and globalization. Recent report of the IPCC and a few other global studies indicate a probability of 10-40% loss in crop production in India with increases in temperature by 2080-2100 (IPCC 2007). The year 2002 was a suitable example to show how Indian food grain production depends on rainfall of July and it was declared as all- India drought, as the rainfall deficiency was 19% against the long period average of the country and about 30% area was affected due to drought. The kharif food grains production was adversely affected by a steep fall of 19.1% due to all India drought during monsoon 2002. Similar was the case during all –India drought in 1979 and 1987 as well as during kharif season 2009 in Himachal Pradesh. It reveals that the occurrence of droughts and floods during the Southwest monsoon across the country affects foodgrains production to a greater extent.

Agricultural productivity is the ultimate determinant for the carrying capacity of the Earth. With present food grain production of about 1800 million tonnes, world is still short of required food supply by about 90 million tonnes every

116

year. Despite technologically advances like improved varieties, fertilizers, irrigation methods, biotechnology, etc; weather is still the key determining factor for agricultural productivity. The possible impacts of climate change on agriculture are:

i) Rise in temperature increases transpiration and in drier regions leads to water stress causing yield reduction. In India only about 40% area is irrigated and remaining 60% is rainfed. Even if we realize full irrigation potential in the country, nearly 50% area will still remain rainfed. Under such circumstances increase in temperatures and changes in rainfall patterns are likely to reduce agricultural productivity in rainfed areas.

ii) The climate change will probably lead to a decrease in crop productivity, but with important regional differences (McCarty et al., 2001). In tropical and sub-tropical regions like in India where the crops are already near the limit of their temperature tolerance, even a slight increase in temperature will result in drastic fall in crop productivity. However, crop productivity is expected to rise slightly in mid to high latitudes for mean temperature increases of upto

o3 C. Coupled with enhanced CO concentration, food productivity in these 2

oareas is expected to increase with rise in temperature up to 3 C and fall with further rise in temperature.

iii) The rate of development in plants increases with rise in temperature. A short life cycle, though less productive, can be beneficial for escaping drought and frost and late maturing cultivars could benefit from faster development rate. In colder regions, global warming could lead to lengthening of growth period and optimal assimilation at elevated temperate.

iv) Extreme events like droughts, floods, tropical cyclones, heavy precipitation and heat waves will negatively impact agricultural productions.

vi) The fertilizer use efficiency that ranges currently between 2 to 50% in India is likely to be reduced further with increasing temperatures. Greater fertilizer use to boost agricultural production will in turn lead to higher emission of greenhouse gases.

vii) Small changes in temperature and rainfall will have significant impact on quality of food grains, vegetables, tea, coffee and medicinal plants with resultant implications in domestic and external trade.

viii) Changes in temperature and humidity will also change pest population. New and aggressive pests including weeds are likely to invade our crops.

117

Adaptation to Climate Change

There have been several technologies which are already available and can be useful for reducing the impact of climate change. Development of adverse climate tolerant varieties may take more time but already known agronomic adaptations, crop management and input management practices can be used to reduce the climate related negative impacts on crop growth and production. Some of simple but effective adaptations strategies include change in the sowing date, use of efficient technologies like drip irrigation, soil and moisture conservations measures, fertilizers management through fertigation, change of crop/alternate crop, increase in input efficiency, pre and post harvest management of economic produce can not only minimize the losses but also increase the positive impacts of climate change. There is a lot of a scope to improve the institutional support systems such as weather based agro-advisory. Input delivery system, development of new land use patterns, community storage facilities for perishable produce of vegetable crops, community based natural resource conservation, training farmer for adopting appropriate technology to reduce the climate related stress on crops etc. All these measures can make the horticultural farmer more resilient to climate change.

Mitigation Measures

Most of the vegetables being annual crops do not have any carbon sequestration potential, the scope for reducing emissions in their cultivation is highly limited and moreover the information on these aspects is lacking. Resource conservation techniques and organic farming are the other mitigation measures which can be followed.

Research Thrusts

Some of the researchable issues include:

• Breeding vegetable hybrids and varieties tolerant to heat and drought stress

• Quantification of impacts of elevated temperature and CO on growth, 2

development, yield and quality of crops.

• Biotechnological approaches for multiple stress tolerance

• Development of suitable agronomic adaptation measures for reducing the adverse climate related production losses

• Development of crop simulation models for crops for enabling regional impact, adaptation and vulnerability analysis

• Identification and refinement of indigenous technological knowledge to meet the challenges of weather related aberrations

118

• Development of eco-friendly and water use efficient irrigation systems

• Development of eco-friendly and efficient fertilizer application systems

• Development of pre and post harvest produce storage systems which can meet the challenges of climate related risks

• Recycling/usage of vegetable biomass should be emphasized

Capacity Building

There is an urgent need to train the researchers, extension personnel, gardeners and farmers on climate change issues. Infrastructural development also needs to be taken to make the Indian agriculture resilient to climate change. More storage structures and training on making of value added products can augment the farm income to make farmer more resilient to adverse situations. Training also needs to be provided on eco-friendly adaptation technologies.

Conclusions

Currently, the world agriculture especially the vegetable production is passing through a difficult situation and faced with the challenge of food/nutritional security to meet the requirement for ever growing population. We have to produce more and more food from less and less land. The problem gets aggravated because of the growing biotic and abiotic stresses and decline in the quality of environment and along with the menace of increasing global warming caused by the green house gases. The succulent vegetable crops are highly sensitive to climatic conditions of heat, drought and flooding. Therefore, there is an urgent need to focus attention on studying the impacts of climate change on growth, development, yield and quality of crops. The focus should also be on development of adaptation technologies and quantify the mitigation potential of the crops. Elevated CO has positive effect 2

ranging from 24-51% on productivity of vegetable crops. However, rise in temperature affects crop duration, flowering, fruiting, fruit size and ripening of vegetable crops with reduced productivity and economic yield. Therefore, overall impact of climate change and global warming will depend on interaction effect of elevated CO and temperature rise. Development of new cultivars of crops tolerant to 2

high temperature, resistant to pests and diseases should be the main strategies to meet this challenge. Accurate impact analysis of global warming on vegetable crops is required to evolve adaptation measures and future strategies to cope with climate change and global warming.

119

References:

Fitter AH and Fitter RS. 2002. Rapid changes in flowering time in British plants. Science 296 (5573): 1689–91.

IPCC. 2007. Climate change 2007: Climate Change Impacts, Adaptation and Vulnerability.Summary for Policymakers. Intergovernmental Panel on Climate Change.

Kimball BA. 1983. Carbon dioxide and agricultural yield: an assemblage and analysis of 430 prior observations. Agron. J. 75: 779-88

Lynch M and Lande R. 1993. Evolution and extinction in response to environmental change. In Huey, Raymond B.; Kareiva, Peter M.; Kingsolver, Joel G. Biotic Interactions and Global Change. Sunderland, Mass: Sinauer Associates. pp. 234–250.

McCarty JJ, Canziani OF, Leary NA, Dokken DJ and White KS. 2001. Climate change 2001. Impacts ,adaptation and vulnerability. Contribution of Working Group II to the third Assessment Report of The IPCC. Cambridge University Press, Cambridge, UK.

Parmesan C and Yohe G. 2003. A globally coherent fingerprint of climate change impacts across natural systems. Nature 421 (6918): 37–42.

Rogers HH and Dahlman RC.1993.Crop responses to CO enrichment. 2

Vegetatio.104/105:117-31.

Thomas CD, Cameron A and Green RE. 2004. Extinction risk from climate change. Nature 427 (6970): 145–148.

120

New Pathological threats to Vegetable Crops and their Management under Changing Climatic Conditions

RC Sharma

Directorate of ResearchDr YS Parmar University of Horticulture & Forestry, Nauni, Solan173 230

The Impact of global climate change on vegetable crops has recently become a subject of increasing importance. Majority of the studies, however, confine their enquires to the biological and physical domains, concentrating mainly on representing the responses of vegetable crops to various changes in climate. Most of studies are dependent on the broad scale predictive ability of general circulation models on which they are based, reducing the utility of these models in fine scale studies at regional and local scale levels. There have been reductions in the intensity of snowfall as well as changes in the timing of snowfall. No discernible change in the intensity of rainfall has occurred. The temperature distribution has undergone a significant shift in addition to an overall increase in temperatures. The perception of climate change is shaped mainly by the associated impact of changed climatic conditions on the diseases of vegetable crops.

New pathological threats have been seen in the last few years on vegetable crops under changing climatic conditions. It has been observed that the vegetable crops have now become more prone to viral, bacterial and fungal diseases. In some of the vegetable crops like tomato, spotted wilt virus, bacterial wilt and fungal wilts have been seen to be of common occurrence. The situation, however, is entirely different under greenhouse conditions. Under protected conditions, the severity and incidence of powdery mildew and root rots were found more alarming. Among viral diseases of tomato, tospo virus and leaf curl virus have occupied a significant position. Sclerotium, Rhizoctonia and Pythium root rots of tomato and capsicum are of significant importance in greenhouses or protected structures like polyhouses. In bacterial diseases, Ralstonia solanacearum has become more devastating than ever before. Vegetable Crops suffer badly from this bacterial disease in summer, rainy and winter season.

Infested soil and surface water, irrigation water are the main sources of spread of inocula of the pathogens and can infect undisturbed roots of vegetable crops through microscopic wounds caused by the emergence of lateral roots. After infection, the wilt causing bacteria colonizes the cortex and makes its way towards the xylem vessel from where it rapidly spreads throughout the plant. It has been reported that infected roots present in soil release vast number of bacterial cells into

the rhizosphere and secondary spread thereby occurs. The race 1 of this bacterium can survive for more than 6 months on the seeds surface and in the soil. The bacteria are also reported to spread through seed.

It is important that the diseases of vegetable crops are managed on immunization-prophylaxis system comprising of management of soil through microbes, plant extracts and cakes. The microbes may include mycorrhiza, Trichoderma, Pseudomonas and Azotobacter etc. It has been reported that Azotobacter has ability to produce anti fungal antibiotics and also to fix nitrogen which improves the fertility of soil and also act as bioagent. In plant extracts, asfoetida, turmeric, onion, garlic and among cakes, karanj, mustard and neem cake are effective for the control of soilborne diseases of vegetable crops.

Out of about 51 fungicides which have been registered in India, mancozeb, sulphur, copper oxychloride, carbendazim and thiram constitute 87 per cent use in vegetable crops. The consumption of mancozeb is maximum followed by sulphur compounds, copper oxychloride, carbendazim and thiram. Mancozeb use accounts for 25 per cent followed by carbendazim (7.4%) and thiram (3.8%). A few new generation fungicides are also being used for the control of fungal diseases of vegetable crops. Important among these are strobilurin, Monceren, Fluazinaur and Famoxadone. Out of total fungicide market of about Rs. 430 crores in India, maximum fungicides use is on pome fruits (12.7%) followed by potatoes. The proportion in chillies is 7.6% and in vegetables 4.6 %. Despite some adverse effects, use of fungicides is likely to continue against vegetable diseases.

Generally, pathogens have been identified on visual basis on microscopic examination tests. Monoclonal antibodies and enzyme linked immunosorbant assay predominantly are used for detection of viruses. Nucleic acid based detection is precise and more accurate to detect pathogens. In India, most of the work is concentrated on development on PCR based diagnostic tools. Moreover, there is a need to develop the use of single nucleotide polymorphisms by making use of unique sequence polymorphisms. Molecular techniques can be used for indirect selection of disease resistance genes for their use in plant breeding programmes. Exploitation of host plant resistance against pathogens of vegetable crops has been widely used for the control of diseases. The conventional breeding for disease resistance in vegetable crops has mostly utilized major resistance genes based on the classical gene for gene system.

The legislations pertaining to plant protection were developed in India in th

early part of the 20 century. Of late with WTO coming in place, the country has challenges to appropriately compliance with the governing rules of WTO. There is urgent need for developing national standard for survey, surveillance and pest free

122

areas as well as process for carrying out pest risk analysis and to develop necessary research report for generating required scientific data.

Simulation of disease epidemic and management strategies developed in response to natural climate extremes may be useful in adopting long term climate changes. There is need to develop more effective disease surveillance and experts system for farmers advisory system in the management of vegetable diseases. Research was conducted world over on the effect of incorporated crucifer tissues on activity of the soil borne plant pathogens. There exists a great potential in the use of cruciferous plant residue for suppression of soil borne plant pathogens as an alternative to expensive and environmentally hazardous chemical means of control.

There is thus a need to concentrate on diseases of economic importance after undertaking accurate disease diagnosis for multiple diseases control based on the principles of evasion, exclusion, eradication, protection and crop improvement through conventional and molecular breeding programmes.

123

Biotic Factors and their Management under Changing Climate

RC Sharma and Meenu Gupta*

Dean, College of Horticulture,*Department of Vegetable Science

Dr YS Parmar University of Horticulture and Forestry, Nauni, Solan 173 230

Plant diseases can be infectious (caused by biotic factors) or noninfectious (caused by abiotic agents). Infectious plant diseases are caused by pathogens, living microorganisms that infect a plant and deprive it of nutrients. Bacteria, fungi, nematodes, mycoplasmas, viruses and viroids, algae, protozoa are the living agents that cause plant diseases. Fungi are the largest of these agents, while viruses and viroids are the smallest. None of these pathogens are visible to the naked eye, but the diseases they cause can be detected by the symptoms of wilting, yellowing, stunting, and abnormal growth patterns.

Biotic factors

1. Fungi

Fungi are small, generally microscopic, usually filamentous, branched, spore bearing organisms that lack chlorophyll. They have cell walls containing chitin and glucans (but no cellulose) as the skeletal components.

A group of fungal like organisms, the Oomycota generally referred to as (oomycetes), until about 1990 were earlier considered to be fungi. Majority have cell wall composed of glucans and small amount of cellulose, but not chitin. Now the members of the kingdom Chromista (also known as Straminopila) rather than Fungi; but continued to be treated as fungi because of their many other similarities to them, especially the way they cause disease in plants.

Most of the more than 1, 00,000 known fungus species are strictly saprophytic and they live on dead organic matter. About 50 species cause diseases in humans. About 50 species cause diseases in animals. More than 10,000 species of fungi can cause diseases in plants. All plants are affected by some kinds of fungi and each of the parasitic fungi can attack one or many kinds of plants.

2. Bacteria

Bacteria are second most important organisms which cause plant disease. They are prokaryotic single celled mostly achlorophyllous organisms whose body is

surrounded by cell wall and contain membranous genetic material (or chromosome). They lack membrane bound organelles such as mitochondria or plastids and also a visible endoplasmic reticulum.

Most of the bacterial species are saprophytes living on dead organic matter. There are about 200 bacterial species which are plant pathogenic. Morphologically the bacteria are rod shaped (bacilli), spherical (cocci), spiral (spirrilli), coma shaped (vibrios) or thread like (filamentous). Mostly plant pathogenic bacteria are rod shaped except streptomyces which have a filamentous branched hypha-like structure, sometimes mistakenly called as ray fungi; and mycoplasma have no definite shape due to lack of cell wall. In young cultures the rod shaped bacteria range from 0.6 to 3.5 µm in length and from 0.5 to 1µm in diameter (0.6-3.5 x 0.5-1 µm size). Single bacterium mostly appears as hyaline or yellowish white under the compound microscope. When grown on a medium, soon a colony is formed. The colonies of most of bacteria have a whitish or greyish appearance but some of them develop yellow red or other colours.

3. Viruses

Viruses are submicroscopic, intercellular, infectious entities and are composed of nucleic acid and proteins. Some viruses attack humans, animals or both and cause diseases like mumps, measles, chicken-pox, HIV, H1N1, polio, rabies etc;

thothers attack plants. In plants, tulip breaking was reported in 17 century. Viral study was started by Adolf Mayer in 1886. He proved that the sap from tobacco leaves infected with mosaic could transmit the disease to healthy leaves.

Characteristics of viruses which separate them from other causes of plant diseases are:

• They lack lipid membrane system and energy production.

• They are acellular.

• They are submicroscopic and intracellular.

• They use host machinery for their replication.

Viruses are of different shapes and sizes. They may be elongated (rigid rods or flexuous threads), spherical (isometric or polyhedral), cylindrical (bacillus-like rods). Some elongated viruses are rigid rods about 15 x 300 nm but most appear as long, thin, flexible threads that are usually 1-10 nm wide and 480-2000 nm in length. Rhabdoviruses are short bacilus-like, cylindrical rods approximately three to five times as long as they are wide ( 52-75 by 300-380 nm).

Most spherical viruses are actually polyhedral, ranging in diameter from about 17 nm (tobacco necrosis satellite virus) to 60 nm (wound tumor virus). Tomato

125

spotted wilt virus is surrounded by a membrane and has a flexible, spherical shape about 100 nm in diameter. Many plant viruses have spilt genome consisting of two or more distinct nucleic acid strands encapsidated in different-sized particles made of the same protein subunits

• Bipartite- e.g. tobacco rattle virus consisting of two rods, a long one (195 x 25 nm) and a shorter one (43 x 25 nm).

• Multi-partitite- alfalfa mosaic virus, consist of four components of different sizes.

4. Algae

Parasitic green algae are green in colour. Cephaleuros is the best known genus. It is a plant parasite living under leaf cuticle. It was first reported from in India in 19th century, causing damage to tea and coffee plantations. Now, over 400 hosts of Cephaleuros are recorded all over the world infecting hibiscus, orchids, euphorbias, citrus and forest trees. Ninety percent of the hosts are dicots.

5. Protozoa

Certain protozoa, such as trypanosomatid flagellates belonging to class Mastigophora, order Kinetoplastida, family Trypanosomatidae are accepted as plant parasites even though Koch's postulates could not be established for them. The evidence supporting the pathogenicity is more evident than that available for the fastidious bacteria and mollicutes, and so they are accepted as plant pathogens. Only the flagellates among the protozoa have been found to be associated with plant diseases.

6. Parasitic Flowering Plants

The pathogenic flowering plants, also called angiosperms can be classified as root parasites or stem parasites. Root parasites (witchweed and broomrape) are more common and more diverse taxonomically. Stem parasites include the dodders (Cuscuta) and mistletoes (Arceuthobium). The angiospermic parasites can also be classified as holoparasites (total parasites) or hemiparasites (semi-parasites). The holoparasites lack chlorophyll and are totally dependent on the host for nutrition. Thus, they are obligate parasites. The hemiparasites contain chlorophyll and make their own food and absorb water and minerals from their host. But, in some cases e.g. Arceuthobium, the photosynthesis is negligible and the parasite draws nutrition from the host. Practically, it is an obligate parasite.

Climate

It is the average weather in a place over more than thirty years. Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind,

126

precipitation, atmospheric particle count and other meteorological elemental measurements in a given region over long periods. Climate can be contrasted to weather, which is the present condition of these elements and their variations over shorter periods.

Climate change

Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions, or in the distribution of weather around the average conditions.

Causes of climate change

1. Natural causes

i. Continental drift

ii. Volcanoes

iii. The earth's tilt

iv. Ocean currents

2. Human causes

i. Greenhouse gases

ii. Carbon dioxide

iii. Methane

iv. Nitrous oxide

v. Ozone

vi. Water vapour

Effects of climate change on diseases

• The range of many diseases will expand or change.

• New combinations of pests and diseases may emerge as natural ecosystems respond to altered temperature and precipitation profiles.

• Disruption in the BCA- pathogen relationships that normally keep pathogen populations in check.

• It may add to the effect of other factors such as the overuse of pesticides and the loss of biodiversity that also contribute to plant pest and disease outbreaks.

127

Direct effects on plant diseases

• Influence spatial and temporal dispersal of propagules.

• Synchrony of pathogen propagules with sensitive crop growth stages,

• Frequency of suitable infection conditions (most fungal plant pathogens require wetness or high humidity for infection),

• Host resistance (some resistance genes are temperature sensitive),

• Speed of disease development (pathogen growth and for polycyclic pathogens—number of disease cycles)

• Pathogen survival (frost periods, length of intercrop period, etc.), which affects whether the disease is epidemic following importation of propagules from elsewhere, endemic or absent.

Plant disease occurs when three factors combine: a susceptible host, sufficient effective pathogen inoculum and suitable environmental conditions. If the three components of the disease triangle could be quantified, the area of triangle would represent the amount of disease in a plant or a plant population. Understanding the factors that trigger the development of plant disease epidemics is essential if we are to create and implement effective strategies for disease management. The interaction of three components of disease triangle with time forms the disease tetrahedron. The time is important factor in disease tetrahedron. Duration and frequency of favourable temperature and rains, the time of appearance of vector, the duration of infection cycle of particular disease and so on affects the disease development.

Effect of climate change on fungal diseases

• Survival structures of soil borne fungi are not affected significantly.

• Increased survival of host or debris borne fungi.

• Increased survival of host or debris borne fungi.

• Early migration of air borne fungi-early infection.

• Monocyclic diseases those caused by Uromyces and Sclerotinia spp. are not affected.

• Climate change affects polycyclic diseases caused by Peronospora, Colletotrichum and Phytophthora.

128

• Elevated CO increases canopy size and density of plants resulting in a 2

greater biomass production and microclimates may become more conducive for rusts, powdery mildews, blights and leaf spot diseases.

• Late blight severity and control costs may be increased by climate change.

• Higher temperatures will speed up the life cycle of many pathogenic fungi, multiplying inoculum in a shorter time and consequently increasing the infection pressure.

• Prolonged generations of diseases will be able to infect crops at a later growth stage then at present.

• Affect the expression of the plant resistance traits in a positive or negative way.

• When over a large cropping area the genetic variation of the crop is low and a new or adapted strain is becoming dominant in the pathogen population, the effects can be dramatic.

Effect of climate change on bacterial diseases

• Abundant moisture increases multiplication, oozing and spread of bacteria.

• Expected increase in frequency and intensity of summer storms with high winds, rain and hail will increase wounding of plants and increased bacterial infestation.

• Host or debris borne and vector borne survival is expected to increase.

• Milder, shorter winters will have little effect on soil borne bacterial pathogens.

• Warmer drier summers expected limit bacterial diseases.

Effect of climate change on viral diseases

• Increased survival of vectors in milder winter temperatures.

• Increased survival of alternate weed hosts of viruses.

• Increased wounding of plants and therefore increased transmission by mechanical means.

• Viruses that are present in green houses such as pepipo mosaic virus may establish infection in the field

129

Effect of climate change on Phytoplasma

• Milder winter increases survival of infected perennial weed host.

• Survival of insect vector is increased in milder winter temperatures and higher summer temperatures will increase their reproductive rates.

Effect of climate change on parasitic plants

• Changes in photosynthesis and stomatal functioning.

• Enhanced photosynthesis of the hemiparasite and host will increase parasite carbon gains but may also increase the demand for host mineral nutrients.

• Disrupt the match between host and parasite range and migration.

References:

Agrios, GN. 2005. Plant Pathology. Fifth edition. Academic Press, Massachusetts, 922p.

Coakley, Stella Melugin, Scherm, Harald and Chakraborty, Sukumar. 1999. Climate change and plant disease management. Annu. Rev. Phytopathol. 37:399–426.

Ghini, Raquel, Hamada, Emília and Bettiol, Wagner. 2008. Climate change and plant diseases. Sci. Agric. 65: 98-107.

Singh, RS. 1984. Introduction to the principles of Plant Pathology. Oxford and IBH Publishing Co. Pvt. Ltd., Calcutta, 534p.

130

Integrated Disease Management in Cole Crops

NP Dohroo

Directorate of ResearchDr YSP University of Horticulture & Forestry Nauni, Solan 173230 HP

Cole crops are affected by different fungal, bacterial and viral diseases. The important diseases are Pythium/ Rhizoctonia damping off, wire stem, downy mildew, Alternaria leaf spots, Sclerotinia rot, black rot, white rust or blisters, Phoma black leg, cabbage yellows, Ring spot and cauliflower mosaic. Among these diseases, damping off, Sclerotinia rot and black rot are important ones. All these diseases should be managed by following integrated disease management practices. Emphasis should be given to eradicate cruciferous weeds from around the field, use of well drained disease free plots, use of disease free seedlings and very long crop rotation.

Damping off

Plants show damping off symptoms. The causal organisms for the disease are Pythium, Fusarium, Rhizoctonia, Sclerotium and Sclerotinia. For the control of the disease, seeds should be treated with thiram or captan. Formaldehyde solution drench may be made for the control of pre-emergence damping off and mancozeb and carbendazim drench for post emergence damping off. Besides, change of nursery site, soil solarization, soil fallowing and soil biodisinfestation are also recommended for the control of the disease.

Wire stem

It is a seedling disease. Rhizoctonia solani is the causal oraganism. The disease can be controlled by transplant dipping in carbendazim solution and is recommended.

Downy mildew

Purplish brown spots appear on the leaves and stalks are abruptly bent. Floral buds are atrophied. The causal organism is Hyaloperonospora parasitica. Conidia germination (10 ºC), infection (15 ºC), Lesion development (20 ºC) and colonization (25 ºC) take place during the disease development. Cabbage (January King and Wall, Spitzkool), Cauliflower (Igloo, Snowball Y and Snowball 7) show resistance to the disease. HWT, Ridomil MZ or mancozeb are important management practices.

White rust or blisters

Local and systemic infection results in development of isolated white pustules. Hypertrophy, cruciform nuclear division, akaryotic phase, Acidic soils are important features of the disease. Albugo candia/A. cruciferum is the causal organism. Disease development take place at 15-25 ºC (20 ºC). COC and Ridomil are recommended as sprays for the control of the disease.

Club roots

Woronin (1877) reported the disease for the first time. Flagging of leaves and formation of spindles in roots are important symptoms. The pathogen is an obligate endoparasites named Plasmodiophora brassicae. The disease is managed by decreasing acidity by adding hydrated lime or slaked lime Ca (OH) @ 20 t/ha. Soil 2

solarisation/ Benomyl drenching also checks the disease. Some Cabbage varieties (Badget Shipper, Kilaxy), Cauliflower (Clapton) show resistance to the disease.

Sclerotinia rot

The disease was reported for the first time from Saproon valley of Solan district in H.P. during 1973. It reduces seed yield by 70-80 %. Sclerotia have myceliogenic, sporogenic and carpogenic germination. Favourable conditions of the disease are 20-25 ºC temperature and 90 % RH. Flooding (6 wks) before planting manages the disease. Janavon, EC 178303, EC178307) are resistance sources. Other management practices are paddy rotation and removal of lower yellow leaves.

Black Rot

Wedge shaped symptoms appear on the leaves. Xanthomonas campestris pv. campestris is the causal bacterium which survives through seed. HWT+ Bactrinashak (2-bromo-2-nitropropane-1, 3-diol) @3 g/10 l water may be used for seed treatment.

Alternaria leaf spots

The pathogen is seed borne. A. brassicae form very small light spots while A. brassicicola forms small and dark spots. HWT (50 ºC/30 min) is recommended to exclude the bacterium from the seed. Mancozeb sprays control the disease.

Ring spot

Spots are bordered by green bands. The causal organism is Mycosphaerella brassicicola. 15-22 ºC temperature favours the disease. HWT is recommended for the control of the disease.

132

Black Leg

The disease forms characteristic canker symptoms at 18.3 ºC. Phoma lingam (=Leptosphaeria maculans) is the causal organism. Asci are bitunicate. Conidia are released in cirrhus. Toxin named sirodesmin is formed by the pathogen. The pathogen is seed borne, Accordingly, Thiram and Captan are recommended for seed treatment.

Cabbage Yellows

A lateral curling of stem and leaves occur due to the disease. Fusarium oxysporum f. sp. conglutinans is the causal organism.

Cauliflower Mosaic

Vein clearing and banding besides mosaic are the common symptoms. Caulimovirus (CaMV) is the causal virus. Virions are isometric (50 nm). Aphids (Brevicoryne brassicae and Myzus persicae) transmit the disease. Control of aphid vectors, use of virus free seed and application of neem derivatives are important management practices.

The diseases of cole crops should be managed by following IDM practices right from seed and seedbeds. Only sterilized soil or soil that has not previously had brassicas for several years should be used. Seeds should be hot water treated and also treated with a suitable fungicide. Plant density should permit adequate light and air penetration. Factors such as deep planting, reduced seed vigour and excessively cold, hot, moist or saline soils that delay seed emergence should be avoided. Deficiencies of calcium, potassium and nitrogen or excessive nitrogen may promote disease. A field rotation with non-brassica crops should be practiced for at least three years. Avoid mounding of soil onto lower leaves when cultivating. Isolate (if possible) or avoid the use of infested fields for brassica crops for about atleast few years. Do not apply clubroot infested manure on land to be used to grow brassicas. Cattle fed infected plant material can pass the fungus spores in manure, therefore it is best not to put contaminated manure back on the field. Rotate crops and fields as a preventative measure before soil borne diseases appear. Allow at least three years rotation between growing susceptible crops. Clean and disinfect all equipment used on infested land before using on a non-contaminated field. Control susceptible weeds whenever possible. Weeds of the mustard family will maintain or increase the level of infestation of soil borne diseases in a field. Use disease free transplants. The only way to ensure clean transplants is to use sterile soil. In the early stages of infection, plants may not show any signs of disease, so it is essential to purchase plants from a reliable source or to follow the procedures for producing healthy plants. Use clean, certified seed or a hot water seed treatment if certified seed is not

133

available. Practice long rotations between Cole crops, avoid over head irrigation and make sure to incorporate plant debris.

References:

Bhagat, S., and Pan, S. (2008). Biological management of root and collar rot of cauliflower (Rhizoctonia solani) bya talc-based formulation of Trichoderma harzianum Rifai. Journal of biological control, 22 (2), 483-486.

Dabbas, M. R. Singh, D.P., and Yadav, J. R. (2009). Management of Rhizoctonia root rot of cauliflower through IDM practices. International journal of plant protection, 2 (1), 128-130.

Dennis, C., and Webster, J. (1971a). Antagonistic properties of species groups of Trichoderma. I. Production of non-volatile antibiotics. Transactions of the British Mycological Society, 57, 25-39.

Dennis, C., and Webster, J. (1971b). Antagonistic properties of species groups of Trichoderma. II. Production of volatile antibiotics. Transactions of the British Mycological Society, 57, 41-48.

Dennis, C., and Webster, J. (1971c). Antagonistic properties of species groups of Trichoderma. III. Hyphal Interaction. Transactions of the British Mycological Society, 57, 363-369.

Fajola, A.O., and Alasoadura, S.O. (1975). Antagonistic effects of Trichoderma harzianum on Pythium aphanidermatum causing the damping-off disease of tobacco in Nigeria. Mycopathologia, 57:47-52.

Fourie, P.H., Halleen, F. J., van der Vyver, and W. Schreuder. (2001). Effect of Trichoderma treatments on the occurrence of decline pathogens in the roots and rootstocks of nursery grapevines. Phytopathologia Mediterranea, 40, 473–478.

Harman, G. E., Petzoldt, R., Comis, A., and Chen, J. (2002). Interactions between Trichoderma harzianum strain T22 and maize inbred line Mo17 and effects of these interactions on diseases caused by Pythium ultimum and Colletotrichum graminicola. Phytopathology, 94 (2), 147–153.

Kohl, J., Tongeren, C.A.M., van Groenenboom de Haas, B. H., Hoof, R. A., van Driessen, R., and Heijden, L. van der. (2010). Epidemiology of dark leaf spot caused by Alternaria brassicicola and Brassicae in organic seed production of cauliflower. Plant Pathology, 59, (2), 358-367.

Mukherjee, P. K., and Mukhopadhyay, A.N. (1995). Evaluation of Trichoderma harzianum for biocontrol of Pythium damping-off of cauliflower. Indian phytopathology, 48: 101-102.

134

Mukherjee, P.K., Upadhyay, J.P., and Mukhopadhyay, A.N. (1989). Biological control of Pythium damping-off of cauliflower by Trichoderma harzianum. Journal of biological control, 3, 119-124.

Sharma, P., Sain, S. K., and James S. (2003). Compatibility Study of Trichoderma Isolates with Fungicides against Damping-off of Cauliflower and Tomato Caused by Pythium aphanidermatum. Pesticide Research Journal, 15: 133-138.

Sivan, A, Elad, Y., and Chet I. (1984). Biological control effects of new isolate of Trichoderma harzianum on Pythium aphanidermatum. Phytopathology, 74, 498-501.

Tran, N. H. (2010). Using Trichoderma species for biological control of plant pathogens in Vietnam. Journal of International Society for Southeast Asian Agricultural Sciences, 16, (1), 17-21.

135

Diagnosis and Management of Vegetable Diseases

Sandeep Kansal

Department of Vegetable ScienceDr YS Parmar University of Horticulture and Forestry, Nauni, Solan, HP 173 230

Diagnosis is the process of determining the cause of a problem. It can be a long or short process depending on one's ability and the nature of the problem. Once the cause is known, an appropriate control strategy can be developed.

Disease Diagnosis

Plant pathologists take many different approaches to diagnosing plant disease problems. The first step is to decide whether the problem is a plant disease. The broadest definition of plant disease includes anything that adversely affects plant health. This definition can include such factors as nutrient deficiencies, mechanical damage, air pollution, and pathogens. A stricter definition usually includes a persistent irritation resulting in plant damage. This excludes mechanical damage such as tool injury to plants or natural events such as hail or lightning. A very strict definition includes only those (living) things that replicate themselves and spread to adjacent plants. This includes such biological organisms as nematodes, fungi, bacteria, and viruses. Plants damaged by macroscopic organisms, such as deer, rodents, and birds usually are not considered to be diseased.

Many novices use the picture-book method of diagnosis: looking at textbook pictures of problems and attempting to match the problem with the picture. Although this method is useful for simple and common problems, it is usually inefficient and inaccurate for more complex or difficult problems.

Symptoms and signs are used to diagnose the condition of a plant. Symptoms are the physical characteristics of disease expressed by the plant. Symptoms can include wilt, galls, cankers, rots, necrosis, chlorosis, and general decline. Signs are physical evidence of the pathogen causing the disease. Signs can include fungal fruiting bodies (such as mushrooms or pycnidia), mycelia, bacterial slime, presence of nematodes or insects, or the presence of insect holes accompanied by sawdust or frass. Again, these terms are defined in the glossary.

There is no one key set of questions or techniques for diagnosing plant diseases. Experience and practice are the best teachers. It is easier to diagnose plant problems by making a personal, on-site inspection. Subtle influences of the site, plant environment, and possible management practices can be seen that may have been overlooked by the grower. Difficulties arise when the diagnostician is presented only

a portion of the plant because that portion may or may not indicate the real problem. The worst situation is a request for a diagnosis by phone, because misunderstandings and an inaccurate diagnosis can easily occur. However, sometimes this is the only contact someone may have with a diagnostician.

The Systematic Approach

The approach involves defining the real problem and distinguishing between living and nonliving causes of plant damage by looking for patterns, determining the development of the damage, and building a case history of the problem. With these steps, it is usually easy to narrow the possibilities and to turn to appropriate reference materials including textbooks, herbarium samples, and knowledgeable specialists.

Define the Real Problem Identify the plant and what it should look like at this time of year. A grower or gardener may mistake a normal stage of development for a diseased plant. Describe the abnormality in terms of symptoms and signs. Although a plant may exhibit symptoms of wilting, the real problem may be due to rotted roots, a girdled stem, or lack of water. Determine what part(s) of the plant is/are affected. The rest of the procedure involves distinguishing between living and nonliving factors.

Look for Uniform or Non uniform Patterns Uniform damage is indicative of nonliving factors. Damage may occur on many plant species in the same area, on all the plants in a particular row or block, on all the leaves or shoots on one side of the plant, or on the same-age portion of each leaf. Non uniform damage to plants is indicative of living factors such as pathogens or insects. This damage shows up as scattered affected plants among a community of plants, scattered leaves or shoots on a single plant, or scattered spots on a single leaf.

Determine the Time Development of the Damage If damage does not spread or there is a clear line of demarcation between damaged and non damaged tissues, this is indicative of nonliving factors. Spread of the damage from plant to plant or to other plant parts over time indicates damage by a living organism.

Look for Specific Symptoms and Signs Look for signs such as fungal fruiting bodies, mycelial threads, bacterial slime, presence of insects, mites, or holes with frass. Look for symptoms of nonliving factors that may be caused by extremes of temperature, light, water, mechanical factors or chemical factors as indicated by uniform patterns. Check references for probable diseases of the identified plant. The samples may have to send to an appropriate laboratory to continue to identify possibilities.

Once it is determined that a real problem exists and is caused by a living organism, it need to decide what type of organism may be causing the damage. There are many

137

fungal and viral diseases of plants and a few caused by bacteria and nematodes. Some insect problems can mimic diseases.

Begin by establishing which plant part or growth stage is showing symptoms. Are symptoms showing on roots, tubers, bulbs, corms, seedling, foliage, stem, branches, flowers, fruit, or on the entire plant? Often, one must next decide whether the symptoms are on the outside of the plant or whether you need to cut into it to see the symptoms.

Root Symptoms

External root symptoms include galls, discoloration, or death of roots or parts of roots. Some fungal diseases, such as club root of cabbage, also cause galls. Root-knot nematodes, Meloidogyne spp., can cause large or small irregular galls. Small discolored, dead areas may be caused by a large variety of fungi and root-lesion nematodes, Pratylenchus spp. General death of the entire root system or just feeder roots is indicative of many fungi. Injury to the root system often includes yellowing, stunting, or wilting of aboveground parts. Many fungi, such as Verticillium and Fusarium, will cause an internal vascular discoloration as will some bacterial wilts.

Symptoms on Storage Organs (Tubers, Bulbs, Corms, etc.)

Discolored or dead areas that penetrate deep into the storage organs are caused by many fungi and some bacteria. Dry rots are often caused by fungi which may produce mycelia or spores. Soft rots are usually associated with bacteria such as Erwinia and can be accompanied by strong, repulsive smells. Many times bacterial soft rots will closely follow rots caused by fungi, making diagnosis difficult. Scurfy dead tissue on the surface may be caused by a variety of myxomycetes, such as powdery scab of potato. The filamentous bacterium Actinomyces scabies causes common scab of potato. Galling of storage organs can be caused by both fungi and nematodes. Internal problems, such as ring rot of potato, can be caused by bacteria fungi or by several viruses.

Seedling Diseases

If seedlings fail to emerge, or fall over and die, this is usually referred to as damping-off. Fungi such as Rhizoctonia, Pythium, and Fusarium are common and affect seedlings just at or below the soil line.

Leaf Symptoms

Discoloration (yellowing or shades of green), which is localized or in distinct patterns, usually indicates a virus. Other leaf symptoms may occur with viral infections. A general or uniform yellowing may indicate a root rot of some kind, so

138

there is need to examine the entire plant. Dead areas on leaves can be caused by fungi or bacteria. Necrotic areas caused by fungi may contain hyphae or fruiting bodies, particularly after incubation in a warm, moist environment. Necrotic areas caused by bacteria may be distinguished by water-soaked margins or bacterial streaming. Small rusty red, brown, or black spots or stripes may be caused by rust and smut fungi. Distinctive spores can usually be found in these spots. Leaf distortion (elongated, dwarfed, etc.) can be caused by several viruses. Leaf galls usually are caused by fungi, such as peach leaf curl and azalea leaf gall. Viruses and nematodes rarely cause galls on the leaf. Moldy white appearance of leaves indicates powdery or downy mildew. Wilting indicates lack of water which may be due to one of the vascular wilt fungi, root rots, or bacterial wilts. Other parts may need to be examined for an accurate diagnosis.

Stem and Branch Disorders

Complete or partial death of woody stems or branches, usually referred to as cankers, can be caused by a large variety of fungi and a few bacteria. Cutting into the wood with a knife may reveal a sharp border between healthy and infected tissue. Look for spore-bearing structures of fungi or induce sporulation in a moist chamber. Some bacterial cankers will excrete a sticky ooze in the spring.

Flower Symptoms

Abnormal color changes and/or distortions can be caused by several different viruses. Partial or complete death of flower parts can be caused by fungi and bacteria. Fungi usually produce characteristic spores; bacterial infections can appear water soaked.

Fruit Symptoms

Fungi cause a wide variety of decays, rots, and superficial spotting or russetting. Important symptoms include specific color of rotted tissue, firmness of the tissue, and signs such as spores or spore-bearing structures. Viruses can cause discolorations and malformations. Bacteria may cause discrete spots on fruit in certain field situations or soft rots in storage.

Principles of Plant Disease Management

After a plant disease is diagnosed, the job is only half finished. The equally challenging task of designing the proper control recommendation is next. Understanding the specific disease or the life cycle of the pathogen involved is necessary to make an adequate control recommendation.

139

The Disease Triangle

Three major factors contribute to the development of a plant disease: a susceptible host, a virulent pathogen, and a favorable environment. A plant disease results when these three factors occur simultaneously. If one or more of these factors do not occur, then the disease does not occur. The genetic makeup of the host plant determines its susceptibility to disease. This susceptibility or resistance may be determined by various physical and biochemical factors. Plant stature, growth habit, cuticle thickness, and stomatal shape are a few physical factors that influence disease development. The plant's developmental stage also may influence disease development. Pathogens differ in their ability to survive, spread, and reproduce. Environmental extremes of temperature, light, or moisture can accentuate many diseases. Cool, moist conditions are ideal for many fungal pathogens.

The Disease Cycle

Understanding the disease cycle is important when considering control options. Learning the chain of events that contribute to a disease helps point out the weakest links. Control measures can then be used to break the cycle. Most pathogens must survive an adverse period, usually winter, when they do not actively incite plant diseases. This overwintering inoculum re-infects or continues infecting the plant host in the spring. Some diseases are characterized by a single cycle during the year. Other diseases continually produce new inoculum, repeating the cycle many times during the course of a single growing season.

Disease Control

The five basic principles of plant disease control are: exclusion, avoidance, eradication, protection, and resistance. These principles work at federal, state, county, and personal levels.

Exclusion This includes quarantines, inspections, and certification. Plant material is examined to prevent entry of a disease that does not already occur in a particular country, state, or geographic area.

Avoidance If the disease does occur in an area, there are techniques to avoid disease development. Choice of planting site, time of planting, storage conditions, or avoiding wounds is a few of these techniques. Phytophthora root rots can be avoided by not planting in heavy, poorly drained soils. Planting later in the year when soils are dryer and warmer will avoid some damping-off diseases common to many vegetables. Wounding can cause entry points for pathogens or weaken a plant to the point that it cannot defend itself. Avoiding wounds also helps to control the bacterial diseases which need an injury to begin the infection process. Planting certified virus-free stock is a good way to avoid virus-related diseases.

140

Good horticultural practices such as proper fertility, pruning, watering, and proper training will go a long way to help control plant diseases.

Eradication When a plant is infected or an area is infested with a plant pathogen, eradication can eliminate or reduce the disease threat. Rotation, sanitation, heat treatment, eliminating the alternate host, and certain chemicals can be used to reduce or eliminate diseases. Crop rotation is a common method in commercial vegetable production. It is necessary to know the pathogen and its host range. Rotation reduces soil populations of fungi or nematodes only if non-host plants are used.

Removing plant debris (sanitation) is important where pathogens may overwinter. Raking leaves, removing rotted fruit and picking up old vines all are part of sanitation. Once collected, dispose of debris by burning, burying, or hot composting. Field burning is another method of sanitation which destroys grass stubble where plant pathogens may overwinter.

Rusts are a group of fungi that can complete their life cycle on two or more different hosts. Eliminating an alternate host may help reduce pressure from these diseases. Heat treatment is usually used to eliminate viruses from propagation material.

Certain chemicals can be used to eliminate infections or infestations. Soil can be fumigated to reduce populations of certain fungi and nematodes. Some fungicides have kickback activity, meaning that infections of some fungi can be stopped if the chemical is applied within a few days after the infection has started.

Protection: Protection is treating a healthy plant before it becomes diseased. There are both biological and chemical means of protection.

Chemical protection is one of the most widely used means of control. Some fungicides (such as copper and sulfur products) are allowed for use under several "organic" growing guidelines. It is necessary to know the disease cycle and host susceptibility to get good control using fungicides. Proper timing, coverage, and selection of fungicides is also needed.

Resistance: Resistance is a term sometimes mistakenly used interchangeably or in conjunction with "immunity," "tolerance," and "susceptibility." These terms describe the inherent genetic makeup of the plant and thus its reaction to plant pathogens. Resistance and its opposite, susceptibility, are levels or degrees of a plant's reaction. Some cultivars of a plant can be more or less resistant (or susceptible) than another cultivar. Resistant cultivars can still become diseased but not as much as (or more than) another. If a plant does not ever become diseased, then the term "immune" can be used. Tolerance describes a plant (usually a food crop) that may become diseased but produces yields similar to a healthy plant.

141

Lists of resistant plants can be found in many texts and seed catalogues. Planning ahead is essential and planting resistant cultivars is the easiest means of disease control.

Knowing what diseases a plant is susceptible or resistant to can help in the diagnostic process. One can eliminate possibilities by knowing which diseases are likely to occur.

Summary

Experience and practice are the best teachers of plant disease diagnosis. Examination of the plants physical environment and management history are essential. Observing patterns and specific symptoms and signs are important in arriving at a correct diagnosis. Once diagnosed, the proper control measures can be formulated. Knowledge of the host, pathogen life cycle and environmental factors also aid selection of the most effective control measures. A combination of exclusion, avoidance, resistance, eradication, and protection will control most plant diseases. References:

thAgrios, G. N. 1997. Introductory Plant Pathology. 4 ed. Academic Press, New York, NY.

Alfieri, S. A., Jr., K. R. Langdon, J. W. Kimbrough, N. E. El-Gholl, and C. Wehlburg. 1994. Diseases and Disorders of Plants in Florida. Fla. Dep. Agric. Consumer. Serv. Div. Plant Ind. Bull. No. 14.

Hansen, M. A. and R. L. Wick. 1993. Plant disease diagnosis: present and future prospects. Advances in Plant Pathology 10:65-126.

Holmes, G. J., E. A. Brown, and G. Ruhl. 2000. What's a picture worth? The use of modern telecommunications in diagnosing plant diseases. Plant Dis. 84:1256-1265.

Putnam, M. L. 1995. Evaluation of selected methods of plant disease diagnosis. Crop Protection 14:517-525.

ndSherf, A.F., and A.A. MacNab. 1986. Vegetable Diseases and Their Control, 2 ed.

John Wiley and Sons, Inc., New York.Shutleff, M. C. and C. W. Averre. 1997. The plant disease clinic and field diagnosis of

abiotic diseases. American Phytopathological Society, St. Paul, MN.

142

Integrated Disease Management in Solanaceous and Leguminous Vegetables

Sandeep Kansal

Department of Vegetable ScienceDr YS Parmar University of Horticulture and Forestry, Nauni, Solan, HP 173 230

Amongst the vegetable crops, solanaceous and leguminaceous vegetables are the most remunerative crops which have ameliorated the economic conditions of the farmers of Himachal Pradesh. The intensive cultivation of these crops year after year also ensures the survival and cumulative build up of the inocula of various pathogens posing threat to the successful cultivation. As the methods of management vary with the nature and cause of individual disease, therefore an accurate diagnosis is essential to prevent waste of time and material inputs. Besides, the information on nature of diseases occurring at various stages during the cycle of a crop is also necessary for developing integrated management schedule of multiple disease for a given geographical area. Thus the adoption of such a schedule which is crop protection oriented, efficient and cost effective is almost essential along with other inputs for the sustenance and realization crops to the extent of the genetic potential. This write up describes the list of the diseases affecting tomato and peas and their integrated management.

Diseases of Tomato & their Management

Tomatoes (Solanum lycopersicum L.) can be grown on almost any moderately well-drained soil type. A good supply of organic matter can increase yield and reduce production problems. Tomatoes and related vegetables, such as potatoes, peppers and eggplants, should not be planted on the same land more than once in three years. Ideally, any cover crop or crop preceding tomatoes should be members of the grass family. Corn, an excellent rotation crop with tomatoes, supplies large amounts of organic matter and does not promote the growth of disease organisms that attack tomatoes. Certified seeds and plants are recommended and should be used whenever possible.

BACTERIAL WILT

Bacterial wilt or Southern bacterial blight is a serious disease caused by Ralstonia solanacearum (formerly Pseudomonas solanacearum). This bacterium survives in the soil for extended periods and enters the roots through wounds made by transplanting, cultivation or insects and through natural wounds where secondary

roots emerge. Disease development is favored by high temperatures and high moisture. The bacteria multiply rapidly inside the water-conducting tissue of the plant, filling it with slime. This results in a rapid wilt of the plant, while the leaves stay green. If an infected stem is cut crosswise, it will look brown and tiny drops of yellowish ooze may be visible.

Prevention and Treatment: Control of bacterial wilt of plants grown in infested soil is difficult. Rotation with non-susceptible plants, such as corn, beans and cabbage, for at least three years provides some control. Do not use pepper, eggplant, potato, sunflower or cosmos in this rotation. Remove and destroy all infected plant material. Plant only certified disease-free plants. Chemical control is not available against this disease.

Early Blight

This disease is caused by the fungus Alternaria solani and is first observed on the plants as small, black lesions mostly on the older foliage. Spots enlarge and concentric rings in a bull's eye pattern can be seen in the center of the diseased area. Tissue surrounding the spots may turn yellow. If high temperature and humidity occur at this time, much of the foliage is killed. Lesions on the stems are similar to those on leaves, sometimes girdling the plant if they occur near the soil line (collar rot). On the fruits, lesions attain considerable size, usually involving nearly the entire fruit. Concentric rings are also present on the fruit. Infected fruit frequently drops. The fungus survives on infected debris in the soil, on seed, on volunteer tomato plants and other solanaceous hosts, such as Irish potato, eggplant, and black nightshade.

Prevention and Treatment: Use resistant or tolerant cultivars. Use pathogen-free seed and do not set diseased plants in the field. Use crop rotations, eradicate weeds and volunteer tomato plants, fertilize properly, and keep the plants growing vigorously. If disease is severe enough to warrant chemical control, select one of the following fungicides: maneb, mancozeb, chlorothalonil, or fixed copper. Follow the directions on the label.

Late Blight

Late blight is a potentially serious disease of potato and tomato, caused by the fungus Phytophthora infestans. Late blight is especially damaging during cool, wet weather. The fungus can affect all plant parts. Young leaf lesions are small and appear as dark, water-soaked spots. These leaf spots will quickly enlarge and a white mold will appear at the margins of the affected area on the lower surface of leaves. Complete defoliation (browning and shriveling of leaves and stems) can occur within 14 days from the first symptoms. Infected tomato fruits develop shiny, dark or

144

olive-colored lesions, which may cover large areas. Fungal spores are spread between plants and gardens by rain and wind. A combination of daytime

îtemperatures in the upper 70 F with high humidity is ideal for infection.

Prevention and Treatment: The following guidelines should be followed to minimize late blight problems:

·Keep foliage dry: Locate your garden where it will receive morning sun.

·Allow extra room between the plants, and avoid overhead watering, especially late in the day.

·Purchase certified disease-free seeds and plants. There are no late blight-resistant tomato cultivars.

·Destroy volunteer tomato and potato plants and nightshade family weeds, which may harbour the fungus.

·Do not compost rotten, store-bought potatoes.

·Pull out and destroy diseased plants.

·If disease is severe enough to warrant chemical control, select one of the following fungicides: chlorothalonil, fixed copper, maneb or mancozeb. Follow the directions on the label.

Bacterial Spot

This disease is caused by the bacterium Xanthomonas vesicatoria, which attacks green but not red tomatoes. Peppers are also attacked. The disease is more prevalent during wet seasons. Damage to the plants includes leaf and fruit spots, which result in reduced yields, defoliation and sun- scalded fruit. The symptoms consist of numerous small, angular to irregular, water-soaked spots on the leaves and slightly raised to scabby spots on the fruits. The leaf spots may have a yellow halo. The centres dry out and frequently tear.

The bacteria survive the winter on volunteer tomato plants and on infected plant debris. Moist weather and splattering rains are conducive to disease development. Most outbreaks of the disease can be traced back to heavy rainstorms that occurred in the area. Infection of leaves occurs through natural openings. Infection of fruits must occur through insect punctures or other mechanical injury.

Bacterial spot is difficult to control once it appears in the field. Any water movement from one leaf or plant to another, such as splashing rain drops, overhead irrigation, and touching or handling wet plants, may spread the bacteria from diseased to healthy plants.

145

Prevention and Treatment: Only use certified disease-free seed and plants. Avoid areas that were planted with peppers or tomatoes during the previous year. Avoid overhead watering by using drip or furrow irrigation. Remove all diseased plant material. Prune plants to promote air circulation. Spraying with fixed copper will control the disease. Follow the instructions on the label.

Buckeye Rot

Buckeye rot is a disease of the fruit caused by the fungus Phytophthora parasitica. The first fruit symptoms appear as brownish spots, often at the point of contact between the fruit and the soil. As the spots enlarge, dark, concentric rings can be seen. Lesions of buckeye rot resemble those of late blight, except that the former remain firm and smooth, whereas late blight lesions become rough and are slightly sunken at the margins. Under moist conditions, a white, cottony fungal growth appears on the buckeye rot lesions. With time, the entire fruit will rot. The fungus does not affect the foliage. The disease is most common during periods of prolonged warm, wet weather and in poorly drained soils. The fungus survives in the soil and is spread by surface water and rain. Peppers are also susceptible to this disease.

Prevention and Treatment: Avoid compacted, poorly drained soils (grow plants in raised beds). Rotation, sanitation, staking and mulching will help reduce the disease. Fungicides applied for late blight control will also control buckeye rot.

Fusarium Wilt

This is a warm-weather disease caused by the fungus Fusarium oxysporum. The first indication of disease in small plants is a drooping and wilting of lower leaves with a loss of green color followed by wilting and death of the plant. Often leaves on only one side of the stem turn golden yellow at first. The stem of wilted plants shows no soft decay, but when cut lengthwise, the woody part shows a dark brown discoloration of the water-conducting vessels. The fungus is soil-borne and passes upward from the roots into the water-conducting system of the stem. Blocking of the water-conducting vessels is the main reason for wilting. Invasion occurs through wounds in roots growing through infested soil. Long-distance spread is through seed and transplants.

Prevention and Treatment: Control can be obtained by growing plants in pathogen-free soil, using disease-free transplants and growing only varieties resistant to races 1 and 2 of Fusarium wilt. Raising the soil pH to 6.5-7.0 and using nitrate nitrogen rather than ammonical nitrogen will retard disease development. No chemical control is available.

146

Seedling Disease (Damping-Off)

The fungi Pythium and Rhizoctonia cause damping-off of tomato seedlings. Seedlings fail to emerge in the greenhouse or small seedlings wilt and die soon after emergence or transplanting. Surviving plants have water soaked areas on the stem close to the soil line.

Prevention and Treatment: Damping-off is often a problem in plants that are planted too early in the spring. The fungi are more active in cool, wet, rich soils. To prevent damping-off, take these precautions:

·Start seeds indoors in sterilized potting mix.

·Do not start seeds in soil that has a high nitrogen level. Add Nitrogen fertilizer after the seedlings have produced their first true leaves.

·Allow the surface of the soil to dry between waterings.

Viruses

Different viruses cause different symptoms on tomato. Symptoms of virus infection may appear as light and dark green mottling of the leaves. With tomato spotted wilt virus (TSWV), plants are stunted, bronzed or spotted, or have prominent purple veins. Fruits may have yellow spots. Tobacco mosaic virus (TMV) causes mottling of older leaves and may cause malformation of leaflets, which may become shoestring-like in shape. Viruses are highly infectious and readily transmitted by any means that introduces even a minute amount of sap from infected into healthy plants.

Prevention and Treatment: There are no chemical controls for viruses. Destroy infected plants promptly. Wash hands thoroughly after smoking (the tobacco mosaic virus may be present in certain types of tobacco) and before working in the garden. Eliminate perennial weeds near the garden. Control insects (thrips and whiteflies) that carry viruses. Rotate tomatoes with crucifers (such as cabbage, broccoli and turnips).

Peas Diseases & its management

Ascochyta Blight

Blight symptoms caused by the three different Ascochyta species are difficult to distinguish from each other in the field. However, identifying which fungus is causing the symptom is not usually necessary, as the control measures are similar. Most symptoms observed in pea fields are due to mycosphaerella blight caused by

147

Mycosphaerella pinodes. Early symptoms are most commonly observed under the plant canopy, on lower leaves, stems, and tendrils, where conditions are more humid. Symptoms first appear as small, purplish-brown, irregular flecks. Under continued humid conditions, the flecks enlarge and coalesce, resulting in the lower leaves becoming completely blighted. Severe infections may lead to girdling of the stem near the soil line, which is known as foot rot . Foot rot lesions are purplish-black in colour and may extend above and below the soil line. Foot and stem lesions girdle and weaken the stem, leading to crop lodging and yield loss.

Disease lesions develop on pods under prolonged moist conditions or if the crop has lodged. Pod lesions are initially small and dark, but may become extensive and lead to early pod senescence . Severe pod infection may result in small, shrunken or discoloured seed; or alternatively, seed may show no symptoms

Ascochyta fungi overwinter in seed, soil or infested crop residue. Infested crop residue is the primary source of infection in the main pea production regions. Ascochyta blight is favoured by wet weather, particularly frequent showers. The optimal temperature for infection and lesion development is around 20°C. If the canopy remains dense and wet into the flowering stage, lesions will continue to develop on lower leaves and stems. In the absence of rain, both spore dispersal and lesion growth will be slowed or completely arrested.

Management

1. Use disease free seed

2. Follow three to four year rotation

3. Treaty the seed with carbendazim or thiram @ 2g/kg seed or with Trichoderma @ 5 g/kg seed

4. Spray carbendazim @ 0.05% during the disease development period at 7-10 days interval

Fusarium wilt ( Fusarium oxysporum f sp. pisi)

1. Yellowing of lower leaves and stunting of plants

2. Internal woody stem tissue is often discolored turning lemon brown to orange brown

3. Seed and soil borne

4. Wet soil and temperature range 24-28° C favour disease development

Mangement

1. The cultural operation adopted for ascochyta blight should be followed

148

2. Apply Trichoderma @ 2.5 kg/ 50 kg FYM at the time of sowing

3. Drench the affected plant with benomyl (benlate) @ 0.1 %

Bacterial blight (Pseudomonas syringeae pv. pisi, P. syringeae pv. Syringeae)

1. Affects all above ground plant parts

2. Produces water soaked spots which later become darker and finally necrotic

3. Mainly seed borne

4. Disease spread through splashes (overhead irrigation, rains)

Management

1. Use of clean and disease free seed and resistant variety

2. Seed should be procured from arid area

3. Soak the seed for two hours in streptocycline solution (250 ppm) before sowing

4. Avoid overhead irrigation

5. Spray copper oxychloride @0.25% during the disease development period at 7-10 days interval

Powdery mildew (Erysiphe pisi)

1. Formation of white powdery patches on leaves, stems and pods

2. Perenates through leguminous weeds and flowers viz., Pisum, Meliotus indica, Vicia faba, Lens, Vetches and perennial tree Robinia pseudoacaia

3. Also survive as perithecia on infected palnt debris (dry temperate area)

4. Disease is favoured by dry and high temperature (more then 20°C)

Management

1. Cultural practices like sprinkler irrigation and early sowing

2. Folira spray of fungicides which Sulfex @0.3 % or with Carathane, Bayleton, Topas, Score and Contaf each @ 0.05% at periodic interval of 7-10 days

Enation Mosiac (Penation mosaic virus- PEMV)

1. Early infection cause plant distortion and death before bloom

2. Later infection cause plant stunting, chlorotic flex, leaf and pot distortion and reduced seed size and quality

149

3. PEMB transmitted by several species of aphids in a persistent manner

4. PEMV has wide host range in legumes

Management

1. Use tolerant variety

2. Use insecticides (Metasystox)

Pea Seed borne Mosaic Virus (PSbMV)

1. Symptoms include chlorosis and stunting of the infected plants

2. Leaflets appear narrow and shorten and start rolling downward

3. At later stages plant shows apical malformation in the form of resetting and tendril curling

4. The virus has a wide host range and transmitted through seed and aphids vectors

Management

1. Use of certified seeds

2. Use resistant variety

3. Use insecticides (Metasystox)

References:

Anand, N.Deshpande, A.A. and Ramachander, P.R. 1987. Intra group geometry in Capsicum annuum. Genetica Agraia. 41(4) : 453-460.

Black,L.L., Green, S.K., Hrtman, G.l. and Poulos, J.M.1991. Pepper Diseases a field guide AVRDC. Publication. No. 91-347, 98pp.

Espinosa, J.,Despestre, T. and Camino, V.1991. A new resistant sweet pepper variety. Capsicum-Newsletter. No. 10, 49.

Fadeev, I.N. and Novozhilov, K.V.1987. Integrated Plant Protection. Oxonian Press. Pvt. Ltd. 333 pp.

Merrero, T.A and Gonzalez, B. J. 1985. Reaction of Capsicum annuum cultivars to Xanthomonas vesicatoria. Ciencias-de-la-Agricultura. No.23, 14-19.

Reifschnieder, F.J.B., Café, F.A.C. and Rego, A.M. 1986. Factors affecting expression of Resistance in pepper to blight caused by Phytophtora capsici in screening trials. Plant Pathology. 35: (4) 451-456.

Ullasa, B.A., Rawal, R.D., Sohi, H.S., Singh, D.P. and Joshi, M.C. 1981. Reaction of Sweet pepper genotype to anthracnose, cercospora leaf spot and Powdery mildew. Plant disease 65: 600-601.

150

Disease Management Scenario in Changing Climatic Conditions

Harender Raj Gautam

Department of Plant PathologyDr YS Parmar University of Horticulture & Forestry, Nauni, Solan-173230, HP

The survival of life on earth depends on the blanket of atmosphere that covers the surface of the planet. In the absence of the warming effect created by the blanket of atmosphere around the earth, our planet would be a cold orb with an average temperature

oof – 18 C and would be quite inhospitable for life. Our atmospheric blanket raises the

oaverage temperature to about + 14 C. But, at any given level of concentration of greenhouse gases, the average temperature of the earth settles at a level at which the energy that comes in with solar radiations is balanced by the energy radiated out.

stThroughout the 21 century, India is projected to experience warming above global means. India will also begin to experience more seasonal variation in temperature with more warming in the winters than summers (Christensen et al., 2007). The longevity of heat waves across India have extended in recent years with warmers temperature at nights and hotter days and this trend is expected to continue (Cruz et al., 2007). These heat waves will lead to increased variability in summer monsoon precipitations, with drastic effect on agriculture sector in India.

In developing countries like India, climate change is an additional burden because ecological and socioeconomic systems are already facing pressures from rapid population, industrialization and economic development. India's climate could become warmer under conditions of increased atmospheric carbon dioxide . The average temperature change is predicted to be in the range of 2.33° C to 4.78° C with the doubling in concentrations. Agriculture production is direct dependence on climate change and weather, is one of the widely studied sector in the context of climate change. The

The question whether climate change will cause more devastating plant disease epidemics to occur cannot be answered in general terms. Climate change is not the same as weather change. Climate models predict a gradual rise CO concentration and temperature all over the world, but are not very 2

precise in predicting future changes in local weather conditions. Local weather conditions such as rain, temperature, sunshine and wind in combination with locally adapted plant varieties, cropping systems and soil conditions can maximize food production as long as plant diseases can be controlled. Currently we are able to secure food supplies under these varying conditions. However, all climate models predict that there will be more extreme weather conditions, with more droughts, heavy rainfall, and storms in agricultural production regions. Such extreme weather events will influence where and when disease will occur, and therefore impose severe risks on crop failure.

CO2

possible changes in temperature, precipitation and concentration are expected to significant impact on crop growth. So that overall impact of climate change on worldwide food production is considered to be low to moderate with successful adaptation and adequate irrigation, global agricultural production could be increased due to the doubling of fertilization effect.

Effect of increased CO concentrations on pathogens 2

The concentration of CO in the atmosphere reached 379 ppm in 2005, which 2

exceeds the natural range of values of the past 650,000 years (IPCC, 2007). An increase in CO levels may encourage the production of plant biomass; however, 2

productivity is regulated by water and nutrients availability, competition against weeds and damage by pests and diseases. Consequently, a high concentration of carbohydrates in the host tissue promotes the development of biotrophic fungi such as rust (Chakraborty et al., 2002). Thus, an increase in biomass can modify the microclimate and affect the risk of infection. In general, increased plant density will tend to increase leaf surface wetness duration and regulate temperature, and so make infection by foliar pathogens more likely. Experimental research on the effects of high atmospheric CO concentrations on plant–pathogen interactions has received 2

little attention, and conflicting results have been published. Elevated levels of CO 2

can directly affect the growth of pathogens. Chakraborty et al. (2002), reported that the growth of the germ tube, appressorium and conidium of C. gloeosporioides fungi is slower at high concentrations of CO (700 ppm). Germination rates of conidia on 2

leaves were lower at CO concentrations of 700 ppm than those observed at 350 ppm. 2

However, once the pathogen infects the plant, the fungus quickly develops and achieves sporulation. In contrast, the rate of germination sporulation was greater at high concentrations of CO (700 ppm). In another study Hibberd et al. (1996) 2

evaluated powdery mildew in barley, and found that an acclimation of photosynthesis at elevated CO and an infection-induced reduction in net 2

photosynthesis caused larger reductions in plant growth at elevated CO ; also, the 2

percentage of conidia that progressed to produce colonies was lower in plants grown in high (700 ppm) than in low (350 ppm) and lower percentage of conidia CO2

producing hyphae in 700 ppm , it was due to a higher proportion of the spores being arrested at the appressorial stage. Tiedemann and Firsching (2000) analyzed the direct effects of elevated ozone and carbon dioxide on spring wheat infected with Puccinia recondita f. sp. tritici and reported that ozone damage to leaves is largely dependent on both carbon dioxide concentrations as well as disease. Models can then be used to extrapolate, predict and validate potential impacts. Some authors suggest that elevated CO concentrations and climate change may accelerate plant pathogen 2

CO2

CO2

CO2

CO2

152

evolution, which can affect virulence. Researches in this direction have been carried out. In this regard, Mulherin et al. (2000), evaluated the response of tobacco grown under elevated to inoculation with tobacco mosaic virus (TMV) in two concentration of (360 and 720 ppm) and found that plants grown at 720 ppm produced fewer TMV lesions per leaf versus plants grown at 360 ppm . Eastburn et al. (2010) evaluated the effects of elevated and O on three soybean diseases 3

namely downy mildew (Peronospora manshurica), Septoria (Septoria glycines) and sudden death syndrome (Fusarium virguliforme) and reported that changes in the composition of the atmosphere altered the expression of the disease, and plant responses to the diseases varied considerably. The severity of downy mildew damage was significantly reduced at high levels of . In contrast, high levels of , alone or in combination with high concentrations of O , increased the severity of Septoria 3

glycines. The concentration of and O did not have an effect on sudden death 3

syndrome. The authors concluded that high levels of and O induced changes in 3

the soybean canopy density and leaf age, likely contributed to disease expression modification. Kobayashi et al. (2006) evaluated the effects of elevated concentrations on the interactions between rice, Pyricularia oryzae and Rhizoctonia solani and found that rice plants were more susceptible to injury. Thus, the authors concluded that rice cultivated at sites with high concentrations of may have an increased risk of infection by the above mentioned pathogens.

The effects of an increase in temperature and ultraviolet radiation on pathogens

Due to changes in temperature and precipitation regimes, climate change may alter the growth stage, development rate and pathogenicity of infectious agents, and the physiology and resistance of the host plant (Charkraborty et al., 1998; Charkraborty and Datta, 2003). A change in temperature could directly affect the spread of infectious disease and survival between seasons. Ultraviolet radiation plays an important role in natural regulation of diseases. Evidence suggests that sunlight affects pathogens due to the accumulation of phytoalexins or protective pigments in host tissue. A change in temperature may favour the development of different inactive pathogens, which could induce an epidemic. Increase in temperatures with sufficient soil moisture may increase evapotranspiration resulting in humid microclimate in crop and may lead to incidence of diseases favoured under these conditions (Mina and Sinha, 2008). Temperature is one of the most important factors affecting the occurrence of bacterial diseases such as Ralstonia solanacearum, Acidovorax avenae and Burkholderia glumea. Thus, bacteria could proliferate in areas where temperature-dependent diseases have not been previously observed (Kudela, 2009). As the temperature increases, the duration of winter and the rate of growth and reproduction of pathogens may be modified (Ladányi and

CO2

CO CO2 2

CO2

CO2

CO CO2 2

CO2

CO2

CO2

CO2

153

Horváth, 2010). Similarly, the incidence of vector-borne diseases will be altered. Climate can substantially influence the development and distribution of vectors. Changes may result in geographical distribution, increased overwintering, changes in population growth rates, increases in the number of generations, extension of the development season, changes in crop-pest synchrony of phenology, changes in interspecific interactions and increased risk of invasion by migrant pests. Because of the short life cycles of insects, mobility, reproductive potential, and physiological sensitivity to temperature, even modest climate change will have rapid impacts on the distribution and abundance of vectors. Thus, increase in temperature may be result in high rate of development of insect, obtaining a greater number of insect generations per cycle. Furthermore increase in temperature could determine the distribution of areas favorable for overwintering (Garrett et al., 2006), or even more lethal zones where the insect cannot survive.

Effect of Climate Change on Plant Diseases

The climate influences the incidence as well as temporal and spatial distribution of plant diseases. The main factors that control growth and development of diseases are temperature, light and humidity and water. Similarly, these factors also affect type and condition of host crop. The climate is becoming increasingly extreme and unpredictable and climate change is affecting plants in natural and agricultural ecosystems. Climate change also disrupts and alters the distribution of pests and diseases, which poses a threat to agriculture. Changes in rainfall patterns and temperature can induce severe epidemics in plants because some types of pathogens will tend to favour others. Moreover if these changes cause unfavorable condition for pathogens diseases could be reduced or not present. Severity will depend on the characteristics of each pathogen and its development as a function of environmental factors as well as the magnitude of changes in temperature and wetness in agro-ecological areas. The range of many pathogens is limited by climatic requirements for infection and development. Studies in this order have been carried out and in many cases have been predicted to lead to geographic expansion (Chakraborty et al., 2002; Salinari et al., 2006; Evans et al., 2007). In the presence of susceptible hosts, pathogens with short life cycles, high reproduction rates and effective dispersion mechanisms respond quickly to climate change, resulting in faster adaptation to climatic conditions (Coakley et al., 1999). Harvell et al. (2002) demonstrated that warm winters with high night temperatures facilitate the survival of pathogens, accelerate life cycles of vectors and fungi, and increase sporulation and aerial fungal infection. Moreover, the results of the aforementioned study suggested that the number of pathogens moving northward will increase as increasing temperature makes that previously inclement areas are more conducive.

154

Climate change will also modify host physiology and resistance, and alter the stages and rates of the development of pathogens. There are many reports to corroborate this fact. Eastburn (2010) found that elevated and O3 induced changes CO2

in the soybean canopy density and leaf age. Kobayashi et al. (2006) found increased number of tillers per plant in rice under elevated . New disease complexes may CO2

arise, and some diseases may cease to be economically important. But, pathogens will follow migrating hosts and infect vegetation in natural plant communities not previously exposed to the often more aggressive strains from agricultural crops (Mina and Sinha, 2008). Evans et al. (2007) conducted a study in the UK to assess the effects of climate change on Phoma on oilseed rape (Leptosphaeria maculans). A model of the prognosis of the disease was used in combination with a climate change model predicting UK temperature and rainfall under emission scenarios for the 2020 and 2050's. It was also found that epidemics will not only increase in severity but also spread northwards by 2020's. Such predictions can be used to guide policy and practice in adapting to the effects of climate change on food security and wildlife. Salinari et al. (2006) used two climate change models to simulate future scenarios of downy mildew on grapevine (Plasmopara viticola). This empirical model predicted an increase of the disease pressure in each decade and more severe epidemics were direct consequence of more favorable air temperatures and rainfall reduction conditions during the months of May and June. The simulation analysis suggests that the impact of increased temperatures on enhancing disease pressure exceeded the limiting effect of reduced rainfall, and from a biological point of view, this result can be explained by considering that temperature and wetness act together on the pathogen. Thus, the production of grapes in northwestern Italy would decrease. Kocmánková et al. (2007) conducted a study where a model was developed allowing the risk assessment of early outbreaks or increases in the intensity of Potato late blight (Phytophthora infestans) under the climate change in central Europe. Under all climate change scenarios a marked change was noted in the infestation pressure of evaluated disease and in the higher number of favorable days for Potato late blight outbreak. The results show the shift of the infestation pressure to the beginning of the year and describe an increasing trend of critical number reaching to the detection of the first P. infestans occurrence for 2025 and 2050.

Conclusion

Climate change is an important phenomenon that is surely going to affect agricultural production. The present knowledge in the area and also by simulating various models in important pathogen-host combinations, we can prepare ourselves to counter the threat on our crop production and productivity. It is presumed that global warming may modify areas affected by pests and diseases and studies must be

CO2

155

performed to assess pest and disease stages under the effects of climate change to determine the magnitude of disease and identify measures to minimize the risk of infection. Exposure to altered atmospheric conditions can modify fungal disease expression. Studies had shown that exposure at elevated increases disease

incidence or severity in some cases but in other cases decreased. So increase or decrease disease will be in function of the host and pathogen. Hence the importance of conducting studies on main crops and major disease for each region. Temperature is one of the main factors in conjunction with the rain to determine the incidence and severity of disease, but the effect could be positive and negative. Disease risk analyses based on host-pathogen interactions should be performed, and research on host response and adaptation should be conducted to understand how an imminent change in the climate could affect plant diseases.

References:

Chakraborty S, Datta S (2003) How will plant pathogens adapt to host plant resistance at elevated under a changing climate? New Phytol 159:733-742CO2

Chakraborty S, Murray G, White N (2002). Potential impact of climate change on plant diseases of economic significance to Australia. Australas. Plant. Pathol. 27: 15-35.

Coakley SM, Scherm H, Chakraborty S (1999). Climate Change and Plant Disease. Annu. Rev. Phytopathol. 37: 399-426.

Cruz R V, Harasawa H, Lal M, Wu S, Anokhin Y, Punsalmaa B, Honda Y, Jafari M, Li C and Huu Ninh N. 2007. Asia. Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Parry M L, Canziani O F, Palutikof J P, van der Linden P J and Hanson C E (eds). Cambridge University Press. Cambridge, UK. pp. 469 – 506.

Christensen J H, Hewitson B, Busuioc A, Chen A, Gao X, Held I, Jones R, Kolli R K, Kwon W-T, Laprise R, Magaña Rueda V, Mearns L, Menéndez C G, Räisänen J, Rinke A, Sarr A and Whetton P. 2007. Regional Climate Projections. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt K B, Tignor M and Miller H L (eds)]. Cambridge University Press. Cambridge, United Kingdom and New York, NY, USA.

CO2

156

Eastburn DM, Degennaro MM, Delucia EH, Dermody O, Mcelrone AJ (2010). Elevated atmospheric carbon dioxide and ozone alter soybean diseases at SoyFACE. Global Change Biol. 16: 320-330.

Evans N, Baierl A, Semenov AM, Gladders P, Fitt BDL (2007). Range and severity of a plant disease increased by global warming. J. R. Soc. Interface. 5: 525-531.

Garrett, KA, Dendy SP, Frank EE, Rouse MN, Travers SE (2006). Climate change effects on plant disease: genomes to ecosystems. Annu. Rev. Phytopathol. 44: 489-509.

Gautam, H.R. 2009. Challenges of climate change and bio-energy to world food security. Open Learning (July- December): 49-51.

Gautam, H.R. 2009. Effect of climate change on rural India. Kurukshetra 57 (9): 3-5.

Gautam, H.R. and M.L.Bhardwaj 2011. Better practices for sustainable agricultural production and better environment. Kurukshetra 59 (9): 3-7.

Harvell HC, Mitchell CE, Ward JR, Altizer S, Dobson AP, Ostfeld RS, Samuel MD (2002). Climate warming and disease risks for terrestrial and marine biota. Science, 296: 2158-2162.

Hibberd JM, Whitbread R, Farrar JF (1996). Effect of elevated concentrations of CO2

on infection of barley by Erysiphe graminis. Physiol. Mol. Plant Pathol. 48: 37-53.

Kobayashi T, Ishiguro K, Nakajima T, Kim HY, Okada M, Kobayashi K (2006). Effects of elevated atmospheric concentration on the infection of rice blast CO2

and sheath blight. Phytopathology, 96: 425-431.

Kocmánková E, Žalud Z, Trnka M, Semerádová D, Dubrovský M, Možný M, Juroch J (2007). The climate niches of colorado potato beetle and potato late blight in central Europe in 2050. In: MendelNet'07 Agro (Proceedings of International Ph.D. Students Conference). Mendel university of agriculture and forestry brno.

Kudela V (2009). Potential Impact of Climate Change on Geographic Distribution of Plant Pathogenic Bacteria in Central Europe. Plant Protect. Sci. 45: S27-S32.

Ladányi M, Horváth L (2010). A review of the potential climate change impact on insect populations – general and agricultural aspects. Appl. Ecol. Environ. Res. 8(2): 143-152.

Mina U, Sinha P (2008). Effects of Climate Change on Plant Pathogens. Environ. News. 14(4): 6-10.

157

Mulherin KM, Karowe DN, Enyedi AJ (2000). Effects of elevated carbon Yáñez-López et al. 2427 dioxide on plant-pathogen interactions. In plant Biology 2000. Plant Biology Meeting. Symposium Elevated . Abstract number 368. San CO2

Diego, Ca. USA.

Salinari F, Giosue S, Tubiello FN, Rettori A, Rossi V, Spanna F, Rosenzweig C, Gullino ML (2006). Downy mildew (Plasmopara viticola) epidemics on grapevine under climate change. Glob. Change Biol. 12: 1299-1307.

Tiedemann AV, Firsching KH (2000). Interactive effects of elevated ozone and carbon dioxide on growth and yield of leaf rust-infected versus non-infected wheat. Environ. Pollut. 108: 357-363.

158

Eco-friendly Techniques for Management of Diseases in Spice Crops

Meenu Gupta

Department of Vegetable Science,Dr YS Parmar University of Horticulture & Forestry, Nauni, Solan (HP) 173 230

Economic losses arising from crop diseases caused by plant pathogens are principally associated with yield reductions. However, crop quality and safety may also be adversely affected, undermining both consumer confidence and profitability to the producer. Hence protection of plants from pathogens is the preoccupation of agricultural scientist around the world and it is the unifying goal of plant pathology to control plant disease and chemicals play a major role in accomplishing that goal in contemporary agricultural production. Pesticides which are incessantly used on plants to manage these disease cause serious damage to agricultural and natural ecosystems. Thus, there is a need to curtail pesticide use and reduce the environmental impacts of pesticides.

In the early stages of development of agriculture, farmers had realized from observation and experience that crops look sick when grown on the same land year after year, when land was not left fallow, or when there was excess of moisture and other mismanagement. By proper adjustment of practices in the cultivation of the crop they had been avoiding these situations. However, for effective control of plant diseases through adjustment of crop management procedures we have yet to learn more about the ecology of the pathogens. Successful use of cultural practices for disease control can be made only when a complete knowledge of nature of the pathogen and its behavior in different conditions of the environment-climate, cropping system etc. is available. Although resistant varieties and fungicides are very important tools in management of diseases, their efficacy can be further improved and they can be made more lasting and economical by modification of cultural practices. Often cultural practices are the only feasible methods of disease control especially in spice crops where resistant varieties are not known. Under this concept, all possible modes of plant disease control methods are integrated to minimize the excessive use of synthetic pesticides. Exploitation of naturally available chemicals from plants, which retards the reproduction of undesirable microorganisms, would be a more realistic and ecologically sound method for plant protection and will play a prominent role in the development of future commercial pesticides for crop protection strategies, with special reference to the management of diseases in spice crops.

Eco friendly techniques of disease management

I. Cultural management

i) Infected host eradication

Certain pathogens of annual spice crops overwinters only or mainly in perennial wild plants. Eradication of host in which the pathogen overwinters is sometimes enough to eliminate completely or to reduce drastically the amount of inoculum that can cause infection the following season. It is routinely carried out in nurseries, greenhouses, and fields.

ii) Crop rotation

Soil borne pathogens that infect plants of one or few species or even families of plants can sometimes be reduced in the soil by planting non-host crops for 3 or 4 years. In this case, crop rotation can reduce population of pathogen (e.g. Verticillium). Ginger can be rotated with cruciferous crops.

iii) Sanitation

Sanitation consists of all activities aimed at eliminating or reducing the amount of inoculum present in a plant, field or a warehouse and at preventing the spread of the pathogen to other healthy plants and plant products. Thus, ploughing under infected plants after harvest, such as leftover infected fruit, rhizomes or leaves, helps cover the inoculum with soil and speed up its disintegration and concurrent destruction of most pathogens carried in or on them.

iv) Creating conditions unfavourable for the pathogen

In the production of many crops, particularly containerized stock, using decomposed tree bark in the planting medium has resulted in the successful control of diseases caused by several soil-borne pathogens. e.g. Phytophthora, Phythium and Thielaviopsis causing root rots, Rhizoctonia causing damping off and crown rot, Fusarium causing wilt and nematode diseases of several spice crops.

v) Evasion or avoidance of the pathogen

For several spice crop diseases, control depends on attempts to evade pathogens. For example, chilli anthracnose, caused by the fungus Colletotrichum capsici, and the bacterial blight of coriander, caused by bacteria Pseudomonas syringae are transmitted through the seed. They can be successfully controlled by using disease free seed and seed treatments.

160

vi) Use of pathogen free material/seeds

Seed may carry internally one or a few fungi such as those causing yellows and soft rots, certain bacteria causing bacterial wilts, spots and blights and certain viruses.

II. Physical and legislative management

The physical agents used most commonly in controlling plant diseases are temperature (high or low), dry air, unfavourable light wave lengths and the various types of radiations. With some crops, cultivation in glass or plastic green houses provides physical barriers to pathogens and their vectors and in that way protects the crop from some diseases.

i) Soil sterilization by heat

Soil can be sterilized in green houses, and sometimes in seed beds and cold frames, by the heat carried in live or aerated steam or hot water. The soil is steam sterilized either in special containers (soil sterilizers), into which steam is supplied under pressure, or on the greenhouse benches, in which case steam is piped into and is allowed to diffuse through the soil. At about 50ºC, nematodes, some oomycetes, and other water moulds are killed whereas most plant pathogenic fungi and bacteria, along with some worms, slugs, centipedes, are usually killed at temperatures between 60 and 72ºC.

ii) Soil solarization:

When clear polythene sheet is placed over moist soil during sunny summer days, the temperature at the top 5 cm of soil may reach as high as 52ºC compare to a maximum of 37ºC in unmulched soil. If sunny weather continues for several days or weeks, the increased soil temperature from solar heat, known as solarization, inactivates or kills many soil borne pathogens, viz., fungi, nematodes, and bacteria near soil surface, thereby reducing the inoculum and the potential for disease.

iii) Hot water treatment of propagating organs:

Hot water treatment of certain seeds, bulbs, rhizomes and nursery stock is used to kill any pathogens with which they are infected or which may be present in seed coats, bulbs, scales, and so on, or which may be present in external surfaces or wounds.

oTreatment of ginger rhizomes at 45 C against rhizome rot for 30 minutes has been recommended against rhizome rot (Fusarium oxysporum) followed by streptocycline dip (100 ppm) for 30 minutes.

161

iv) Disease control by refrigeration

Refrigeration is probably the most widely used and the most effective method of controlling post harvest diseases of fleshy plant products. Although low temperature at or slightly above the freezing point do not kill any of the pathogen that may be on or in the plant tissues, they do inhibit or greatly retard the growth and activities of all such pathogens, thereby reducing the spread of existing infection and the initiation of new ones.

III. Biological management

Biological control of plant pathogens refers to the total or partial destruction of pathogen population by other organisms. It occurs routinely in nature but manipulations by human being have resulted in enhanced benefits. It is achieved by suppressive soils, reducing amount of inoculum through antagonistic microorganisms or by direct protection by biological control agents.

i) Suppressive soils

Many soil borne pathogens, such as Fusarium oxysporum (causing yellows), Pythium spp. (causing soft rot) develop well and cause severe diseases in some soils, known as conducive soils, whereas they develop much less and cause much milder diseases in other soils, known as suppressive soils. Many kinds of antagonistic microorganisms have been found to increase in suppressive soils; most commonly, pathogen and disease suppression has been shown to be caused by fungi, such as Trichoderma, Penicillium, and Sporidesmium, or by bacteria belonging to the genera Pseudomonas, Bacillus, and Streptomyces.

ii) Reducing amount of inoculum through antagonistic microorganisms

a) Control of soil borne pathogens: Several non-plant pathogenic oomycetes and fungi, including some chytridiomycetes and hyphomycetes, and some pseudomonad and actinomycetous bacteria infect the resting spores of several plant pathogenic fungi. Among the most common mycoparasitic fungi are Trichoderma sp., mainly T. harzianum. It parasitizes mycelia of Rhizoctonia and Sclerotium, and inhibits the growth of many oomycetes such as Pythium, Phythophthora, and other fungi, e.g., Fusarium

b) Control of aerial pathogens: Many fungi have been shown to antagonize and inhibit numerous fungal pathogens of aerial plant parts. For example,Ampelomyces quisqualis parasitizes powdery mildew fungi. Darluca filum, and Verticillium lecanii parasitizes several rust.

162

c) Control through trap plants: If a few rows of rye, corn, or other tall plants are planted around a field of peppers or ginger many of the incoming aphids carrying viruses that attack the peppers, and ginger will stop and feed on the peripheral taller rows of rye or corn. Trap plants are also used against nematodes which are sedentary endo- or ecto-parasites. For example, Crotalaria plants trap the juveniles of root- knot nematodes.

d) Control through antagonistic plants: Plants such as asparagus and marigold are antagonistic to nematodes because they release substances in the soil that are toxic to several plant parasitic nematodes.

IV. Chemical management

Chemical pesticides have been used generally in plant protection programmes to overcome the diseases caused by various pathogens. Normally, chemical treatments are aimed to eradicate the general inoculum before it comes in contact with the plant hosts. In eco-friendly management of diseases, new and safer fungicides like elemental form of copper and sulphur are used. Depending upon the pathogens they affect, they may be classified as fungicides, bactericides, nematicides, viricides etc. Out of these, some chemicals are broad-spectrum and they are toxic to all pathogens. Most of the chemicals used in plant protection are foliar and are used on the aboveground parts of the plants. Some of them are soil disinfectants, and some are used as protectants on seed, tubers, culms etc. There are some of the chemicals which are used for curing diseases and are called curative or chemotherapeutants.

Types of chemical compounds used for plant disease control

A. Inorganic chemicals

i) Copper compounds

The Bordeaux mixture is the product reaction of copper sulphate and calcium hydroxide. It controls diseases like bacterial leaf spot, blights, anthracnose, downy mildews and cankers. Phytotoxicity of Bordeaux mixture can be reduced by increasing the ratio of hydrated lime to the copper sulphate.

ii) Inorganic sulphur:

Elemental sulphur (oldest fungicide) is used as a dust, wettable powder, paste or liquid sulphur. It controls powdery mildews, certain rusts, leaf blights and fruit rots. It is available in trade names like Wettasul, Cosavet etc.

163

iii) Carbonate compounds:

Sodium carbonate as well as bicarbonate salts of ammonium, potassium and lithium plus 1 per cent superfine oil are inhibitory and fungicidal to the powdery mildew fungi, gray mould etc.

iv) Phosphate and phosphonate compound:

Spraying cucurbit with either of monopotassium phosphate or dipotassium phosphate gives satisfactory control of powdery mildew disease.

B. Systemic Fungicides: among systemic fungicides, traizoles and strobilurins are used as these are comparatively safer fungicides and have low toxic residues.

i) Triazoles

Triazoles include triadimefon, bitertanol, difenconazole, propiconazole, myclobutanil, cyperconazole, tebuconazole etc. these show long protective and curative activity against broad-spectrum of foliar, root and seedling diseases like leaf spots, blights, powdery mildews and rusts caused by fungi. These can be applied as foliar as well as seed and soil treatments.

ii) Strobilurins or QoI fungicides

These are the new generation and important fungicides. The most important are azoxystrobin, trifloxystrobin and kresoxim methyl. These strobilurins can be used against cucurbit diseases.

V. Host resistance

Use of resistant varieties in crop cultivation provides undoubtedly the most cost-effective, logistically the easiest, and also the safest of all the methods used for disease control. Both from the economic point of view and the possible health hazards involved in some of the methods used for disease control, this can probably termed as the “painless method”. This approach costs little to the farmer and is, therefore, suitable for the developing countries like India. Use of resistant varieties not only reduces environment pollution and eliminates hazards to human health, but also checks disease epidemics and thus helps to maintain the biological balance in the ecosystem.

For many diseases like the vascular wilts and those caused by viruses, which are difficult to control effectively by some other means, and others like rusts, powdery mildews, and root rots, which do not appear to be economically practical to be controlled by other methods, the cultivation of resistant varieties provides the only means of producing acceptable yields without

164

using toxic compounds. Several other kinds of fungal diseases and also many others caused by bacteria, nematodes, and viruses are best controlled by this approach.

Some examples of resistant varieties

VI. Integrated Disease Management

Integrated disease management (IDM) came under focus in 1960's when chemicals especially, fungicides and insecticides came under the attack from environmentalists due to the overuse of chemicals that created the problems of environmental pollution, chemical residues in food stuff, land, water and air, and the associated health hazards. Thus, it focused on the other methods of disease control. It involved cultural, biological, epidemiological and alternative means to achieve the disease control.

Integrated disease management can be defined as the “disease management system that in the context of associated environment and population dymamics of microorganisms, utilizes all suitable techniques and method in a manner as compatible as possible and maintains the disease below economic level”. In general, it is the integration of all possible and suitable management techniques for the control of diseases.

Integrated disease management in ginger

1. Select healthy and disease free seed.

2. Treat the seed for one hour in a mixture of Dithane M-45 (0.25%) + carbendazim (0.1%) and shade dry for 48 hours.

3. Ensure proper drainage in the field.

Crop Variety Disease Ginger Himgiri Ttolerant to rhizome rot Turmeric Suguna and Sudarshan Tolerant to rhizome rot

IISR Kedaram Resistant to leaf blotch IISR AJleppey Supreme Resistant to leaf blotch

Chilli Punjab Lal Viruses Black pepper IISR Shakti Tolerant to Phytophthora

IISR Thevam Field tolerant to Phytophthora Coriander CO-3 Wilt and grey mold Fenugreek CO-2 Root rot Cardamom IISR Avinash Rhizome rot tolerant IISR Vijetha Resistant to Katte

165

4. Destroy the infected parts and drench the infected plants with copper oxychloride (0.3%).

5. Spray copper oxychloride (0.3%) against Phyllosticta leaf spot at an interval of 10 days.

6. Follow crop rotation for five years.

References:

H. Panda. 2010. Handbook on Spices and Condiments (Cultivation, Processing and Extraction).

E.A. Weiss. 2002. Spice crops. CabiPublishing. 399p.

S.L. Godara, B.B.S. Kapoor, B.S. Rathore. 2010. Disease management of spice crops. DK Agencies Pvt. Ltd.

Asia Pacific Business Press Inc. 640p.

166

Common name

Scientific name

Order

Family

Potato tuber moth Phthorimaea operculella Lepidoptera Gelechiidae

White grub Brahmina coriacea, B. cirnicolli, Coleoptera Scarabaeidae

Hadda beetles Henosepilachna vigintioctopunctata Coleoptera Coccinellidae

Cut worms Agrotis spp. Lepidoptera Noctuidae Aphids

Myzus persicae

and Aphis gossypii

Homoptera

Aphididae

Integrated Pest Management in Solanceous and Leguminous Vegetable Crops

KC Sharma

Department of EntomologyDr YS Parmar University of Horticulture and Forestry, Nauni, Solan-173 230 HP

Integrated Pest Management (IPM): It is the blending of all the suitable control measures against the pest species in as compatible manner as possible so as to avoid the pests population in reaching the economic injury level.

Components of IPM:

1. Physical methods

2. Mechanical methods

3. Cultural control

4. Use of bio pesticides

5. Regulatory methods

6. Genetic control

7. Chemical control

The details of Solanceous and Leguminous crops are given below:

i) Solanceous vegetable crops: Potato, Tomato, Brinjal, Capsicum, Chilies

ii) Leguminous vegetable crops: Pea, Beans

The insect pests attacking these vegetable crops are tabulated under the following heads:

i) Solanceous crops: Potato, Tomato, Brinjal, Capsicum

Insect pests of potato

Common name Scientific name Order Family

Cut worm Agrotis segetum Lepidoptera Noctuidae

Fruit borer Helicoverpa armigera Lepidoptera Noctuidae

Greenhouse whitefly Trialeurodes vaporariorum Homoptera Aleyrodidae

Serpentine leafminer Liriomyza trifolii Diptera Agromyzidae

Phytophagous mite Tetranychus urticae Acari Tetranychidae

Fruit fly Bactrocera tau Diptera Agromyzidae

Insect pests of Tomato

Insect pests of Brinjal

Insect pests of Capsicum

Common name Scientific name Order Family

Brinjal shoot & fruit

borer

Leucinodes orbonalis Lepidoptera Phycitidae

Brinjal stem borer Euzophera perticella Lepidoptera Phycitidae

Brinjal lace wing bug Urentius sentis , U. hystricellus

Hemiptera Tingidae

Leaf hoppers

Amrasca biguttula biguttula

Hemiptera

Cicadellidae

Mite Tetranychus sp.

Acari

Tetranychidae

Common name Scientific name Order Family

Phytophagous mite Tetranychus urticae Acari Tetranychidae

Aphid Myzus persicae Sulzer Homoptera Aphididae

Greenhouse whitefly Trialeurodes vaporariorum Homoptera Aleyrodidae

168

Common name Scientific name Order Family

Bihar hairy caterpillar Spilartia obliqua Lepidopera Arctidae

Insect pests of chilies

Leguminous crops: Pea, French bean

Insect pests of Pea

Insect pests of beans

The management practices given below are the General Management Practices, thus necessarily do not reflect the university recommendations.

Insect pests of potato:

Potato tuber moth:

Damage: The larva of the potato tuber moth mines into the leaf, eventually killing the terminal section of the plant. Management: Plant tubers slightly deeper (10cm) and follow proper earthing up

i) Harvested potatoes should be lifted to cold stores immediately, however if cold store facilities are not available, only healthy tubers should be stored.

Common name Scientific name Order Family

Green peach aphid Myzus persicae Homoptera Aphididae

Greenhousse whitefly Trialeurodes vaporariorum Homoptera Aleyrodidae

Tobacco caterpillar Spodoptera litura Lepidoptera Noctuidae

Common name Scientific name Order Family

Pea leafminer Chromatomyia horticola Diptera Agromyzidae

Pea pod borer Helicoverpa armigera Lepidoptera Nocuidae

Eteilla zinckenella Lepidoptera Phycitidae

Semilooper Thysanoplusia orichalcea Lepidoptera Noctuidae

Pea blue butterfly Lampides boeticus Lepidoptera Lycaenidae

Pea thrips Caliothrips indicus Thysanoptera Thripidae

169

ii) Mass trapping of adults with sex pheromones.

iii) Spray of crop with acephate (0.05%)

iv) In stores dusting the tubers with 5% malathion and alternatively, dipping of tubers before storage with 0.0028% deltamethrin

White grub:

Damage: Initially young grubs feed on mother tuber, roots of developing potato plants. After tuber formation, the older second instar and third instar grubs feed on the underground potato tubers.

Management:

i) Apply well rottened FYM.

ii) Deep ploughing immediately after harvest and collection and killing of grubs.

iii) Use of light trap to collect adult beetles during May-June.

iv) Application of phorate10G (25-30Kg/ha) near plant base at the time of earthing up or drenching of ridges with chlorpyriphos 20 EC.

Insect pests of tomato

Cutworm

Damage: Soon after transplanting, larvae attack the tomato seedling.

Management:

i) Use of sex pheromone traps for monitoring.

ii) While preparing field mix follidol M-2 dust 5% @ 1½ -2 kg/bigha.

iii) Use well rottened FYM.

iv) Drenching with chlorpyriphos (0.04%) should be done in the basin of the plants.

Tomato fruit borer:

Damage: Larva feeds on foliage, flower buds and flowers for some time and later enters into the developing fruits

Management:

i) Use of sex pheromone for monitoring and early detection.

170

ii) Releasing two species of egg parasitoids, viz., Trichogramma brasiliensis and T. pretiosum at weekly intervals from flower initiation with 5-6 releases. Both the species of egg parasitoids at 2.5 lakh adults/ha can effectively check the population of H. armigera.

iii) Planting of marigold as trap crop.

iv) Spray of HaNPV @ 250LE/ha

v) It can also be managed by spray of cypermethrin (0.0075%) or deltamethrin (0.0025%) at 15-day interval.

Serpentine leafminer:

Damage: Damage is caused by larva which feeds in the tissues in between the layer of the leaf. It makes galleries which are prominent on leaves.

Management:

i) Use of neem seeed kernel extract @ 4%.

ii) Judicious use of nitrogenous fertilizers.

iii) The pest can be managed by spraying of deltamethrin (0.0056%) followed by another spray of triazophos (0.15%) at 15-day interval.

Greenhouse whitefly:

Damage: Nymphs and adults cause damage by sucking sap from foliage resulting in yellowing of leaves which fade and dry away.

Management:

i) Install yellow traps for monitoring.

ii) Neem formulations (@1-3 ml/lt of water can also be used against this pest.

iii) As soon as the pest appears, spray the crop with imidacloprid (0.01%) or acetamiprid (0.02%).

Red spider mite:

Damage: Nymphs and adults cause damage by feeding on underside of leaves due to which leaves show characteristics blotching and bronzing.

Management:

i) Destruction of infested plant parts in the initial stage of infestation.

ii) Use pongamia oil @ 1ml/10 lts

171

iii) Use neem seed kernel extract @ 5-6%

iv) Among bio control agents, phytseiid mite, Amblyseius tetranychvorous can be mass reared on caster pollen grains and released when the spider mite population begins to appear on the crop.

v) Spray of ethion (0.05%), fenazquin (0.0025%), propergite (0.057%) malathion (0.05%) or dicofol (0.05%).

Fruit fly: Bacrocera tau

Damage: Damage is caused by larvae which feed inside the tomato fruit on fruit pulp due to which the fruit is rendered unfit for human consumption.

Management:

i) All the infested fruits that fall to the ground should be collected and buried deep (at least 2 feet) in the soil followed by drenching malathion to avoid the escape of emerging adults.

ii) Bagging of fruits in smaller areas.

iii) Use lure to attract male flies for monitoring and mass trapping.

iv) Fruit flies can be managed by applying bait spray which consists of malathion (10ml), gur (50 grams) and water (5 lts).

Insect pests of brinjal:

Brinjal hadda beetle:

Damage: The damage is caused by the beetles and the grubs which feed on leaves.

Management:

i) Collection and destruction of various stages of the pest.

ii) The pest can be controlled by spraying the crop with malathion (0.05%) or carbaryl (0.1%).

Brinjal shoot and fruit borer:

Damage: It damages the crop from seedling stage till the harvest.

Management:

i) Use pheromone traps.

ii) Application of neem based pesticides.

iii) Same crop should not be harvested in the same field and destruction of infested shoots along with the larvae at 15 days interval.

172

iv) Use sex pheromones @ 100/ ha (10x10m)

v) Spray fenvalerate (0.01%) or carbaryl (0.1%)

Jassid: Damage is caused by nymphs and adults which suck sap from leaves.

Management:

i) Apply malathion (0.05%)

ii) Predators, like Chrysoperla sp., spiders etc. predate upon nymphs and adults of this pest.

Insect pests of pea:

Pea leafminer

Damage: More serious damage is caused by larvae.

Management:

i) Pluck the older leaves and burn.

ii) Application of oxy-demeton methyl (0.025%) or dichlorvos (0.04%) during the second week of February help in reducing the population of this pest.

Pea pod borer:

Damage: Damage is caused by caterpillars which in the earlier stages feed on leaves and later on they enter into the pods of pea.

Management:

i) Apply carbaryl (0.1%) or deltamethrin and repeat the spray after 15-day intervals.

Pea thrips, Caliothrips spp.

Damage: Damage is caused by adults and nymphs which lacerate the surface and suck the sap from leaves and flowers.

Management:

i) Monitor thrips adults and larvae by branch beating or shaking foliage or flowers onto a sheet of paper or a beating tray or sheet. Adult thrips can also be monitored using bright yellow sticky traps.

ii) Neem based pesticides can be somewhat effective for temporary reduction of thrips.

iii) Apply lambda cyhaothrin (0.004%) or cypermethrin (0.0075%).

173

Insect pests of French bean

Black bean bug:

Damage: Both adults and nymphs suck sap usually from lower side surface of leaves. As a result of sap sucking, the chlorophyll content is reduced.

Management:

i) During rainy season, predatory spiders feed on nymphs of this pest.

ii) Before flower initiation and pod formation stage, spray the crop with oxy-demeton methyl (0.025%) or dimethoate (0.03%).

iii) Rainy season crops are more prone to the damage by this pest so the early sowing can help in protection of crop.

Blister beetle:

Damage: Damage is caused by adults which feed on foliage, flowers and developing pods.

Management:

The beetles can be managed by spraying carbaryl (0.1%) or deltamethrin (0.0028%).

Refrences

Sharma, KC, Usha Chuhan, and Verma AK. 2004. Insect pests of vegetable crops: Identification and management manual

Atwal, AS and Dhaliwal. 2009. Agricultural pests of South Asia and their management.

174

Judicious Use of Pesticides to Lower Residue in Vegetable Production

RS Chandel, ID Sharma and SK Patyal

Department of Entomology and ApicultureDr YS Parmar University of Horticulture & Forestry, Nauni-173 230 Solan, HP

Vegetables are typically associated with good nutrition and fresh produce, in particular, is often thought of as healthy. However, media attention related to contamination of fresh fruits and vegetables with pesticides has heightened consumer awareness for having safe food. The frequently asked questions like 'Are all vegetables and fruits I purchase from market contaminated with pesticide residues? Am I being exposed to pesticide residues by eating fruits and vegetables? And above all consideration of pesticides as only 'Sarva Roga Nirvani'- i.e. A cure of all crop ailments?

Pesticides used to control the pests are toxic in nature and are equally harmful to human beings if applied injudiciously. The over, mis and unapproved use of chemicals have become most disturbing environmental issues, today. These have been presented as the main culprit in the agriculture production scenario, causing hazards to human health and the surrounding environment. Despite the fact, it is also true that pesticides have played an important role in increasing the crop productivity by protecting them from insect-pests and diseases. Hence, they still continued to be an important input for crop health, hygiene and increasing the productivity. However, ignorance causes many farmers to use more than the recommended amount in the hope that it will benefit the crops more.

Out of the 228 pesticides registered in the country, 85 technical grade pesticides are manufactured in India having approx. demand of 90,000 MT per

thannum. India's pesticide industry is largest in the Asia and 12 largest in the world. The major demand is in cotton (45%) followed by rice (22%), plantation crops (7%), vegetables (6%), wheat (4%), pulses (4%) and others (9%). Pesticide production and use in the country shows a different pattern from global trends–insecticide use is around 75% in the country, compared to 32% in the world. Herbicide use is only 12% in the country while worldwide, consumption is 47%. Similarly, while carbamate and synthetic pyrethroid compounds are used the most globally (45% together), in India, organophosphates constitute 50% of the consumption. Similarly, bio-pesticides are used only upto 1% amongst all pesticides in India, while worldwide, it is 12%.

With the increase in demand for vegetables round the year vis-a-vis cultivated area to meet the growing demand for domestic as well as export market, the use of pesticides on these crops has also increased to manage the menace of various insect-pests, thus started affecting man and his environment (Jayaraj and Ignacimuthu, 2005). Though, the importance of IPM in sustainable agriculture has been well recognized, very little is being adopted at the field level (Jayaraj, 2002). The traders dealing with different chemicals being used on different vegetables and other food commodities have further exaggerated the problem by supplying different unauthorized and non-recommended chemicals to farmers by ensuring better qualitative and quantitative hike in their produce.

Residue free crop production

Safe vegetable production is a concept that it will not cause harm to the consumer when it is taken as raw or prepared/consumed according to its intended use. It includes production, post harvest handling and storage of vegetables in a way that prevent the entry of pesticide residues to human through their consumption. The share of our country in the global export basket is less than 3% due to several key issues which require attention. These include lack of technical skill and equipments while applying pesticides, lack of updated standards, an absence of a responsive crop monitoring system and the lack of awareness of safety and quality control issues on the part of farmers and traders in the organized and unorganized marketing system. Three developments have contributed significantly to the increase in both, the

stquantity and quality of vegetable moving in national and international trade. The 1 has been the increase in life style of general consumers within the country, the dramatical increase in the number of countries, especially developing countries

rdinvolved in production of vegetables for export and 3 one is internatiolization of food taste and habits.

Hence, the demand for pesticide free produce can be achieved by managing pest population not only by using insecticides alone but also by incorporating other methods in the IPM module for each crop against each pest. The various techniques for managing pest population can be grouped in the following ways:

1. Physical methods: These methods aim to reduce the pest's population by using devices which affect them physically or alter their physiological environment.

a. Cold treatment: Cold treatment in some vegetables is lethal to the harboring 0insect-pests. A temperature of 10 C for several days kills fruit fly larvae.

Similarly cold storage of potato helps in escaping potato tuber moth.0

b. Super heating: A temperature of 50-55 C kills almost all the stages of insects. Super heating can be successfully used against the larvae of fruit flies.

176

2. Mechanical methods: The reduction of insect population by manual devices is called mechanical method of pest control. It involves:

a. Hand picking: Some species of insects which are large and conspicuous can be removed from the plant by hand or by crushing on the plant part.

b. Trapping: Trapping of insect pests attacking vegetable crops can be done by using various traps viz. sticky traps, light traps, bait traps, pheromone traps etc.

3. Cultural methods: Cultural practices are among the oldest techniques used fro insect pest suppression in traditional agriculture system. These methods consist of all the agronomic practices which are used to reduce the pest population and include those methods of planting, growing and harvesting a crop will prevent or lessen insect damage. It includes various practices as: tillage, intercropping, mulching, fertilization, use of trap crops, destruction of refuges, time of planting and harvesting, flooding and irrigation, crop rotation.

4. Utilization of natural enemies: The use of natural enemies against the insect pests is one of the useful methods for safe vegetable production. These include parasitoids, parasites and predators. Mostly insects parasitic upon other insects are protelean parasites i.e. they are parasitic only in their immature stages and lead free lives as adults. They unusually consume all or most of the hosts body and then pupate either within or external to the host. A predator is free living organism which kills its prey and requires more than one prey to complete its development. Among insects, several species of lace wings, lady beetles, mantids and syrphids are good examples of predators of insects. Similarly, bacteria, fungi, viruses etc. have been recognized as the important pathogens for the management of various pests.

5. Safe use of pesticides: Injudicious use of chemical pesticides have resulted in the development of resistance in pests, resurgence of target and non-target pests, destruction of beneficial organisms like honeybees, pollinators, parasitoids, predators, etc., and residues in food, fodder and feeds. Use of unapproved pesticides has been emerged as one of the current issues for having pesticide contamination in fresh produce. It has been observed that farmers purchase one or more recommended pesticides to be used on crops. However, for other crops he is growing, the same pesticide is being used by them. This situation leaves harmful residues due to lack of dose recommendations and safe waiting periods on those crops.

Pesticide consumption: The consumption of pesticides for pest control in agriculture picked up after the introduction of high yielding varieties in 1966-67. The total amount of pesticides used in the country increased from 154 metric tones in 1953-54 to nearly than 84,095 metric tones in 1993-94 and rose nearly to 100,000 metric tones by the year 2000. But in view of the ban on DDT, HCH, aldrin etc, high potency (and consequently lower required dosages) of new insecticides especially

177

synthetic pyrethroids and high priority being accorded to IPM, the pesticides consumption has shown a decreasing trend (41350 MT) during the year 2004-05 (Anonymous, 2008).

Residues in different commodities: The leading chemical used in India during 1995-96 was HCH (BHC), followed by malathion, methyl parathion, endosulfan, carbaryl and dimethoate. During 1999-2000, monocrotophos was the top insecticide followed by endosulfan, malathion and methyl parathion. Among fungicides, consumption of mancozeb was the highest followed by sulphur compounds, copper oxychloride and carbendazim (Jayaraj, 2005). DDT and BHC are highly lipophiclic, accumulate in the different component of the environment and disturb the ecosystem. Keeping in view this problem, Govt. of India banned 12 pesticides in June 1993 and placed DDT under restricted use only in public health programe. During the usage of POP era, residues of these persistent pesticides were detected most frequently in food commodities. However, thereafter the shift in pesticide usage trend has indicated the more use of OP and SP compounds.

The excessive use of pesticides in Himachal Pradesh has also been observed on main cash crops being grown as main and off-season crops. A total of 842 samples of different vegetable crops collected from different parts of the State since 1990 revealed >70% contamination of EBDC (mancozeb, zineb, maneb, antracol etc.) residues followed by 2% MBC (carbendazim) and 1% organochlorines. A decline in pesticide residue contamination has been observed after 2001.

Table1. List of pesticides/pesticides formulations banned in IndiaA. Pesticides Banned for manufacture, import and use

1. Aldrin

2. Benzene Hexachloride

3. Calcium Cyanide

4.

Chlordane

5.

Copper Acetoarsenite

6.

CIbromochloropropane

7.

Endrin

8.

Ethyl Mercury Chloride

9.

Ethyl Parathion

10.

Heptachlor

11.

Menazone

12.

Nitrofen

13.

Paraquat Dimethyl Sulphate

14.

Pentachloro Nitrobenzene

15.

Pentachlorophenol

178

In order to assure the absence or presence of pesticide residues below MRL in a particular commodity, supervised field trials are conducted on that commodity and then post harvest interval or a safe waiting period is suggested. Different waiting periods suggested are tabulated in the table 2 for the safety of consumers.

16. Phenyl Mercury Acetate

17.

Sodium Methane Arsonate

18.

Tetradifon

19.

Toxafen

20.

Aldicarb

21.

Chlorobenzilate

22.

Dieldrine

23.

Maleic Hydrazide

24.

Ethylene Dibromide

25.

TCA (Trichloro acetic acid)

26

Endosulfan (Interim ban by SC)

27

Lindane (To be banned w.e.f. April 2013)

B. Pesticide/Pesticide formulations banned for use but their

manufacture is allowed for export

1.

Nicotin Sulfate

2.

Captafol 80% Powder

C. Pesticide formulations banned for import, manufacture and use

1.

Methomyl 24% L

2.

Methomyl 12.5% L

3.

Phosphamidon 85% SL

4.

Carbofuron 50% SP

D. Pesticide Withdrawn

1. Dalapon

2. Ferbam

3. Formothion

4. Nickel Chloride

(Source: Anonymous, 2008)

179

Table 2. Waiting period for vegetables

Conclusion

Under the present consumer awareness situation, the production of vegetables is under scanner of consumers who are scared of their contamination with pesticide residues. It is the urgent need to convince them with data that all vegetables available in the market do not always carry pesticide load and there is a difference between contamination below MRL and above MRL. The mere presence of a trace amount of a pesticide does not mean that the product is unhealthy. Thus, not eating of vegetable and fruits would pose bigger risk to health than eating low level contaminated food. Food containing residues below MRL do not cause health risk. Following the pre harvest interval, residues go down below legal permissible limit. The use of recommended pesticide with right dose and interval and more importantly observing recommended pre harvest interval is the only way to convince consumers and to ensure our farmer's credibility in export market. Hence establishment of MRL for each pesticide on each vegetable is required. Further, cooking of vegetables followed by washing provide a satisfactory relief from pesticide residues.

180

Pesticide Cauli-

flower Okra Brinjal Cabbage Tomato Pea Knol-khol

Endosulfan

4

3

3

6

-

-

-Monocrotophos

16

12

15

-

15

-

-Fenvalerate

3

2

3

3

3

-

-Carbaryl

10

-

-

5

-

-

-Quinalphos

20

-

-

15

-

-

-Bitertanol

-

-

-

-

-

1

-Mancozeb

-

5

4

27

5

-

22Propineb

-

-

-

-

3

-

-â - cyfluthrin

-

-

-

10

12

5

-Chlorpyriphos

-

-

1

-

-

-

-Malathion

-

-

-

-

1

-

-Dichlorvos

-

-

-

-

1

-

-

References

Anonymous (2008) Central Insecticides Board & Registration Committee, Ministry of Agriculture,NH4, CGO Complex, Faridabad, 121001, http://cibrc.nic.in.

Jayaraj, S. (2002). Prudent management of pests; In: The Hindu Survey of Indian Agriculture 2002. 232pp.

Jayaraj, S. (2005). Use and abuse of chemical pesticides: need for safer pesticides for sustainable integrated pest management. (In): Sustainable Insect Pest Management (ed. Ignaciuthu, S. and Jayaraj, S.), Narosa Publishing House, New Delhi, 2005,253-265p.

Jayaraj, S. and Ignaciuthu, S. (2005) Progress and perspectives of sustainable integrated pest management.(In) Sustainable Insect Pest Management (ed. Ignaciuthu, S. and Jayaraj, S.), Narosa Publishing House, New Delhi, 2005,1-18p.

181

Management of Pollinators of Vegetable Crops under Changing Climatic Scenario

R K Thakur and Jatin Soni

Department of Entomology and ApicultureDr YS Parmar University of Horticulture and Forestry, Nauni-173230, Solan

Introduction

Continuous declining weather conditions and changes in climate due to the escalating temperature, erratic rainfall, more demand for water and enhanced incidence of diseases are all set to affect the production trend of various vegetable crops. The increasing temperature day-by-day due to global warming is 0.76°C since 1850. The rate of warming in the last 50 years is double than that for the last century. As many as 11 of the past 12 years were the warmest since1980. The increase in temperature is of 1.8-4°C by the next century (Rowntree, 1990). The threshold value of temperature rise is 2°C for devastating, dangerous and irreversible consequences of warming to manifest the world over. Global warming is occurring along with shifting pattern of rainfall and increasing incidence of extreme floods, droughts and frosting. The rapid industrialisation, intensive agriculture, indiscriminate use of chemicals and fertilisers, deforestation and increasing use of fossil fuels during the past 150 years are major factors for the climate change. The continued effect of these activities results in increasing emission of CO and other greenhouse gases, leading 2

to global warming as a greenhouse effect (Porter et al., 1991;).

There are considerable uncertainties about agronomic implications of vegetable crops. Predicting impact of climate change on vegetable crops accurately on regional scale is a big problem. Current estimates of changes in climate indicate an increase in

0 0global mean annual temperatures of 1 C by 2025, and 3 C by the end of the next century (IPCC, 1999a; b). The date at which an equivalent doubling of CO will be 2

attained is estimated to between 2025 and 2070¸depending on the level of emission of greenhouse gasses (IPCC, 1990a; b).

Pollination and status of pollinators

Pollination is a crucial stage in the reproduction of most flowering plants, and pollinators are essential for transferring genes within and among populations of wild plant species (Kearns et al. 1998). Although the scientific literature has mainly focused on pollination limitations in wild plants, in recent years there has been an increasing recognition of the importance of pollination in food production. Klein et

al. (2007) found that fruit, vegetable or seed production from 87 of the world's leading food crops depend upon animal pollination, representing 35 percent of global food production. Roubik (1995) provided a detailed list for 1330 plant species, showing that for approximately 70 percent of crops, at least one variety is improved by pollination. Sutherst, 1991 also emphasized that flower-visiting insects provide an important ecosystem function to global crop production through their pollination services.

Pollinators are vital to agriculture. Most fruit, vegetable, and seed crops and some crops that provide fiber, drugs and fuel are pollinated by animals. Pollination by animals also is essential for maintaining the structure and function of a wide range of natural communities. In view of that economic and ecological importance, the putative causes of decline of the pollinators and potential consequences of those declines are:

Temperature increases associated with climatic changes could result in:

vExtension of geographical range of pollinators

vIncreased over-wintering and rapid population growth

vImpact on pollinator diversity and extinction of species

Climatic change will result in increased problems with pollinators. These changes will have major implications for crop protection and food security, particularly in the developing countries, where the need to increase and sustain food production is most urgent. Improved techniques for managing pollinators require weather and insect data from thoroughly maintained monitoring as well as climate information and forecast to determine their suitability. Climatic change, including global warming and increased variability require improved analyses that can be used to assess the risk of the existing and the newly developed pollinators management strategies and techniques, and to define the impact of these techniques on environment, productivity and profitability (Lee et al.,2009 a; b)

Insect pollinators are valuable and limited resources (Delaplane and Mayer 2000). Currently, farmers manage only 11 of the 20 000 to 30 000 bee species worldwide (Parker et al. 1987), with the European honey bee (Apis mellifera) being by far the most important species. Depending on only a few pollinator species belonging to the Apis genus has been shown to be risky. Apis-specific parasites and pathogens have lead to massive declines in honey bee numbers. Biotic stress accompanied with climate change may cause further population declines and lead farmers and researchers to look for alternative pollinators. Well-known pollinators to replace honey bees might include the alfalfa leaf-cutter bee (Megachile rotundata) and alkali bee (Nomia melanderi) in alfalfa pollination (Cane 2002), mason bees

183

(Osmia spp.) for pollination of orchards (Bosch and Kemp 2002; Maccagnani et al. 2003) and bumble bees (Bombus spp.) for pollination of crops requiring buzz pollination (Velthuis and van Doorn 2006). Stingless bees are particularly important pollinators, visiting approximately 90 crop species (Heard 1999). Some habits of stingless bees resemble those of honey bees, including their preference for a wide range of crop species, making them attractive for commercial management.

Pollinators' sensitivity to elevated temperatures

Bees are the most important pollinator worldwide (Kearns et al. 1998) and like other insects, they are ectothermic, requiring elevated body temperatures for flying. The thermal properties of their environments determine the extent of their activity (Willmer and Stone 2004). The high surface-to-volume ratio of small bees leads to rapid absorption of heat at high ambient temperatures and rapid cooling at low ambient temperatures. All bees above a body mass of between 35 and 50 mg are capable of endothermic heating, i.e. internal heat generation (Stone and Willmer 1989; Stone 1993; Bishop and Armbruster 1999). Examples of bee pollinators with a body weight above 35 mg are found in the genera Apis, Bombus, Xylocopa and Megachile. Examples of small bee pollinators are found in the family Halictidae, including the genus Lasioglossum. All of these groups are important in vegetable crop pollination. In addition to endothermy, many bees are also able to control the temperatures in their flight muscles before, during and after flight by physiological and behavioural means (Willmer and Stone 1997). Examples of behavioural strategies for thermal regulation include long periods of basking in the sun to warm up and shade seeking or nest returning to cool down (Willmer and Stone 2004). With respect to the potential effects of future global warming, pollinator behavioural responses to avoid extreme temperatures have the potential to significantly reduce pollination services (Corbet et al. 1993).

Conservation and management of pollinators

Pollinators are an element of crop associated biodiversity, and provide an essential ecosystem service to both natural and agricultural ecosystems. In the case of agricultural ecosystems, pollinators and pollination can be managed ("planned" crop associated biodiversity) to maximize or improve crop quality and yield. The negative impact of the loss of pollinators is strongly felt in agricultural biodiversity. The role of pollinators is, among other things, to ensure reproduction, fruit set development and dispersal in plants, both in agro ecosystems and natural ecosystems. The principle factor which determines the effectiveness of such pollinators for a particular vegetable crop or plant species depends upon the bee abundance, bee flight period, bee flight hours per day and the number of flowers visited per day. The factors which contribute to bee survival in nature and their

184

propagation depends upon the availability of natural or manmade nesting devices of preferred dimensions, abundance of natural parasitic, or predators, incidence of disease or pesticide poisoning, and the natural brood mortality during active or the dormant season. Most important is the synchronization of the bee flight period with the major blooming period of the crop. This is achieved through appropriate provisions of nesting devices and regulating development of adults so that there is synchrony in adults formation with crop blooming. Following are the characteristic features of such bee management programmes for crop pollination.

i) Provision of appropriate nesting devices of brood cell formation.

(ii) Collection and safe storage of brood nest of cells at low temperature.

iii) Checking/controlled emergence of parasites or removal diseased cells.

iv) Incubation of cells at appropriate temperature to regulate formation

Implication of climate change in vegetable production

The climate change will have many impacts on horticulture and a few examples are given below.

i. A rise in a temperature of above 1ºC will have shifted a major area of potential suitable zones.

ii. Production timing will change. Because of rise in temperature, crops will develop more rapidly and mature earlier.

iii. While temperature rises, photoperiods may not show much variation. Onions, a photosensitive crop, will mature faster leading to small bulb size.

iv. The winter regime and chilling duration will reduce in temperate regions affecting the temperate crops.

v. The faster maturity and higher temperature induced ripening will make the produce a less storage period in trees/ plants. They will overripe.

vi. Pollination will be affected adversely because of higher temperature. Floral abortions will occur.

vii. Soil temperature will increase much earlier in spring hence the planting time also will advance. This can be catastrophic if late frosts occur.

viii.The requirement of annual irrigation will increase, not because of higher evaporation, because the trees develop more fasters during the 12 month period.

ix. Higher temperatures will reduce tuber initiation process in potato, reduced quality in tomatoes and poor pollination in many crops. In case of crucifers, it may lead to bolting; anthocyanin production may be affected in capsicum.

185

Adapting to changing climate

Crops produce optimally with a suite of pollinators possibly including, but not limited to managed honeybees. A diverse assemblage of pollinators, with different traits and responses to ambient conditions, is one of the best ways of minimizing risks due to climatic change. The "insurance" provided by a diversity of pollinators ensures that there are effective pollinators not just for current conditions, but for future conditions as well. Resilience can be built in agro-ecosystems through biodiversity. Pollination management practices can also be undertaken to respond to climate change. Examples of how farming communities may best adapt to climate change impacts on pollinators include giving consideration to the seasonal availability of resources needed by pollinators, and ensuring connectivity of natural habitats in farming areas (allowing easier pollinator dispersal for range shifts in response of climatic change.

Table 1. Important non - Apis bee pollinators of some vegetable crops in India

Sustainable farming helps endangered insect pollinators using sustainable farming

The sustainable farming helps endangered insect pollinators using sustainable farming techniques, which balance environmentally and economically agriculture method has show that more vegetable plant pollinators are present under

Crop/plant Family Bee species Pea Leguminosae X. fenestrata X. pubescens Megachile lanata

Braunsapis spp X. fenestrata X. pubescens M.cephalotes M.flavipesB.albopleuralis Bombus asiaticu Lasioglossum spp

Sweet potato

Convolvulaceae

X. fenestrata B.albopleurali Bombus asiaticus s

Egg plant

Solanaceae

B. asiaticus

X. fenestrata Ameigilla delicata A.subcosrulea Nomia caliphora Pithitis spp

Onion Liliaceae

Nomioides spp

Lasioglossum spp Nomioides spp X. fenestrata

Field mustard

Cruciferae

Nomioides Megachilids Andrenids Halictids

Andrena ilerda A.leaena

Cabbage & cauliflower

Cruciferae

Andrena ilerda Lassioglossum spp Pithitis smaragdula

Raddish Cruciferae

Anthophora spp Nomia spp Lassioglossum sppColletes spp

Pumpkin & squashes

Cucurbitaceae

X. fenestrata X. pubescens Halictus spp Nomioides spp

Cucumbers

Cucurbitaceae

Nomia spp P. smaragdula Nomioides variegata Halictids

Lasioglossum sppCorriander Umbelliferae Nomioides spp Halictidae X. fenestrateCarrot Umbelliferae Lasioglossum spp Sphecoides Hyleaus Nomioides

Braunsapis Pithitis smaragdula

186

these conditions. Their ecological farming programmes combine the benefits of the modern agricultural techniques with organic and sustainable practices including providing healthy environment for native insect pollination. These sustainable farming practices may show the decline in beneficial insect population and improve vegetable crop production.

Conclusion

The phenology, geographic distribution and local abundance of plants and pollinators appear to be affected by recent climate change. Nevertheless, the current knowledge of the potential ecological consequences of increasing temperatures is limited and often must be deduced from indirect evidence or basic ecological knowledge of pollination interactions or studies of the mutualistic partners separately. Timing of both plant flowering and pollinator activity appears to be strongly affected by temperature, and their response appears to be linear within the limits of temperature fluctuation observed during recent decades. Thus, plant and pollinator responses to climate warming may act in concert, although there may be considerable variation in the thermal sensitivity across species.

References:

Bishop, J.A. & Armbruster, W.S. 1999. Thermoregulatory abilities of Alaskan bees: effects of size, phylogeny and ecology. Funct Ecol, 13: 711-724.

Bosch, J. & Kemp, W.P. 2002. Developing and establishing bee species as crop pollinators: the example of Osmia spp. (Hymenoptera : Megachilidae) and fruit trees. Bull Entomol Res, 92: 3-16.

Cane, J.H. 2002. Pollinating bees (Hymenoptera : Apiformes) of US alfalfa compared for rates of pod and seed set. J Econ Entomol, 95: 22-27.

Corbet, S.A. Fussell M., Ake R., Fraser A., Gunson C., Savage A. & Smith K. 1993.Temperature and the pollinating activity of social bees. Ecol Entomol, 18: 17-30.

Delaplane, K.S. & Mayer, D.F. 2000. Crop pollination by bees. New York, CABI.

Heard, T.A. 1999. The role of stingless bees in crop pollination. Annu Rev Entomol, 44: 183-206.

IPCC. 1990a. Climate change: The IPCC Scientific Assessment. Intergovernmental Panel on Climate Change. Geneva and Nairobi, Kenya: World Meteorological Organization and UN Environment Program, 365p.

Kearns, C.A., Inouye, D.W. & Waser, N.M. 1998. Endangered mutualisms: the conservation of plant pollinator interactions. Annu Rev Ecol Syst, 29: 83-112.

Klein, A.M., Vaissiere, B. E., Cane, J. H., Steffan-Dewenter, I., Cunningham, S. A., Kremen, C. & Tscharntke, T. 2007. Importance of pollinators in changing

187

landscapes for world crops. Proc R Soc Lond [Biol], 274: 303-313.

Lee, J.H., Stahl, M., Sawlis, S. and Suzuki, S. 2009b. A potential risk assessment of a dengue outbreak in North Central Texas, USA( Part 2 of 2): development of a practical prevention strategy. Journal of Environmental Health. 71:36-39.

Lee, J.H., Stahl, M., Sawlis, S.,Suzuki, S. And Lee, J.H. 2009a. A potential risk assessment of a dengue outbreak in North Central Texas, USA( Part 1 of 2): abundance and temporal variation of dengue vectors. Journal of Environmental Health. 71:24-29

Maccagnani, B., Ladurner, E., Santi, F. & Burgio, G. 2003. Osmia cornuta (Hymenoptera, Megachilidae) as a pollinator of pear (Pyrus communis): fruit- and seed-set. Apidologie, 34: 207-216.

Parker, F.D., Batra, S.W.T. & Tepedino, V.J. 1987. New pollinators for our crops. Agricult Zool Rev, 2: 279-304.

Porter, J.H.., Parry, M. L. and Carter, T.R.1991. The potential effects of climatic change on agricultural insect pests. Agricultural and Forest Meteorology.57: 221-240

Roubik, D.W. (ed.) 1995. Pollination of cultivated plants in the tropics. Rome, FAO.

Rowntree, P.R. 1990. Estimate of future climatic change over Britain.Weather.45:79-88

Stone, G.N. & Willmer, P.G. 1989. Endothermy and temperature regulation in bees – a critique of grab and stab measurement of body-temperature. J Exp Biol, 143: 211-223.

Stone, G.N. 1993. Endothermy in the solitary bee anthophora-plumipes – independent measures of thermoregulatory ability, costs of warm-up and the role of body size. J Exp Biol, 174: 299-320.

Sutherst, R.W. 1991. Pest risk analysis and the green house effect. Review of agricultural Entomology.79:1177-1187

Velthuis, H.H.W. & van Doorn, A. 2006. A century of advances in bumblebee domestication and the economic and environmental aspects of its commercialization for pollination. Apidologie 37: 421-451.

Willmer, P. & Stone, G. 1997. Temperature and water relations in desert bees. J Thermal Biol, 22: 453-465.

Willmer, P.G. & Stone, G.N. 2004. Behavioral, ecological, and physiological determinants of the activity patterns of bees. In: Advances in the Study of Behavior Vol. 34. San Diego, CA, Elsevier Academic Press Inc. pp. 347-466.

188

Vegetable Intercropping in Sugarcane for Greater Productivity and Profitability

1 2RK Sharma and Samar Singh

1 2 Directorate of Wheat Research and CCSHAU Regional Station, Karnal, Haryana

Sugarcane is a wide row spacing autumn, spring and late spring season planted important sub-tropical commercial crop of India. The autumn planted sugarcane gives 15-20% and 25-30% higher cane yield compared to spring and late spring planting, respectively (Verma et al.1981; Singh et al. 1997). Autumn planting is not popular among farmers due to late harvesting of kharif crops (Paddy, sorghum etc.), myth of losing Rabi crop and limited transfer of technology.

The growth of sugarcane during initial stages (90-100 days) is slow providing sufficient uncovered area for intercrops to efficiently utilize space, nutrients, water and solar energy thereby increasing land use efficiency, reducing the production cost and making the system profitable and sustainable. Recently, the emphasis is not only on yield but also on maintaining or rather improving the natural resource base and maximizing the profit by efficient utilization of various inputs. Intercropping sugarcane with short duration crops is advantageous and provides additional income (Ayyer 1963). Several workers (Rathi and Singh 1979 and Rana et al. 1999) observed that potato, peas, toria, mustard, wheat, winter maize, mentha and sunflower can be profitably intercropped with autumn sugarcane.

The intercropping is the necessity owing to increasing demand for food, fibre and fodder. Wheat is an important crop for national food security and farmers are also not ready to leave it for autumn planted sugarcane. Hence, intercropping wheat with autumn planted sugarcane is a suitable option for enhancing farmers' income as well as area under autumn planted sugarcane in sub-tropical India. Cane yield is low with farmer's practice of intercropping on flat check basins and planting sugarcane after Rabi crops. For higher sugarcane yield, bed planting provides the option for mechanized sowing of intercrops followed by manual planting of sugarcane in the furrows besides saving of water and other inputs. Moreover, intercropping potato, pea, lentil, green gram and black gram helps maintain soil fertility and natural resources whereas intercropping fenugreek and coriander also repel insects.

Advantages of Intercropping

• Augment sugarcane farmers' income with little additional cost.

• Offers opportunity to engage nature's principle of diversity.

• Better utilization of soil moisture, nutrients and solar radiation than sole cropping

• Additional employment for the agricultural labourers and farm families.

• Meeting the farmer's need for other crops like cereals, oilseeds, pulses and vegetable.

• Various leguminous intercrops fix atmospheric nitrogen.

• Reduced total water requirement of both crops and enhanced water use efficiency.

• Substantial energy saving (60 litres diesel/ha) due to concurrent planting.

• Better weed management especially in the inter spaces.

• Enhanced biodiversity, biological control of insect pests and long term sustainability.

• Higher cane yield due to autumn planting and greater sugar recovery.

• Creating additional acreage under cereals, oilseeds, pulses and vegetables.

• Crop residue recycling vis-à-vis maintenance of the soil health.

• Mid-season income generation from intercrops.

Small farmers show a preference for intercropping because the system provides a greater stability of production by minimizing climatic risks, and it allows for a more equal distribution of labour throughout the season, thus encouraging the farmer to stay on the land. Intercropping can provide a higher productivity per unit area of land, and it tends to provide a greater diversity of food and income sources.

About the technology

The most important requirement for the successful intercropping system is the laser land levelling and a multiple crop bed planter. Bed planter need to be adjusted in such a way that it makes two beds at a time with row to row distance of 90 cm i.e. 90 cm distance form centre of the furrow to the centre of the adjoining furrow with bed top of about 55 cm. Intercrops are sown/planted with bed planter on the beds with the recommended crop geometry. The recommended doses of fertilizers for intercrops except P are applied in the soil at the last ploughing before making beds, whereas, P is drilled using bed planter while seeding the crops. The recommended doses of fertilizers for sugarcane are applied in the furrows then put the cane sets and cover them with one to two inches of soil. Apply light irrigation in furrows two to three days after planting of sugarcane to maintain soil moisture. If required apply one more light irrigation after 10-12 days for proper germination and crop establishment.

190

Why intercropping using bed planters?

• Water saving (30-40%)

• More yield of intercrops

• Reduction in seed rate (22-25%)

• Facilitate light irrigations to sugarcane during intercrop's maturing period

• Proper aeration and sunlight to sugar cane crop

• Efficient utilization of nutrients

• Reduced adverse effects of heavy rains

Aspects of successful intercropping

Five distinct aspects to successful intercropping are proper planning, timely planting of each crop, adequate fertilization at the optimal times, effective weed & pest control and efficient harvesting. Planning covers selection of crop species and appropriate cultivars, water availability, plant populations and spacing, labour requirements throughout the season, tillage requirements, and predicted profitability of the intercrop. These and other parameters, if any, need to be considered and evaluated before spending money on inputs.

Selection of compatible crops and genotypes

• Short duration, erect and dwarf intercrops/genotypes

• Should have no allelopathic effect

• Easy to manage having assured market

• Should not attract more pest and diseases

• Input requirement not too different than sugarcane

• Should have uniform maturity

Planting/Sowing

• Sugarcane planting immediately following intercrop sowing/planting

• North-South row arrangement to avoid shading effects

• If pulse/leguminous intercrop, inoculate with Rhizobium

• Decide seed rate based on net area under intercrop

191

Planting density and geometry

Proper plant density and geometry of intercrops is important to realize the full yield advantage accruing from the intercropping system.

Fertilizer dose and management

Fertilizer management is a major key to harvest full yield potential of the intercropping system since the intercrops are of different nature of growth and nutrients need. The nutritional requirement of both the crops should be fully met separately. For intercrop, the fertiliser should be applied based on the net area under intercrop for optimum use efficiency and greater profitability followed by full dose to the main sugarcane crop. The time of fertilizer application is very important in deciding fertilizer use efficiency and yield of the cropping system. The dose and time of fertilizer application to intercrop may be similar to its sole cropping. To sugarcane, one third nitrogen, full doses of phosphorus, potash and zinc sulphate should be applied at the time of planting and the remaining doses of N application to sugarcane should be made after the harvesting of intercrop.

Irrigation

Irrigation in the intercropping system should be applied as per the requirement of intercrop until its harvesting and as per the sugarcane requirement after intercrop harvesting.

Pest management

Coriander and garlic are the most effective intercrops to control the pest (top borer) infestation in sugarcane due to their pest repellent properties (Verma et al.

st nd1981). The 1 and 2 brood of top borer was also drastically reduced when sugarcane was intercropped with wheat probably due to physical barrier. Infestation of pink borer was much less when sugarcane was intercropped with potato. Intercropping sugarcane with mustard or wheat is effective in arresting the dispersal of smut spores with in the field. Sugarcane wilt was reduced when coriander, rai, wheat and potato were intercropped with sugarcane.

Weed management

Weed management in intercropping system is a major problem as almost all the recommended herbicide for sugarcane are harmful to leguminous intercrops. The herbicide which is selective to both the crops needs to be used. However, pendimethalin @ 1000 g/ha followed by one hoeing at 45 days after planting/sowing has been found effective in controlling weeds in wheat, chickpea, garlic, onion, pea, potato, cabbage, cauliflower, knol-khol, lentil, coriander, green gram, black gram, cucumber, long melon, round melon, lady finger and muskmelon.

192

Economics of intercropping

Economics is an important factor to favour any intercropping system which depends on the various factors such as reduction in cane yield, intercrop yield and its market price, etc. Goni and Paul (2005) reported that intercropping one or more crops with sugarcane cultivation could profitable by earning higher net profit and keep abreast besides crop competition. Yadav and Verma (1984) have reported that intercropping of sugarcane with other crops was found profitable particularly in the sub tropical region of India. Imam et al. (1982) reported that sugarcane + Potato + Amaranth was more profitable followed by Sugarcane + Onion than the sole sugarcane crop. Hossain et al. (1995) conducted that soybean and some pulses and oil seed crops as intercropped with paired row transplanted sugarcane gave

-1additional economic return and added about 3.5 to 4.5 t ha biomass to soil which is useful for soil organic matter. Ali et al. (1989) found that short duration winter crops like potato, garlic, onion, tomato, cabbage, chilli and mustard are grown in vacant space between two rows of sugarcane before canopy development to get an additional crop with minimum investment without affecting of main crop sugarcane and also found that intercropping potato with sugarcane increased cane yield compared of different row adjustment. Singh and Singh (1973) also found increased cane yield by 64.3% from intercropping potato with sugarcane. Kabir (1988) also observed that potato, mustard and gram are most compatible intercrops with sugarcane. Islam et al. 2009 reported that intercropping of potato, chilli, garlic and other suitable crops is superior to only cane cultivation and the practice helps to earn additional income. However some points which may be kept in mind to realize higher economic returns from intercropping are;

a) Management of intercropping system in a way that there is no cane yield reduction when compared with sole sugarcane crop.

b) Intercrop should be easily manageable, high value and have assured market.

c) The labour and input requirement of the intercrop should not be very high so that the variable cost of cultivation is relatively low leading to higher net profits.

Reason for low adoption of intercropping

• Additional labour is required for raising an intercrop in sugarcane and its availability is becoming scarce and costly. For the success of intercropping timely operation is important which become difficult due to labour scarcity.

• Intercrop management is a somewhat inconvenient practice.

• No serious efforts are made to popularize intercropping system.

• Narrow planting period

• Harvesting during cooler months

193

Suggestions for improved productivity

• Well levelled field

• Perfection of bed-planter

• 1-2 light irrigation after planting cane

• Gap filling of sugar cane just after harvesting of intercrops

• Apply irrigation and remaining fertilizer to sugarcane just after harvesting of intercrops

Conclusion: Intercropping in sugarcane is feasible. For greater productivity and profitability, choice of appropriate intercrops and their varieties coupled with suitable crop management practices is a must.

References:

Ali M, AHMD Hossain, SA Imam and M Shaheen. 1989. Row adjustment of sugarcane on the yield of intercropped cane and potato. Bangladesh J. Sugarcane. 11: 78-82.

Ayyer AKYN. 1963. Principles of crop husbanding in India, Banglore Press, Edition th4 pp. 250-257.

Goni MO and SK Paul. 2005. Sustainability of sugarcane cultivation through paired row planting system with wide spacing and double intercropping. Bangladesh J. Sugarcane. 24-27: 26-32.

Hossain AHMD, MK Rahman, ML Kabir, MA Matin and MJ Alam.1995. Performance of soybean and some other crops as intercrops with paired row transplanted sugarcane. Bangladesh J. Sugarcane, 17: 119-122.

Imam SA, A Ali and MA Razzaque. 1982. Performance of intercropping with sugarcane under several crop combinations. Bangladesh J. Sugarcane, 4: 32-41.

Islam MA, MNA Miah, MA Rahman, MA Kader and KMR Karim. 2009. Performance of Sugarcane with Different Planting Methods and Intercrops in Old Himalayan Piedmont Plain Soils. Int. J. Sustain. Crop Prod. 4(1):55-57

Kabir MH. 1988. Economics of intercropping with sugarcane in selected areas of North Bengal Sugar Mills Zone. Bangladesh J. Sugarcane, 10: 81-86

Rana NS, Saini, SK and Singh, TP. 1999. Production potential and economics of sugarcane based cropping systems. Indian journal of sugarcane technology 14 (2): 85-88.

194

Rathi KS and RA Singh. 1979. Companion cropping with autumn planted sugarcane- a critical review: 1. intercropping of mustard with autumn planted sugarcane. India sugar crops journal. 6 (4): 76-82.

Singh PP and K Singh. 1973. Studies on the intercropping of sugarcane multiple cropping. Indian Soc. Agron. New Delhi, India

Singh, SN, JP Shukla, ML Agarwal and GP Singh. 1997. Productivity of sugarcane and sugar as influenced by season of planting and dates of Harvesting in U.P. Indian sugar.47 (1): 35-42.

Verma, RS, MP Motiwale, RS Chauhan, and RK Tewari. 1981. Studies on spices and tobacco with autumn sugarcane. Indian Sugar. 31 (7): 451-456.

Yadav RL and RP Verma. 1984. Transfer of the intercropping technique to sugarcane growers. Indian Sugar Crops J., 10: 1-2.

195

Role of Crop Modelling in Mitigating Effects of Climate Change on Crop Production

R S Spehia

Department of Soil Science and Water ManagementDr YS Parmar University of Horticulture & Forestry, Nauni, Solan-173 230

Despite technological advances, such as improved varieties, genetically modified organisms, and irrigation systems, weather is still a key factor in agricultural productivity, as well as soil properties and natural communities. The effect of climate on agriculture is related to variabilities in local climates rather than in global climate patterns. The Earth's average surface temperature has increased by 0.83°C since 1880. On the other hand, agricultural trade has grown in recent years, and now provides significant amounts of food, on a national level to major importing countries, as well as comfortable income to exporting ones. Consequently, agronomists consider any assessment has to be done individually considering each local area. A study published in Science suggests that, due to climate change, "southern Africa could lose more than 30% of its main crop, maize, by 2030. In South Asia, losses of many regional staples, such as rice, millet and maize could top 10

(1)(2) %".

Specifically, it is very early to imply the effect of climate change on vegetable crops and more studies are required to be undertaken before any conclusion can be drawn. Therefore, the present paper deals with effect of climate change on agricultural crops in general. The Intergovernmental Panel on Climate Change (IPCC) has produced several reports that have assessed the scientific literature on climate change. The IPCC Third Assessment Report, published in 2001, concluded that the poorest countries would be hardest hit, with reductions in crop yields in most tropical and sub-tropical regions due to decreased water availability, and new or changed insect pest incidence. In Africa and Latin America many rainfed crops are near their maximum temperature tolerance, so that yields are likely to fall sharply for even small climate changes; falls in agricultural productivity of up to 30% over the 21st century are projected. Marine life and the fishing industry will also be severely affected in some places. Climate change induced by increasing greenhouse gases is likely to affect crops differently from region to region. For example, average crop yield is expected to drop down to 50% in Pakistan according to the UKMO scenario whereas corn production in Europe is expected to grow up to 25% in optimum hydrologic conditions. More favourable effects on yield tend to depend to a large extent on realization of the potentially beneficial effects of carbon dioxide on crop

growth and increase of efficiency in water use. Decrease in potential yields is likely to be caused by shortening of the growing period, decrease in water availability and poor vernalization. In the long run, the climatic change could affect agriculture in several ways.

Most agronomists believe that agricultural production will be mostly affected by the severity and pace of climate change, not so much by gradual trends in climate. If change is gradual, there may be enough time for biota adjustment. Rapid climate change, however, could harm agriculture in many countries, especially those that are already suffering from rather poor soil and climate conditions, because there is less time for optimum natural selection and adaption.

Observed impacts

So far, the effects of regional climate change on agriculture have been [3]

relatively limited. Changes in crop phenology provide important evidence of the [4]

response to recent regional climate change. Phenology is the study of natural phenomena that recur periodically, and how these phenomena relate to climate and

[5]seasonal changes. A significant advance in phenology has been observed for [3]

agriculture and forestry in large parts of the Northern Hemisphere.

Crop development models

Models for climate behavior are frequently inconclusive. In order to further study effects of global warming on agriculture, other types of models, such as crop development models, yield prediction, quantities of water or fertilizer consumed, can be used. Such models condense the knowledge accumulated of the climate, soil, and effects observed of the results of various agricultural practices. They thus could make it possible to test strategies of adaptation to modifications of the environment. Because these models are necessarily simplifying natural conditions (often based on the assumption that weeds, disease and insect pests are controlled), it is not clear whether the results they give will have an in-field reality. However, some results are partly validated with an increasing number of experimental results.

Types of models

Depending upon the purpose for which it is designed the models are classified into different groups or types. Of them a few are :

a. Statistical models: These models express the relationship between yield or yield components and weather parameters. In these models relationships are measured in a system using statistical techniques Example: Step down regressions, correlation, etc.

197

b. Mechanistic models: These models explain not only the relationship between weather parameters and yield, but also the mechanism of these models (explains the relationship of influencing dependent variables). These models are based on physical selection.

c. Deterministic models: These models estimate the exact value of the yield or dependent variable. These models also have defined coefficients.

d. Stochastic models: A probability element is attached to each output. For each set of inputs different outputs are given along with probabilities. These models define yield or state of dependent variable at a given rate.

e. Dynamic models: Time is included as a variable. Both dependent and independent variables are having values which remain constant over a given period of time.

f. Static: Time is not included as a variable. Dependent and independent variables having values remain constant over a given period of time.

g. Simulation models: Computer models, in general, are a mathematical representation of a real world system. One of the main goals of crop simulation models is to estimate agricultural production as a function of weather and soil conditions as well as crop management. These models use one or more sets of differential equations, and calculate both rate and state variables over time, normally from planting until harvest maturity or final harvest.

h. Descriptive model: A descriptive model defines the behaviour of a system in a simple manner. The model reflects little or none of the mechanisms that are the causes of phenomena. But, consists of one or more mathematical equations. An example of such an equation is the one derived from successively measured weights of a crop. The equation is helpful to determine quickly the weight of the crop where no observation was made.

i. Explanatory model: This consists of quantitative description of the mechanisms and processes that cause the behaviour of the system. To create this model, a system is analyzed and its processes and mechanisms are quantified separately. The model is built by integrating these descriptions for the entire system. It contains descriptions of distinct processes such as leaf area expansion, tiller production, etc.

Future Projections of climate change in different Continents

As part of the IPCC's Fourth Assessment Report, Schneider et al. (2007) [6]projected the potential future effects of climate change on agriculture. With low to

medium confidence, they concluded that for about a 1 to 3 °C global mean

198

temperature increase (by 2100, relative to the 1990–2000 average level) there would be productivity decreases for some cereals in low latitudes, and productivity increases in high latitudes. In the IPCC Fourth Assessment Report, "low confidence" means that a particular finding has about a 2 out of 10 chance of being correct, based on expert judgment. "Medium confidence" has about a 5 out of 10 chance of being

[7]correct. Over the same time period, with medium confidence, global production

[6]potential was projected to:

Asia: With medium confidence, IPCC (2007) projected that by the mid-21st century, in East and Southeast Asia, crop yields could increase up to 20%, while in Central and South Asia, yields could decrease by up to 30%. Taken together, the risk of hunger was projected to remain very high in several developing countries.

Australia and New Zealand: Hennessy et al. (2007) assessed the literature for this [8]

region. They concluded that without further adaptation to climate change, projected impacts would likely be substantial: By 2030, production from agriculture and forestry was projected to decline over much of southern and eastern Australia, and over parts of eastern New Zealand.

Europe: With high confidence, IPCC (2007) projected that in Southern Europe, climate change would reduce crop productivity. In Central and Eastern Europe, forest productivity was expected to decline. In Northern Europe, the initial effect of climate change was projected to increase crop yields.

Latin America: With high confidence, IPCC (2007) projected that in drier areas of Latin America, productivity of some important crops would decrease and livestock productivity decline, with adverse consequences for food security. In temperate zones, soybean yields were projected to increase.

Future Projections of climate change on different Variables

Temperature potential effect on growing period

Duration of crop growth cycles are above all, related to temperature. An increase in temperature will speed up development. In the case of an annual crop, the duration between sowing and harvesting will shorten (for example, the duration in order to harvest corn could shorten between one and four weeks). The shortening of such a cycle could have an adverse effect on productivity because senescence would occur sooner.

Effect of elevated carbon dioxide on crops

Carbon dioxide is essential to plant growth. Rising CO concentration in the 2

atmosphere can have both positive and negative consequences. Increased CO is 2

199

expected to have positive physiological effects by increasing the rate of photosynthesis. Currently, the amount of carbon dioxide in the atmosphere is 380 parts per million. In comparison, the amount of oxygen is 210,000 ppm. This means that often plants may be starved of carbon dioxide, due to the enzyme that fixes CO , 2

rubisco also fixes oxygen in the process of photorespiration. The effects of an increase in carbon dioxide would be higher on C3 crops (such as wheat) than on C4 crops (such as maize), because the former is more susceptible to carbon dioxide shortage. Studies have shown that increased CO leads to fewer stomata developing 2

[10] [11]on plants which leads to reduced water usage. Under optimum conditions of temperature and humidity, the yield increase could reach 36%, if the levels of carbon dioxide are doubled.

Effect on quality

According to the IPCC's TAR, "The importance of climate change impacts on grain and forage quality emerges from new research. Studies using FACE have shown that increases in CO lead to decreased concentrations of micronutrients in 2

[12]crop plants. This may have knock-on effects on other parts of ecosystems as [14]

herbivores will need to eat more food to gain the same amount of protein. . Studies have shown that higher CO levels lead to reduced plant uptake of nitrogen (and a 2

smaller number showing the same for trace elements such as zinc) resulting in crops [15][16]with lower nutritional value. This would primarily impact on populations in

poorer countries less able to compensate by eating more food, more varied diets, or possibly taking supplements.

Erosion and fertility

The warmer atmospheric temperatures observed over the past decades are expected to lead to a more vigorous hydrological cycle, including more extreme rainfall events. Erosion and soil degradation is more likely to occur. Soil fertility would also be affected by global warming. However, because the ratio of carbon to nitrogen is a constant, a doubling of carbon is likely to imply a higher storage of nitrogen in soils as nitrates, thus providing higher fertilizing elements for plants, providing better yields. The average needs for nitrogen could decrease, and give the opportunity of changing often costly fertilization strategies.

Potential effects of global climate change on pests, diseases and weeds

A very important point to consider is that weeds would undergo the same acceleration of cycle as cultivated crops, and would also benefit from carbonaceous fertilization. Since most weeds are C3 plants, they are likely to compete even more than now against C4 crops such as corn. However, on the other hand, some results make it possible to think that weed killers could gain in effectiveness with the

200

temperature increase. Global warming would cause an increase in rainfall in some areas, which would lead to an increase of atmospheric humidity and the duration of the wet seasons. Combined with higher temperatures, these could favor the development of fungal diseases. Similarly, because of higher temperatures and humidity, there could be an increased pressure from insects and disease vectors.

Micro Irrigation

Pressurized irrigation methods, such as sprinkler, drip and micro sprinkler offer possibilities of achieving higher efficiencies of water use through controlled water application. In pressurized irrigation methods water is applied more frequently which in turn reduces the moisture stress to the plants and thus enhances the crop growth. In drip irrigation, water is applied at a very low rate, almost matching the evapotranspiration requirement, resulting into significant water saving. The use of micro irrigation is rapidly increasing around the world, and it is expected to be a viable irrigation method for agricultural production in the foreseeable future. With increasing demands on limited water resources and the need to minimize adverse environmental consequences of irrigation, drip irrigation technology will undoubtedly play an even more important role in the future. It provides many unique agronomic, water and energy conservation benefits that address many of the challenges facing irrigated agriculture, now and in the future.

References

"Climate 'could devastate crops". BBC News. 31 January 2008.

Lobell DB, Burke MB, Tebaldi C, Mastrandrea MD, Falcon WP, Naylor RL (2008). "Prioritizing climate change adaptation needs for food security in 2030". Science 319(5863): 607–10.

Rosenzweig, C (2007). "Executive summary". In ML Parry, et al, (eds.). Chapter 1: Assessment of Observed Changes and Responses in Natural and Managed Systems. Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press (CUP).

Rosenzweig, C (2007). "1.3.6.1 Crops and livestock". In ML Parry, et al, (eds.).Chapter 1: Assessment of Observed Changes and Responses in Natural and Managed Systems. Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press (CUP):

201

ML Parry, et al,, ed. (2007). "Definition of "phenology". Appendix I: Glossary. Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press (CUP).

Schneider, SH (2007). "19.3.1 Introduction to Table 19.1". In ML Parry, et al, (eds.). Chapter 19: Assessing Key Vulnerabilities and the Risk from Climate Change. Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press (CUP)

Climate change, agriculture and aid for trade, by Jodie Keane, ICTSD-IPC

Hennessy, K. et al. (2007). "Australia and New Zealand. In: Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [M.L. Parry et al. (eds.)". Cambridge University Press, Cambridge, U.K., and New York, N.Y., U.S.A.. pp. 507–540.

"The Economic Impacts of Climate Change: Evidence from Agricultural Profits and Random Fluctuations in Weather".

F. Woodward and C. Kelly (1995). "The influence of CO concentration on stomatal 2

density". New Phytologist 131 (3): 311–327.

Bert G. Drake; Gonzalez-Meler, Miquel A.; Long, Steve P. (1997). "More efficient plants: A Consequence of Rising Atmospheric CO2?". Annual Review of Plant Physiology and Plant Molecular Biology 48: 609–639.

Loladze, I (2002). "Rising atmospheric CO and human nutrition: toward globally 2

imbalanced plant stoichiometry?". Trends in Ecology & Evolution 17 (10): 457.

Carlos E. Coviella and John T. Trumble (1999). "Effects of Elevated Atmospheric Carbon Dioxide on Insect-Plant Interactions". Conservation Biology (Conservation Biology, Vol. 13, No. 4) 13 (4): 700–712.

The Food, the Bad, and the Ugly Scherer, Glenn Grist July, 2005

Plague of plenty New Scientist Archive

Big melt threatens millions, says UN

202

Physiological Disorders in Vegetable Crops: Causes and Management

Santosh Kumari

Department of Vegetable ScienceDr YS Parmar University of Horticulture & Forestry, Nauni, Solan-173230 HP

Physiological disorders are abiotic abnormalities in leaf and fruit and plant morphology which are not caused by infectious diseases or insects. These abnormalities occur as a result of genetic factors, environmental factors like temperature and relative humidity, unbalanced soil nutrients, moisture stress, poor drainage, improper planting time and harvesting time etc. These disorders decrease the yield in vegetable crops and quality of the produces becomes poor. Different disorders are found in vegetable crops and are as follows:

Tomato

Blossom-End Rot

Lesions appear at blossom end of the fruit while it is green. It begins with light tan, water-soaked areas that can enlarge and turn black and leathery in appearance. Most often the problem occurs at the blossom end of the fruit, but on occasion can occur on the side of the fruit. Many factors can influence this disorder like low soil Ca, high N rates, using ammonical sources of N, high concentrations of soluble K and Mg in the soil, high salinity, low humidity, inadequate soil moisture, excess soil moisture and damage to root system by nematodes etc. This disorder can be controlled by spraying the crop with calcium chloride @ 0.5% at fruit development stage. Apply recommended quantity of nitrogen and give light and frequent irrigations to maintain optimum soil moisture.

Cat face

The fruits with cat face are characterized by the distortion of blossom end of the fruit. Such fruits have ridges, furrows, indentations and blotches. It resembles blossom end rot but is distinct from it. Abnormal growing conditions during formation of blossom appear to cause distortion of growth of the cells of the pistil. As a result, the cells in the blossom end of the ovary die and turn dark to form a leathery blotchy at the end of the fruit without the progress of symptoms characteristic of blossom end rot. For less incidence of this disorder grow tomato crop under favourable climatic conditions.

Puffiness

As the fruit reaches about two third normal size, the outer wall continues to develop normally but remaining internal tissue growth is retarded. As a result, tomato fruits are light in weight, lack firmness and partially filled. This is due to non-fertilization of ovule, embryo abortion after normal fertilization and necrosis of vascular and placental tissue after the fruit

is well developed. Causal factors are high or low temperature and low soil moisture. To control this disorder maintain the optimum soil moisture. Summer grown tomatoes have less incidence of this disorder.

Sunscald

Exposed fruits of tomato either green or nearing ripeness scald readily during extreme heat. The tissue has blistered water soaked appearance. Rapid desiccation leads to sunken areas which usually have white or grey colour in green fruit or yellowish in red fruits. The cultivar in which heavy foliage is characteristic and in which there is greater protection from sun rays usually have least damage. Avoid heavy training and pruning in summer months. Crop can be raised in higher density.

Fruit cracking

Cracking of the surface of the fruit at the stem end is a common occurrence and often results in large losses. The cracks are of two kinds, one which radiates from the stem end and other develops concentrically around the shoulder of the fruit. Radial cracking is more common and causes greater loss than concentric cracking. Besides these, cuticular cracking is also often found of the skin of fruits. Several environmental factors seem to be involved in the cracking. It is common during rainy season when temperature is high, especially when rains follows long dry spell. Radial cracking is more likely develop in full ripe fruit than in mature green or turning stage maturity. On other hand, concentric cracking is relatively low on ripe fruits than mature green. Fruits exposed to sun develop more concentric cracking than those which are covered with foliage. Cultivar Sioux is resistant to fruit cracking.

Gold fleck

Appearance of gold colour flecks on fruits is the main feature of this disorder and chlorophyll is not properly changed in carotenoids (Kalloo, 1986). A fine spotting affects the calyx end of the fruits and sometimes extends over the whole skin. The affected fruits have a shorter shelf life than unaffected ones. This disorder is most commonly found in late crops in glasshouses with little or no heating. A high incidence of the disorder is associated with large differences in temperature and humidity during the day and night, a low K:Ca ratio, low Mg content and a low EC level. High Mg and low P concentrations in the nutrient solution with high EC value will reduce the severity of the disorder. Summer grown tomatoes have less incidence.

Capsicum

Blossom end rot

Disorder is characterized by appearance of water soaked spots on the blossom end of the fruit. They turn light brown and papery as they dry. Causes are Ca deficiency in the soil, moisture stress and heavy fertilization of nitrogen. This disorder can be controlled by spraying the crop with calcium chloride @ 0.5% at fruit development stage. Give light and frequent irrigations to maintain optimum soil moisture and apply recommended dose of nitrogen.

204

Sun scald

Soft, light coloured and slightly wrinkled areas appear on the fruit surface. Later these areas become sunken and papery. It is caused when fruits are exposed to intense light. Disorder can be controlled by transplanting the seedlings at closer spacing. Raise the crop in high density.

Cauliflower

Buttoning

The cause for buttoning of cauliflower has been variously explained by many workers like over aged seedlings, poor nitrogen supply, wrong cultivars etc. While many of these are partly correct, the general basis of buttoning may be explained that any check in the vegetative growth of the seedlings may induce buttoning. Transformation from vegetative to curding in a cultivar of cauliflower is dependent on particular temperature, therefore, the check of vegetative growth followed by suitable temperature for transformation to curding may induce this malady. The check in growth may be caused by low nitrogen supply, when early cultivars are planted late and transform easily due to lower temperature and over aged seedling after establishment don't get sufficient time to initiate growth before transformation.

Riceyness

A premature initiation of floral buds is characterised by riceyness in cauliflower and is considered to be of poor quality for marketing (Wiebe, 1975). Curd becomes granular and loose. This disorder may result from higher temperature or lower than the optimum required for a particular cultivar. Other causes are use of poor quality seed and application of high nitrogen in soil. Grow the crop under favourable climatic conditions to avoid this disorder. Use good quality seed and apply recommended dose of nitrogen

Whip tail

Cauliflower responds to the deficiency of molybdenum. Young plants in a shortage of this element become chlorotic and may turn white, particularly along the leaf margins, they become cupped and wither. Eventually, the leaf dies and the growing point also collapses. In older plants, the lamina of newly formed leaves is irregular in shape, consisting of only a large bare midrib and hence the common name 'whiptail' originated. Apply 0.5-1.0 kg sodium or ammonium molybdate per hectare at field preparation or spray the crop with 0.1-0.3 % ammonium molybdate to reduce the disorder.

Browning

In cauliflower, boron deficiency has been reported very frequently. Till the curds start developing, external symptoms of boron deficiency is not very apparent. The first sign is appearance of small water soaked areas in the centre of the curd. In later stages, the stem becomes hollow with water soaked tissue surrounding the walls of the cavity. In more advanced stages, pinkish or rusty brown areas develop on the surface of the curd and hence it is known as brown rot or red rot. Affected curds develop a bitter taste. This may be controlled

205

by applying borax or sodium borate at the rate of 20 kg per hectare (Datta, 1963). In case of acute deficiency, spray of 0.25 to 0.50 percent solution of borax at the rate of 1 to 2 kg per hectare would give a satisfactory control.

Blindness

Plants remain without terminal buds. Leaves become large, thick, leathery and dark green. It occurs due to damage to terminal buds during transplanting and injured by insects pests. Careful handling should be done at the time of transplanting, Control insects pests timely so that terminal buds may not be injured.

Leafy curd

Leafy curd is characterized by the production of small and green leaves between the curd segments and occurs due to high or low temperature. Varieties should be planted in such a time that their curd formation coincides with optimum temperature requirement.

Cabbage

Cabbage Splitting

Cabbage splitting is mainly a problem with early cabbage. A problem can develop when moisture stress is followed by heavy rain. The rapid growth rate associated with rain, high temperatures and high fertility cause the splitting. Proper irrigation may help prevent splitting and there are significant differences between cultivars in their susceptibility to this problem. Splitting may also be partially avoided by deep cultivation to break some of the plant roots.

Bolting

Premature formation of seed stalk without forming the head is known as bolting. It is commonly found in early cabbage and cause considerable losses to the farmers. It is not desirable in commercial crops but essential in seed production programme. This disorder occurs due to early sowing of seeds in the hot weather, presence of warm winter, sudden and extreme changes in temperature during crop growth and inadequate nutrient supply. Avoid sowing in warm climate. Supply adequate amount of nutrients.

Carrot

Carrot splitting

Roots crack in this disorder due to factors like heavy side dressing with nitrogenous fertilizers, sowing at wider spacing, large size of the roots and fluctuation in soil moisture. Supply recommended dose of nitrogen. Maintain optimum moisture in the soil and harvest the crop at right maturity stage.

Cavity spot

Cavity spot is characterized by appearance of cavity in the cortex and the subtending epidermis collapse to form a pitted lesion. The disorder is caused due to calcium deficiency, increased level of potassium and delay in harvesting. This disorder can be managed by

206

incorporating calcium containing fertilizers in the soil and harvesting the roots at optimum time.

Forking

Many roots arise from the main root and looks like a fork so called forking. This disorder is caused by use of undecomposed farm yard manure and growing crop in hard soil pan. Use friable soil for planting and use well decomposed farm yard manure to control the disorder.

Greening

Roots turn slightly green in colour when exposed to direct sunlight and are unfit for consumption. Earthing up should be done to avoid the exposure of roots to direct sunlight

Potato

Black or hollow heart

Central tissues of the affected tubers show black discoloration due to sub oxidation (black heart. In advanced stage of this disorder, the affected tissues dry and separate to form cavities brought about by very rapid growth of tubers and called as hollow heart. The symptoms are internal, therefore it can be seen only after cutting the tuber. High soil moisture during growth and maturity of the tubers favours this disorder. Unfavourable oxygen supply during storage and transport and storage of tubers at high temperature are other causes this disorder. To control the disorder provide ventilation in storage and during transportation. Store tubers in cold storage at lower temperature.

Greening

Tubers turn green in colour when exposed to direct sunlight. The green pigment produced is Solanin which is slightly poisonous and make the tubers unfit for consumption. Earthing up should be done to avoid the exposure of tubers to direct sunlight.

Sprouting in storage

Sprouting of potato tubers in storage is the major problem of storage which deteriorates the quality and make the product unfit for consumption. The intensity of sprouting depends on the variety, maturity, storage temperature and relative humidity. Store

0 potato in cold storage at 2-4 C temperature and 90 95 percent relative humidity.

Onion

Bolting

It refers to the emergence of seed stalk prior to time of their formation and adversely affects the formation and development of bulbs. Bolting is an undesirable character because it directly affects the bulb yield of onion. Early transplanting and late transplanting induce bolting in kharif and rabi onion respectively. White cultivars are more sensitive to bolting. Transplanting of aged seedlings and poor supply of nitrogen in the soil are others reasons of bolting.

207

Sprouting of bulbs

This disorder is one of the important disorders in storage and causes a huge loss to farmers. It is found in both onion and garlic. Sprouting in white cultivars is reported more commonly than in pink or purple cultivars. Sprouting is also associated with excessive soil moisture at maturity ad supply of nitrogen. To control this disorder adjust sowing time in such a way that harvesting can be done in dry period. Withhold irrigation as soon as bulbs reach to maturity. Apply recommended dose of nitrogenous fertilizers and grow purple or pink coloured cultivars.

Lettuce

Tip burn

Disorder is characterized by appearance of tip burning of margins of the inner leaves of mature heads. The disorder is common in greenhouse grown crop than open field crop. This is caused due to prevalence of high temperature, excess of nitrogen, calcium deficiency Spray the crop with Calcium Chloride at rate of 0.5 percent and apply recommended dose of nitrogen.

References:

Bose, T K, Som M G and Kabir J.Vegetable Crops. Naya Prokash Calcutta.

Chaudhary A K, Fageria M S and Arya P S. Vegetable Crops Production Technology. Kalyani Publishers.

208

Weed Management in Vegetable Crops

Dharminder Kumar, Manish Kumar, Ramesh Kumar, KS Thakur, Amit Vikram* and Sandeep Kumar

Department of Vegetable Science,*Directorate of Extension Education

Dr YS Parmar University of Horticulture & Forestry-Nauni (HP) 173230

INTRODUCTION

Weed is a plant out of place or growing where it is not desired. The vegetable fields are usually infested by a wide spectrum of broad and grassy weeds. Weeds compete with the crops for water, soil, nutrients, light, space and thus reduce crop yields up to 37 per cent (Varshney, 2009). They also harbour many insect-pests and microorganisms (Cooper and Harrison, 1973). On an average weed extract two times more N and Ca and 25 per cent more potassium than the crop (Mallik et al. 1998). Reduction in economic yield of vegetables has been reported to be 6-82 per cent in potato, 25-30 per cent in peas, 70-80 per cent in carrot, 67 per cent in onion, 42-71 per cent in tomato and 61 per cent in cauliflower (Singh et. al., 1993). Conventional methods of weed control have become an expensive input in the cultivation of vegetable crops. Owing to high cost and non- availability of labor, in time and no single method of weed control is adequate or cost effective. Integrated weed management is a systematic approach to minimize weed impacts and optimize the land use, by the use of different weed management practices (Aldrich, 1984).

Weed flora associated with vegetable crops

In Rabi Season:

Botanical name Common name Family Chenopodium album Bathu Chenopodiaceae Melilotus indica Senji Methi Papilionaceae M. Alba

Ban methi

Papilionaceae

Lathyrus aphaca

Maturi, Pipura Pipari

Papilionaceae

Vicia sativa

Anhta ankari

Papilionaceae

Convolvulus arvensis

Hirankhuri

Convolvulaceae

Rumex maritimus

Panbheri

Polygonaceae

Cynodon dactylon

Bermuda grass, Doob grass

Graminae

Cyperus rotundus

Motha

Cyperaceae

Orobanche spp.

-----

Orobanchaceae

Spergula arvensis Bhandhania CaryophyllaceaeEuphorbia hirta Bari Dudhi Euphorbiaceae

In Kharif Season:

Approaches for integrated weed management

A. Preventive weed management

·Use clean seed. As many weed seeds get mixed with the main crop and these seeds should be separate before sowing to avoid weeds.

·Clean tillage implements. Many weed seeds stick to the implements used in the previous crops, so before using these implements these should be thoroughly cleaned.

·Avoid use/transportation of soil from weed infested area

·Prevent reproduction of weeds by removing then in vegetative stage.

·Use weed seed screen filter irrigation water to avoid weed seeds dispersal through irrigation water.

·Restrict live stock movement to non weed infested area. Many weed seeds get stick to live stock and

·Use thoroughly decomposed organic manure, because many seeds remains vival in the cattle dung and if it is used in the fields undecomposed then these weed seeds will germinate.

·Weeds should be removed from the fields before the critical crop weed competition period to avoid yield losses.

Botanical name Common name Family Trianthema portulacastrum Patharchata, Gadhupura Azoiaeae Echinochloa colona Barnyard Grass, Sama grass, Graminae Cyperus rotundus Motha Cyperaceae Digeria arvensis ----- Amaranthaceae

Amaranthus viridis Jangli Chaulai Amaranthaceae Physalis minima Ban Makaya Solanaceae

Phyllanthus niruri Haizardana Jar-Amla bhuin Anmala

Euphorbiaceae

Commelina benghalensis Kanna, Kena Commelinaceae Eleusine indica Malanpuri Kodai Graminae

Ageratum conyzoides Neela phool Compositae Cynodon dactylon Bermuda grass, Doob grass Graminae Celosia argentea Safed murge ka phool, Suawari Amaranthaceae

210

Critical stages for crop-weed competition in Vegetable crops

B. Cultural practices

• Stale seed bed ,Mixed cropping ,Land preparation ,Mulching, Hand weeding ,Burning and flaming ,Crop Rotation, Irrigation and Solarization

Stale seed beds

• Stale ('false') seed beds are sometimes used for vegetables when other selective weed-control practices are limited or unavailable. Success depends on controlling the first flush of emerged weeds before crop emergence, and on minimal disturbance, which reduces subsequent weed flushes. Basically, this technique consists of the following:

• Preparation of a seedbed 2-3 weeks before planting to achieve maximum weed-seed germination near the soil surface.

• Planting the crop with minimum soil disturbance to avoid exposing new weed seed to favourable germination conditions.

• Treating the field with a non-residual herbicide to kill all germinated weeds (William et al. 2000) just before or after planting, but before crop emergence.

Crop rotation

Crop rotation was considered for a long time to be a basic practice for obtaining healthy crops and good yields. Classically, crop rotations are applied as follows:

1. Alternating crops with a different type of vegetation: leaf crops (lettuce, spinach, cole), root crops (carrots, potatoes, radish), bulb crops (leeks, onion, garlic), fruit crops (squash, pepper, melon).

Crops Critical Stage (DAS/DAP)

Developmental Stage

Onion/Garlic 30-75 Bulb Initiation Cabbage/Cauliflower 30-45 Head initiation Okra 15-30 10-15 cm tall Tomato/Chilli 30-45 20-33 cm tall Brinjal 20-60 ---- Beans ---- Canopy Formation Potato/Radish 25-30 ---- Carrot 15-20 7-10 cm tall

Source: Singh et al. (1993)

211

2. Alternating grass and dicots, such as maize and vegetables.3. Alternating different crop cycles: winter cereals and summer vegetables.4. Avoiding succeeding crops of the same family.5. Avoiding problematic weeds in specific crops (e.g. Malvaceae in celery or

carrots, parasitic and perennials in general).

Soil Solarization

Soil solarization is a preventive method that exploits solar heating to kill weed seeds and therefore reduce weed emergence. Solarization can be defined as a soil disinfection method that exploits the solar energy available during the warmest period of the year. To increase the solarization effect as much as possible, the soil surface must be smooth and must contain enough water to favour heat transfer down the profile and to make reproductive structure of pests, diseases and weeds more sensitive to heat damage. For this reason, prior to solarization the soil is usually irrigated and a plastic mulch film is laid down onto the soil to further increase soil heating and to avoid heat dissipation to the atmosphere. The soil solarization can only be used in warm climates or under glasshouse conditions in warm-temperate and Mediterranean climates. For example, a significant reduction in weed emergence was observed over the following 12 months after one-month's solarization in a tunnel glasshouse used for vegetable production in Central Italy (Temperini et al. 1998).

Land preparation and tillage

When annual weeds are predominant the objectives are unearthing and fragmentation. This must be achieved through shallow cultivation. If weeds have no dormant seeds deep ploughing to bury the seeds will be advisable. The success of many weed-control operations depends upon the timing of its implementation. The opportunity for mechanical operation is indeed essential. Action must be taken against annual weeds before seed dispersion takes place.

Hand weeding

It is very efficient for annual weeds, but not for perennial capable of vegetative reproduction, because root separate from shoot that then produce a new shoot. Hand hoeing control the persistent perennials if it is done often enough. Although efficient and widely used, it takes a lot of time and human energy.

Flaming0Thermal death points for most plant tissue are between 45–55 C after

prolonged exposure. A flamer directs a petroleum based fuel emitted under pressure and ignited. Plant size at treatment influences efficacy much more than plant density.

212

Required dose increased with plant growth stage and some species of annual weeds are more tolerant than others. The most tolerant species cannot be controlled with one flaming, regardless of dose.

Mulching

It excluded light and prevents shoot growth. Mulches increase soil temperature and many promote better plant growth. Several different materials have been used to mulch, including straw, hay, manure, paper and black plastic. Mulches are used in high value crops.

C. Chemical weed control

Advantages:-

• Herbicides are not beneficial but profitable where labour is scarce or expensive.

• Control weeds in crop rows where cultivation is not possible.• Pre-emergence herbicides provide early season weed control when

competition results in the greatest yield reduction and when other methods are less efficient.

• Herbicide reduces the destruction of soil structure by decreasing the need for tillage.

• They reduce fertilizers and irrigation requirements by eliminating competing weeds.

Disadvantages:-

• Some herbicide persist in the environment • Undeniable mammalian toxicity• Selective herbicides control some weed only• Are often inconsistent in weed control• Have phytotoxicity effect

Methods of Herbicide application

Pre-planting/Pre-sowing :- the herbicides are applied in the seed-bed or in the field, incorporating in the soil, usually 20-30 days prior to planting or transplanting in the main field, so as to kill most of the weed seeds.

Post-planting:- the herbicides are sprayed after planting the crop.

Pre-emergence:- the treatment is made prior to the emergence of specific weeds. Mostly contact herbicides are used in this method. The weedicides are applied after the weeds have emerged before the crop emergence and used an efficient herbicide that does not persist in toxic form in the soil.

213

Post-emergence:- the treatment is given after the emergence of specific crop or weed; especially post-emergence of the crop.

Classification of herbicides:

1. On the basis of chemical

1a. Inorganic

1b.Organic herbicides

Group Chemical Acids Sulphuric acid, Arsenic acid Chlorate Sodium chlorate, Borax, Decahydarate, Sodium

metaborate Sulphamate Copper sulphate, Ferric sulphate AMS Ammonium sulphamate Nitrate Sodium nitrate

Group Herbicide Name Aliphatics Dalapon,TCA Amides and Anillides Alachlor, Butachlor, Propachlor, Propanil, Naptalam,

Acrolein Anilines and Nitro -phenols

Dintramine, Nitralin,Triflutrlin, Fluchoralin, Nitrofen

Arsenicals DSMA, MA, MSMA Benzoics and Phenyl Acetic Acid

Chloramben, Dicamba, Fenac

Carbamate Diclormate, Asulam, Barban, Propham Thio-Carbamate Benthiocarb, EPTC, Diallate, Tra -allate, Molinate,

Glyphosate Heterocyclic Compounds

Bipyridyelium, Pyridines, Pyridazines, Uracils, Atrazine, Simazine, P ropazine, Ametryne, Promatone, Terbutryn, Metribuzin

Hormone Phenoxy acetic acid, Phenoxy propoinic acid, Phenoxy butyric acid

Nitriles Bromoxynil, Dichlobenil, Loxynil Substituted Urea Chloroxuron, Diuron, Fenuron, Fluomrturon, Monuron Alkoxy Liuron, Chlorbromuron, Neburon Unclassified Methazole, Perfluidon, C-288 Nitriles Bromoxynil, Dichlobenil, Loxynil

Source: Brian (1964)

214

2. On the basis of selectivity

2a. Selective: those herbicides which affect only certain weeds, leaving certain crops unharmed. But the selectivity depends on the amount of chemical applied and the way they are used.

2b. Non - selective: are used to control a wide range of vegetation indiscriminately because they are toxic to all plants and highly susceptible to living plant tissues

Commonly used Herbicides in Vegetables:

Selective Herbicides for Weed Control in Vegetable Crops:

Common Name

Trade Name Time of application

Rate (kg/l/ ha)

Usages

Alachlor Lasso Pre- 2-3 Selective Atrazine

Atrataf

Pre-

0.5-2

Selective

Borate

Hibour,Monobar

Soil pre/post

2-3

Non-selective

Butachlor

Machete

Pre-

1-2

Selective Fluchloralin

Basalin

Pre-

1-2

Selective

Gluphosate

Round up

Post

1-2

Non-selective Metribuzin

Lexone, Sencor

Pre-

0.25-1

Selective

Nitrofen

Tok-E-25

Pre/post

2-5

Selective Oxadiazon

Ronstar

Post

0.75-4

Selective

Paraquat

Gramaxone

Post

0.5-1

Non-selective

Picloram

Tordon,Amdon

Pre/post

2-4

Selective

Diquat

Reglone

Post

1-2

Non-selective

Simazine

Gesatop

Pre

Selective

Herbicides

Dose

(kg/ ha)

Treatment

Crops

Pendimathelin

0.65-1.0

Pre-emergence

Transplanted pepper, onion,garlic, spinach brassica crops, umbelliferous crops, legumes

and potato.

Fluchloralin/

Trifluralin

1.0-1.5

Pre plant -incorporation

Transplanted tomato, pepper, brinjal, potato, okra, brassica crops, legumes, garlic and umbelliferous crops.

Oxyfluoren

0.24-0.36

Early post -emergence

Direct seeded and transplanted

onion and potato.

Butachlor

2.0

Pre-emergence

Transplanted tomato & cucurbits.

Metribuzin 0.2-0.35 Pre or post emergence

Direct seeded and transplanted tomato and potato.

215

Biological weed control:

It is defined as the action of the parasite, predators or pathogens in maintaining ,

other organisms population at a lower average density than would occur in their absence. The term was used by H. S. Smith .

Bio-control agents:

Classical or inoculative: It has been used for many years. The earliest record of biological weed control was the release of cochineal insect Dactylopius ceylonicus from Brazil to north india in 1795 to control prickly pear cactus.

Inundative or Augmentative: e.g. Fungi (Colletotrichum gloeosporioides)

Broad spectrum: Fish (e.g. White amur or Grass carp (Ctenopharyngodon idella Valenciennes), Aquatic Mammals e.g. Sea manatee (Trichechus spp.) and Vertibrates e.g. Sheep, goats etc.

Examples of promising bio-agents in weeds

Conclusion

Weed control work has to be intensified in important vegetable crops to obtain maximum yield.Greater attention must be paid to integrated weed control practices instead opting a single practice. A careful watch has to be kept in places

Weed Bioagent Reporting Country

Kind of Bioagent

Chondrilla juncea Puccinia chondrillina Australia Plant Pathogen Cirsium arvensis Septoria cirsii Plant Pathogen Cyperus rotundus Bactra verutana India,

Pakistan & USA

Shoot boring moth

Eupatorium riparium Entyloma compositarum USA Plant pathogen Hydrilla verticillata Hydrillaq pakistanae USA Shoot fly Orobanche cermua Sclerotina spp. USA Plant pathogen Parthenium hysterophorus

(i) Zygograma bicolorata

(ii) Epiblema sternuana

(iii)Conotrachelus spp.

India Australia Australia

Leaf eating insect Stem galling insect Stem galling insect

Rumex spp. (i) Uromyces rumicis

(ii) Gastrophysa viridula

USA USA

Plant pathogen Beetle

Source: Parsad and Kumar (1999)

216

where one particular herbicide is being used continuously for a long time, because it may lead to growth of resistant weed species. Herbicide mixtures must be kept handy to control these resistant species. Extension services should be provided to farmers, so that the production system becomes more profitable.

Reference:

Aldrich RJ.1984.Weed crop ecology: principles in weed management. Berton Publishers. Massachusetts.375p.

Brian RC.1964.The metabolism of herbicides. Weed research 4(2):105-107.

Cooper JI and Harrison BD. 1973. The role of weed host and the distribution and the activity of nematodes in the ecology of tobacco rattle virus. Annals of Applied Biology 73:53-66.

Kudarimani HB.1977. MSc(Ag.)Thesis.University of Agricultural Sciences, Bangalore.

Mallik RK, Yadav A and Rana MK. 1998. Farmers and parliament, December Issue.

Pleasant JM and Schlather KJ.1999.Weed Technology 8:304-310.

Prasad S and Kumar U.1999. In:Principle of horticulture, Agro Botanica. pp. 429-430.

Singh K, Panda MC and Jhakaral KK.1993.Preceding of International Symposium. Indian Society of Weed Science, Hisar 1:365-368.

Temperini O, Bàrberi P, Paolini R, Campiglia E, Marucci A and Saccardo F. 1998. Solarizzazione del terreno in serra-tunnel: effetto sulle infestanti in coltivazione sequenziale di lattuga, ravanello, rucola e pomodoro. In Proc. XI SIRFI Biennial Congress, Bari, Italy. 12-13 November, 213-228 (Italian, with English abstract).

Varshney JG.2009.Why weed control. Crop Care 35(10):13-25.

William RD, Ball D, Miller TL, Parker R, Yenish JP, Miller TW, Morishita DW and Hutchinson P. 2000. Weed management in vegetable crops. Pacific Northwest Weed Control Handbook. Extension Services of Oregon St. University, Washington State University and University of Idaho. USA.pp.244-274.

(also available at http://weeds.ippc.orst.edu/pnw/weeds).

Yaduraj NI and Dubey RP.2002.Compedium of lactures in winter school of recent advances in vegetable Production Technology held at IIVR, Varanasi, From 3-23 December,2002.pp. 121-126.

Zaragoza C, Branthome X, Portugal JM, Pardo A, Suso M, Rodríguez A, Monserrat A, Tiebas A, Fernández S and Gutierrez M. 1994. Itineraires techniques compares pour le controle des mauvaises herbes chez la tomate en differentes regions europeennes.

th5 EWRS Mediterranean Symposium. Perugia, Italy. pp. 179-186.

217

Biochemical Constituents and Quality Attributes in Spices

Vipin Sharma and H Dev Sharma

Department of Vegetable ScienceDr YS Parmar University of Horticulture & Forestry, Nauni, Solan-173 230

The spices are natural products of plant origin, used primarily for flavoring, seasoning or for adding pungency to foods and beverages. They stimulate secretion of digestive juice. In addition to these, spices have been known for many different applications from ancient times, like as medicaments, disinfectants, insect repellents, fragrances etc. Some essential oils in the spices are used as natural insecticides or bio-insecticides. Some of the volatile compounds of spices affect the olfactory centers and taste buds. Spices like chilli, turmeric and tamarind possess antioxidant properties while others like ajwain, fennel and ginger are used as carminatives. Some spices like clove and mustard possess strong anti-microbial properties and as such prevent food spoilage. Seed spices like coriander, cumin, fennel, fenugreek etc play an important role in cuisine and in combating human ailments. In view of these facts, all traditions of Indian culinary systems adopted spices in their regular diet and used them widely as seasonings. Spices contain variable amounts of proteins, fats, carbohydrates, fibres, minerals and vitamins. However, owing to the very small quantity used in the food, their contribution to the nutrient requirement is not significant. Proteins, carbohydrates, minerals and vitamins are thus relatively less important in delineating the quality of spices. Earlier the plant breeders in India focused on higher yields, resistance/ tolerance to biotic and abiotic stresses and to some extent the physical aspects of quality i.e. shape, size, texture, colour, tenderness etc. but now as the people are becoming more and more aware about the medicinal properties of spices, main emphasis is given to the biochemical quality which includes: dry matter, flavour, alkaloids, flavanoids and volatile oils etc. The increasing quality consciousness in our country as well as in European and other developed countries will demand more improvement of quality in future. This increase in demand of spices through out the world has led to more production of spices by which our produce can penetrate the foreign market with superior quality products. Further, to maintain our historical position in the international spice trade we have to give stress on the quality aspects of spices. Keeping this in view, the biochemical constituents and the quality attributes of some important spices are discussed.

A) Major spices: 1) Ginger: Ginger is composed of fibre, protein, fat, starch, ash, essential oils and other components and each component has a number of

SrNo Components Ginger Turmeric Black pepper CardamomCarbohydrate

(g)

12.3

69.4

66.5

-

Protein

(g)

2.3

6.3

10.0

-

Fibre

(g)

2.4

2.6

14.9

6.7Water

(g)

80.9

13.1

8.0

7.0

Food Energy (Kcal) 67.0 - 4000.0 - Fat (g) 1.0 5.1 10.2 - Calcium (mg) 20.0 150.0 0.4 0.3Phosphorus (mg) 60.0 262.0 160.0 0.215Sodium

(mg)

-

-

10.0

0.015Potassium

(mg)

-

-

1200.0

1.2Iron

(mg)

3.5

148.0

17.0

0.012

Thiamine

(mg)

0.06

-

0.07

0.18Riboflavin

(mg)

0.03

0.03

0.21

0.235Niacin

(mg)

0.60

-

0.8

2.3Vitamin-C

(mg)

6.0

-

-

12.0

1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16. Vitamin-A (IU) - - 19.0 175.0

compounds. The chemistry of ginger has been the subject of sporadic study since the early nineteenth century. Ginger owes its characteristic organoleptic properties to gingerols. The odour and much of the flavor of ginger is determined by the constituents of its steam volatile oil, while the pungency is produced by non-volatile components known as gingerols, the essential oil is comprised mainly of mono and sesqui-terpene hydrocarbons and oxygenated compounds. The mono-terpene constituents, though present in trace amounts, contribute most of the aroma of a ginger volatile oil of which chief constituent is a sesqui-terpene, called zingiberine (C H ). The pungent principle of ginger is zingerone (C H O ) which is present in 15 24 11 14 3

the oleoresin. The essential oil contains á-pinene, camphene, â-pinene, myrcene, limonene, 1, 8-cineole, â-phellandrene, p-cyme, methyl-hepatanone, nonanal, decanal, neral, geraniol, 2-nonanol, linalool, bornyl acetate, d-borneol, geraniol, á-selinene â-elemene, â-zingiberene, â-bisabolene, arcurcume and â-farnesene.

Table: 1 Chemical composition of major spices (per 100 grams edible portion)

2) Turmeric: Turmeric occupies an important position in the life of Indian people as it forms integral part of the rituals, ceremonies and cuisine. Due to the strong antiseptic properties, it has been used as a remedy for all kinds of poisonous affections, ulcers and wounds. The recent research have been focused on its antioxidant, heptoprotective, anti-inflammatory, anti-carcinogenic and anti-microbial properties, in addition to its use in cardiovascular diseases and gastrointestinal disorders. It gives good complexion to the skin and so it is used as a facial tonic. The drug cures diseases due to vata, pitta and kapha. The essential oil contains ar-turmerone and ar-curcumene as major constituents. Some of other compounds are á and â-pinene, sabinene, mysene, á-terpinene, limonene, p-cymene, perillyl alcohol, turmenone, lugenol, iso-eugenol, eugenol methyl ether and iso-eugenol methyl ether. Curcumin and related compounds have also been reported as

219

major constituents of the rhizomes. Curcumin (diferuloymethane) is responsible for the yellow colour, and comprises curcumin I (94%), curcumin II (6%) and curcumin III (0.3 %). Recently a number of sesqui-terpenes have been reported from turmeric.

3) Black pepper: Black pepper the king of spices is valued for its characteristic pungency and flavour and hence used extensively as a spice and condiment in a vast variety of food preparations. Pepper is an important ingredient in traditional medicines too. Its quality depends upon the sum total of the chemistry of its pungency and flavour components. Its flavour or aroma is due to the essential oils present in the fruit; while the pungency is due to the alkaloid piperine. The major compounds in the essential oil consist of mono and sesqui-terpene hydrocarbons and oxygenated compounds. In addition to these 27 miscellaneous compounds are also present. They are: eugenol, methyl eugenol, myristicin, safrole, benzaldehyde, transane thiole, piperonal, m-methyl acetophone, p-methyl acetophone, n-butyrophenone, benzoic acid, phenyl acetic acid, cumanic acid, piperonic acid methyl hepatonene, pinol, butyric acid, 3-methyl butyric acid, hexanoic acid, 2-methyl pentanoic acid, methyl heptanoate, methyl octanoate, 2-undecanone, n-nonane, n-tridecane, n-nondecane and piperidine.

4) Cardamom: Cardamom the queen of spices is used for flavouring various food preparations, confectionery, beverages perfumery and liquors. It is also used for medicinal purpose, both in Allopathy and Ayurveda systems. In the Middle East countries it is mainly used for Gahwa, a special cardamom-flavoured coffee. The seeds are used as antidote to snake and scorpion venom. The extract is also used as a fish poison. The composition of cardamom varies slightly with the variety, region and age of the product. The Indian cardamom seeds contain volatile oil, ashes, non-volatile ether extract, crude fibre, crude protein, starch, calcium, phosphorus, sodium, potassium, iron and vitamins A, B , B and C. 1 2

B) Seed spices: 1) Coriander: A pleasant aromatic odour is present in the stem, leaves and fruits of coriander, which is due to an essential oil containing mainly linalool or coriandrol. It is considered to be carminative, diuretic, stomachachic, tonic, antibilious, refrigerant and aphro-disiac. Dried ripe coriander fruit contains both steam volatile oil and fixed oil. The aromatic odour and taste of coriander fruit is due to its volatile oil. Coriander oil is clear, colourless to light yellow liquid. Oil content of seeds varies widely with geographic origin. High volatile oil content is found in Norwegian coriander (1.4-1.7%) followed by Bulgarian coriander (0.1-0.5%). Indian seeds are poor in oil content (0.1-0.4%). The major component of essential oil is linalool, followed by á-pinene, gamma-terpene, geranyl acetate, camphor and geraniol. Minor components include â-pinene, camphene, myrcene, limonene, p-cymol, dipente-terpinene, n-decylaldehyde, bornol and acetic acid esters.

220

2) Fenugreek: Historically used for medicinal purposes, fenugreek seed contains: moisture, protein, fat, crude fibre, carbohydrate and ash. The seeds also contain volatile oil and rigogenin, neorigogenin, diosgenin, yamogenin and gitogenin. Diosgenin content in its seed varies from 0.78-1.90% depending on genotypes as well as on cultural practices. Volatile oil content of the seed is very low and not commercially recovered. Solvent extraction yields the oleoresin with strong, maple-like aroma and bitter taste. Roasting the seeds serves to integrate a pleasant and camellic flavour with the basic bitterness, which is attributed to the presence of two alkaloids, trigonelline and choline. Steroid saponins isolated from the seed are reported to reduce plasma cholesterol levels, enhance food consumption and motivation to eat. Fenugreek saponins serve as the source for three important sapogenins diosgenin, gitogenin and tigogenin, which have immense nutraceutical value. Soluble dietary fiber composed of the polysaccharides, galactomannan, is yet another isolate from the seed. Oleoresin is used in the preparation of imitation maple flavour, rum flavours and as a flavouring agent in pharmacy. It also finds application in seasonings for the processed meat and curry-mixes. Its saponins and fibers are ingredients in health/ functional foods and pharmaceuticals.

3) Cumin: An export oriented seed spice, cumin contains acid insoluble ash, volatile oil and total ether extracts. The cuminaldehyde, the principal aldehyde, constitutes 25-35% á and â-pinene, limonene, p-cymene, perillaldehyde, anisaldehyde, dihydrocuminaldehyde, cuminyl alcohol and a number of minor constituents are also reported.

Sr No Components Coriander Fenugreek Cumin Fennel Dill Ajwain1. Carbohydrate (g) 56.5 44.1 44.6 60.8 56.4 24.62. Lipid (g) 19.6 - 23.8 10.0 17.9 -3. Protein (g) 12.3 26.2 17.7 9.5 13.1 17.14. Fibre (g) 31.5 7.2 9.1 18.5 20.7 21.25. Water (g) 6.3 13.7 6.2 6.3 6.6 7.46. Food Energy (cal)

450

333

460

370

435 363

7. Ash (g) 5.3

-

7.7

13.4

6.0

-8. Calcium (g)

0.8

3.0

0.9

1.3

1.6 7.9

9. Phosphorus (g)

0.44

3.0

0.45

0.48 0.21

7.9

10. Sodium (g)

0.02

3.0

0.16

0.09 0.01

7.9

11. Potassium (g)

1.2

3.0

2.1

1.7

1.1 7.9

12. Iron (g)

59.5

3.0

47.8

11.1 11.8

7.9

13. Thiamine (mg)

0.26

0.34

0.73

0.41 0.42

0.21

14. Riboflavin (mg)

0.23

0.29

0.38

0.36

0.28

0.2815. Niacin (mg)

3.2

1.1

2.5

6.0

2.8

2.116. Vitamin-C (mg)

12.0

-

17.2

12.0

12.0

-17. Vitamin -A (IU)

175

-

175

1040

175

-

221

4) Fennel: The seeds of fennel, a stout aromatic plant are used as stimulant, carminative and in the cure of colic pains and also for mastication and chewing alone or with betel leaves. Two types of fennel are recognized- common fennel and sweet fennel. Common fennel usually contains volatile oil in the range of 2.5-6.5% depending upon the plant origin. The oil is a colourless to pale yellow liquid with an aromatic, spicy odour. The oil of this fennel contains á-phellandrene, pinenes, anethole and methyl chavicol. Sweet fennel is mainly cultivated in South Europe i.e. France & Italy. The essential oil is a yellowish green liquid with characteristic arise odour. The main constituents are anethole and fenchone. The other constituents are methyl chavicol, á-pinene, camphe á-hellandrene and dipentene. Fennel oil and oleoresin are used in pizza sauces and topplings non-alcoholic beverages, baked goods, condiments, ice-creams and liquors and in seasoning for processed meats. Oil is also used to scent soaps and perfumes and to flavour carminative medicines.

Conclusion: The relative importance of quality is dependant upon the end use of the spices. Earlier the quality parameters were appearance, size, shape and presence of extraneous matter. Later, the analytical parameters as described above for each spice, biochemical constituents and quality attributes like ashes, volatile oil content, oleoresin contents, etc. were added to ensure the authenticity and purity of the product, which is depending upon the variety, agro-climatic conditions existing in the area of production, harvest and post harvest operations. Keeping in view the excellent scope for the value added products; development of entrepreneurs with developed technologies, which are commercially viable and infrastructure development and development of human resources are opportunities which can be availed by assuring the quality of spices.

References:

Agrawal, S.; Sastry, E.V.D. and Sharma R.K. 2001. Seed Spices-Production, Quality, Export. Pointer Publishers, Jaipur 302 003 (Raj) India.

Pruthi, J.S. 1998. Spices and Condiments, Natioan Book Trust, New Delhi India.

Ravindran, P.N.; Nirmal Babu, K.; Shiva, K.N. and Kallupurackal, J.A. 2006. Advances in Spices Research, Agrobios, Jodhpur-342 002 (Raj) India.

222

Techniques of Quality Analysis in Spices

Vipin Sharma and H Dev Sharma

Department of Vegetable ScienceDr YS Parmar University of Horticulture & Forestry, Nauni, Solan-173 230

Spices and condiments relate to the natural, aromatic plant components or mixture thereof, used for flavoring, seasoning and imparting aroma or flavor to the food. Ancient peoples such as the Egyptian, the Arab and the Roman made extensive uses of spices, not only to add flavor to foods and beverages, but as medicines, disinfectants, incenses, stimulants and even as aphrodisiac agents. Some of them possess antioxidant properties, work as preservative in pickles and chutneys and have anti-microbial and antibiotic activities. Spices intensify salivary flow and the secretion amylase. Saliva rich in ptyalin facilitates starch digestion in stomach, rendering the carbohydrates rich meal more digestive. Spices clean oral cavity from food adhesion and bacteria. Internationally, there are about 70 plant species that have been grown for spices, the majority of which are in Asia. Therefore Asia is known as the 'Land of Spices' as it is the place of origin, production, consumption and export of most spices. 13 are considered major spices produced in Asia i.e. black pepper, cardamom, cinnamon, cassia, chilli pepper, cloves, coriander, cumin, garlic ginger, nutmeg, turmeric and vanilla. Spices are traded in different forms such as whole, essential oils, powered form or variety of mixtures. It is a good source of income for the farmers. Spices influence our health as they enrich our diet by supplying minerals, vitamins and other components. Iron is supplied by cumin, coriander, fenugreek, turmeric, black pepper, tamarind etc. Calcium is available from cumin, coriander, pepper, clove, turmeric, and asafoetida. Although spices are not very good sources of vitamins but coriander, pepper, chilli, cumin are sources of vitamin-A, chilli and garlic are suppliers of vitamin-C. Turmeric is consumed with boiled milk by woman during postnatal period as a nutritious drink. The ancient Aryans considered spices as a powerful remedy for various disorders in human beings. Even today, unani, homeopathy and ayurvedic system of medicines most of the spices are used as ingredients in medicinal drug preparations. Nutmeg, vanilla, clove, pepper, cumin, celery etc and their oils are used in perfumery or in soap making. Turmeric is used for dyeing. Turmeric, clove, fenugreek, nutmeg are used for manufacture of vanishing cream, toothpaste, hair tonic etc. Dry ginger and ginger powder is used for manufacturing of brandy, wine and beer.

New developments and emerging opportunities: There is some positive developments world over promoting the growth of spice industry:

1. Increasing awareness about naturality of spices and its substitution for synthetic coloring and flavoring agents.

2. Increasing demand on spicy and ethnic food items of countries like India, China, Mexico etc.

3. Emergence of nature food, yogic food, organic food and emphasis on back to nature.

4. Multinational food chain is changing the taste of the world through their spicy menus.

5. Consumers in developed countries are accepting health claims for spices and herbs in countries of origin.

6. Arrival of a hot trend i.e. an increased consumption of hot spices like pepper, chilli, ginger.

Techniques of quality analysis: In order to assess the quality of spices we require following techniques, as awareness to use quality products is increasing day by day.

1) Preparation of sample: Grind laboratory sample as quickly as possible in a grinding mill to pass sieve with 1 mm diameter aperture. Avoid undue heating of apparatus during grinding. Mix carefully to avoid stratification (layering). Store in a dry stoppered container.

2) Determination of extraneous matter and other refractions in whole spices: Thoroughly mix the sample and weigh 100-200 gm depending on the nature of the material (10-20 g in case of small sized spices) and spread in an enameled tray. Separate extraneous matter and other refractions by hand. Weigh each fraction and calculate percentage.

3) Microscopic examination of spices: A water slide should be first prepared by dissolving finely powdered sample with a drop of alcohol and then adding one or two drops of glycerol solution (30% in water) before sliding on the cover slip. The water slide is particularly suitable for detecting starch. The presence of starch can be confirmed by adding a drop of very dilute solution of iodine which produces the usual dark blue colour. Some spices namely cumin, coriander, chillies and cloves do not contain true starch and the presence of extraneous starch can be easily detected in these powdered spices. A cleared slide is prepared by gently boiling the material with chloral hydrate solution (prepared by warming 80 g of crystals in 50 ml water) in a tube until the particles look fairly transparent. Chloral hydrate has two fold action i) it removes starch thereby concentrating other tissues and ii) it removes coloring matter from the tissues so that the outlines can be seen much more clearly. Sclerenchymatous matter can be stained red by warming the cleared material with excess of phloroglucinol solution (1% in 90% alcohol) followed by a drop of conc. HCl.

4) Determination of moisture by Dean and Stark toluene distillation method: The amount of water is determined by distilling the material with an organic liquid (Toluene) not miscible with water and collecting the distillate in a graduated tube. Saturate with small quantity of water and distill. Use the distillate for determination of moisture.

224

5) Determination of total ash: Weigh to the nearest 0.001 g about 2 g of the prepared sample into the tared dish. Pour about 2 ml of ethanol on the material and ignite it. When the ethanol is burnt off, heat the dish carefully over a small flame to char the material.

0Then ignite in a muffle furnace at 550+25 C for 2 hours. Cool and wet the ash with a few drops of water, evaporate carefully to dryness and heat in the muffle furnace for a further 1 hour. If the wetting shows the ash to be carbon free, remove the dish to desiccator containing an efficient desiccant, allow to cool and weigh without delay. If the wetting shows presence of carbon, repeat the wetting and heating until no specks of carbon are visible and ignite in the muffle furnace for 1 hour after the disappearance of carbon. If carbon is still visible, leach the ash with hot water, filter through ash less filter paper, wash the filter paper thoroughly, transfer the filter paper and contents to ashing dish, dry

0and ignite in muffle furnace at 550+25 C until the ash is white. Cool the dish, add the filtrate and evaporate to dryness on a water bath. Heat in muffle furnace again, cool in a desiccator and weigh as previously. Heat again in the muffle furnace for 1 hour, cool and weigh. Repeat these operations until the difference in mass between two successive weighing is less than 0.001 g. Record the lowest mass. Reserve the total ash for determination of acid insoluble ash. In case of nutmeg, mace, ginger and cloves the

0ignition should be carried out at 600+25 C. In case of ground mustard proceed as above and ignite for 1 hr after disappearance of carbon. Leach the ash with hot water, filter through ash less filter paper and wash filter paper thoroughly. Transfer the filter paper and contents to the dish, dry and ignite in muffle furnace again for 1 hour. Cool and add 5-10 drops of nitric acid evaporate to dryness on a water bath and heat in muffle furnace for 30 minutes. Repeat the addition of 5-10 drops of nitric acid, evaporating to dryness and heating in muffle furnace for 30 minutes. Cool and weigh.

6) Determination of ash insoluble in dil. HCL: To the dish containing total ash add 25 ml of dilute HCl and boil covering the dish with a watch glass to prevent spattering. Allow to cool and filter the contents of the dish through an ash less filter paper (medium fine). Wash the filter paper with hot water until the washings are free from HCl as tested by silver nitrate solution, and return it to the dish. Evaporate carefully on a water bath and

0ignite in a muffle furnace at 550+25 C for 1 hour. Cool the dish in a desiccator and weigh. Repeat the ignition for 1 hr, cooling and weighing till the difference in weight between two successive weighing is less than 0.001 g. Note the lowest weight.

7) Determination of cold water soluble extract: Weigh to the nearest 0.001 g about 2 g sample, transfer to a 100 ml volumetric flask, add distilled water and make up to mark. Stopper the flask and shake at approx 30 minutes interval, for 8 hours and allow to stand for 16 hours longer without shaking. Filter the extract through a dry filter paper, evaporate a 50 ml aliquot portion to dryness in the dish on the water bath and heat in an

0air oven at 103+2 C to constant mass, that is until two consecutive weighings separated by a period of 1 hour in the oven do not differ by more than 0.001 g. Record the lowest weight.

225

8) Determination of alcohol soluble extract: Weigh accurately about 2 g of test sample and transfer to a 100 ml volumetric flask and fill to mark with ethanol. Stopper the flask and shake at approximately 30 minutes interval for 4 hours and allow to stand 16 hours longer without shaking. Filter the extract through a dry filter paper, evaporate a 50 ml

0aliquot portion to dryness on a water bath and heat in oven at 103+2 C to constant mass, that is until two consecutive weighings separated by a period of 1 hour in the oven do not differ by more than 0.001 g. Record the final weight.

9) Determination of non volatile ether extract: Extract 2 g of ground sample in a Soxhlet apparatus with diethyl ether for 18 hours. Remove the ether by distillation followed by blowing with a stream of air with the flask on a boiling water bath and dry in

0an oven at 110+1 C till the loss in weight between two successive weighings is less than 2 mg. Shake the residue with 2-3 ml of diethyl ether at room temperature, allow to settle and decant the ether. Repeat the extraction until no more of the residue dissolves. Dry the flask again until the loss in mass between two successive weighing is less than 2 mg. Record the lowest weight.

10) Determination of volatile oil: The determination of volatile oil in a spice is made by distilling the spice with water, collecting the distillate in a graduated tube in which the aqueous portion of the distillate is automatically separated and returned to the distilling flask, and measuring the volume of the oil. The content of volatile oil is expressed as a percentage v/w.

11) Determination of crude fibre: Weigh accurately about 2-2.5 g ground sample into a thimble and extract for about 1 hour with petroleum ether in a Soxhlet extractor. Transfer the material in the thimble to a 1 litre flask. Take 200 ml of dilute sulphuric acid in a beaker and bring it to boil. Transfer the whole of the boiling acid to the flask containing fat free material and immediately connect the flask to a water cooled reflux condenser and heat so that the contents of the flask begin to boil within 1 minute. Rotate the flask frequently, taking care to keep the material from remaining on the sides of the flask and out of contact with the acid. Continue boiling for exactly 30 minutes. Remove the flask and filter through fine linen or through a coarse acid washed, hardened filter paper held in a funnel and wash with boiling water until the washings are no longer acidic to litmus paper. Bring some quantity of sodium hydroxide solution to boil under a reflux condenser. Transfer the residue on the filter into the flask with 200 ml of boiling sodium hydroxide solution. Immediately connect the flask with the reflux condenser and boil for exactly 30 minutes. Remove the flask and immediately filter through the linen or filter paper. Thoroughly wash the residue with hot water and transfer to a gooch crucible prepared with a thin but compact layer of asbestos. Wash the residue thoroughly first with hot water and then with about 15 ml of ethanol and with 3 successive washings of

0petroleum ether. Dry the gooch crucible and contents in an air oven at 105+1 C for 3 hours. Cool and weigh. Repeat the process of drying for 30 minutes, cooling and weighing until the difference between two consecutive weighings is less than 1 mg.

0Incinerate the contents of the gooch in a muffle furnace at 550+20 C until all carbonaceous matter is burnt. Cool the gooch crucible in a dessicator and weigh.

226

12) Quality analysis in turmeric: i) Determination of curcumin content: Grind sample as quickly as possible in a grinding mill to pass sieve with 1 mm diameter aperture. Weigh accurately about 0.1 g, add 30 ml alcohol and reflux for two and half hour. Cool the extract and filter quantitatively into a 100 ml volumetric flask Transfer the extracted residue to the filter. Wash thoroughly and dilute to mark with alcohol. Pipette 20 ml of the filtered extract into a 250 ml volumetric flask and dilute to volume with alcohol. Measure the absorbance of the extract and the standard solution at 425 nm in 1 cm cell against an alcohol blank.

ii) Determination of starch content: Extract about 3 g of the ground sample accurately weighed with five 10 ml portions of ether on a filter paper that will retain completely the smallest starch granules. Evaporate the ether from the residue and wash with 150 ml of 10 % ethyl alcohol. Carefully wash off the residue from the filter paper with 200 ml of cold water. Heat the undissolved residue with 200 ml of 2.5 % dil. HCl in a flask equipped with reflux condenser for two and half hour. Cool and neutralize with sodium carbonate solution and transfer quantitatively to a 250 ml volumetric flask and make up to volume. Determine reducing sugars in the solution by Lane and Eynon Volumetric

method.

iii) Test for presence of chromate: Ash about 2 g of the ground sample. Dissolve the ash in 4-5 ml of dilute sulphuric acid in a test tube and add 1 ml of diphenyl carbazide solution. The development of a violet colour indicates the presence of chromate.

References:

Anonymous 2005. Manual of Methods of Analysis of Foods (Spices and Condiments). Directorate General of Health Services, Min. of Health and Family Welfare, GOI, New Delhi.

A.O.A.C. 2000. XVII Edn. Official Method. Methods of Test for Spices and Condiments.

I.C.M.R. 1990. Manual Methods of Analysis for Adulterants and Contaminants in Foods.

227

Recent Techniques in Postharvest Management & Processing of Vegetables

PC Sharma, Manisha Kaushal and Anil Gupta

Department of Food Science & TechnologyDr YS Parmar University of Horticulture and Forestry, Nauni, Solan, HP

Introduction

Fruits and vegetables is one of the most important and fast growing sub-sectors as they form an indispensable part of healthy diet. World production of vegetables amounts to 486 million tons, while that of fruits is 392 million tons. India produces 71.0 million tons of fruits from an area of 5.8 million hectare and 133.4 million tons of vegetables from an area of 7.98 million hectare annually (NHB, 2010). Productivity of vegetables in India presently is 16.7 tons per hectare. India produces 36 % green peas and 10% onion of world's production. Onion, potatoes and green vegetables like okra, bitter gourd and green chillies also have good export potential. Being rich in vitamins, minerals, dietary fibre and natural antioxidants most vegetables are classified as the protective foods. However, owing to the presence of high moisture content and mostly being non acidic, the vegetables are highly perishable and needs to be handled properly and immediately after harvest. Processing of vegetables into different value added products is one of the most effective alternatives to reduce postharvest losses.

Postharvest losses

Fruits and vegetables are the reservoir of vital nutrients but being highly perishable, 25-33% of the total production of fruits and vegetables goes waste from the time of harvesting till they reach the consumers. Indian postharvest losses of fruits and vegetables are equivalent to the annual consumption of fruits and vegetables in U.K. In order to ensure minimum losses, proper postharvest handling and processing in to value added products are the two main alternatives.

Postharvest techniques used for value addition

In order to make horticulture a viable enterprise, value addition is essential. Harvest indices, grading, packaging, storage techniques have been developed/ standardized for major horticultural crops. Value addition through dehydration of vegetables including freeze drying, intermediate moisture foods, beverages etc are getting popular day by day. The general practices used for value addition are:

1. Preservation with salt: This method is usually used for preserving green beans, cauliflower, carrot, turnip and other vegetables in salt where the vegetables can be used during lean period especially in pickles etc (semi finished products).

2. Drying: Vegetables are dried after pre-treatments to be used in lean periods or in soup mixes. The pre-treatments include sorting, washing, slicing/cutting/depodding, blanching and sulphuring /sulphating prior to drying. The most applicable method of drying includes Solar drier, Poly-tunnel drier, Cabinet drying, Vacuum drying, Fluidized bed drying, Freeze drying, Microwave drying and combination of drying techniques.

3. Heat treatments: Vegetables can be preserved by heat processing (using canning or bottling). Spinach, lettuce, celery, asparagus, potato, peas etc are commercially canned. Vegetables are usually canned in brine solution (2-3%) containing 0.3% citric acid. After exhausting and sealing, the cans are

oprocessed in a pressure sterilizer at 115.5-121.1 C in order to destroy the spores of most resistant organisms. Vegetables can also be canned in tomato juice to replace the use of brine.

4. Freezing: It is another technique commercially used for preservation of vegetables mainly peas, pre-cut vegetables and mushroom. Approximate storage life of some frozen vegetables at various temperatures varies considerably. Beans, broccoli, cauliflower, peas and spinach have a storage

o olife of 6 to 8 months at -12 C while at -18 C the storage life varies from 14-16 months.

R&D in PHT of vegetable crops

Few R&D efforts made in different aspects of post harvest management & processing of vegetables in some institutes in the country include the following:

1. Varietal improvement: Success has been made in selection of Carrot and tomato cultivars with comparatively high carotenoid and vitamin A content .Onion and tomato cultivars with high TSS and longer shelf-life. Potato cultivars with low sugars and ginger with less fibre etc.

2. Pre-harvest treatments: The use of maleic hydrazide (1500-2500 ppm) 2-4 weeks before harvest for control of sprouting in onion during storage is effective (NRC O&G, Nasik).

3. Method of Harvesting: Most vegetables in India are harvested by hand. However, commodities meant for processing like tomatoes and potatoes can be mechanically harvested. Harvesters of different sizes with respect to economic feasibility and affordability of farmers are required to be developed in view of difficult hilly terrains in most of the fruit growing areas.

4. Market Preparation: Mechanical grader for onion having capacity of 1.5-2 ton/h developed at NRC O & G, Nasik is a significant development.

5. Post-harvest treatment: Postharvest treatment to delay yellowing in bitter gourd (IIHR, Bangalore) and gamma radiation (60-90 Gy) of cured onions within one month of harvesting to check sprouting during storage (NRC O & G, Nasik).

229

6. Primary processing: The available equipment and technologies for various unit operations of primary processing include farm level fruit and vegetable washing machine (PAU, Ludhiana), basket centrifuge, minimal processing technology of vegetable, shrink packaging of fruit and vegetable and hydro cooler-cum-washer for fruits and vegetables (CIPHET, Ludhiana), vegetable dryer (CIAE, Bhopal), mechanical fruit washer (MPKV, Kolhapur), tamarind dehuller and deseeder (UAS, Bangalore),cumin cleaner-cum-grader (Junagarh), turmeric washing and polishing machine (PAU, Ludhiana) and large scale chilly drying facility (ANGRAU, Baptala) etc. are some of the major developments.

7. Drying: - Different types of driers developed at various research institutes include:- Polytunnel solar drier for fruits and vegetables (YSPUHF, Solan), Solar cabinet drier for vegetables (CIAE, Bhopal), solar tunnel dryer for plantation crops (CPCRI, Kasargod), multipurpose polyhouse solar dryer for chilli (ANGRAU, Baptla), recirculatory solar drier for red chillies (MPKV, Kolhapur), process for dehydration of okra, pumpkin, French bean, ready to eat dehydrated carrot shreds (IIVR, Varanasi).

8. Value addition:- Few R&D efforts made in value addition of vegetables include Mushroom based instant noodles and soup powder (AICRP on PHT, Solan), beet root powder, carrot powder, chilli processing plant, green chilli powder and puree, dried garlic slices and ginger powder (CIPHET, Ludhiana), tomato paste and fluidized bed drier for mushroom (TNAU, Coimbatore) .

Recent innovations in vegetable processing

a) Modified Atmosphere Packaging Technology: Modified Atmosphere Packaging has been used to extend shelf-life in okra for 9 days, 7-8 days for broccoli and 25 days for capsicum in ambient temperature and 46 days in cold store. Shrink wrapping is one of the methods used for modifying the atmosphere of the commodity.

b) Individual Quick Freezing: Quick freezing is the process in which virtually all the properties of most foodstuffs are preserved. It involves ultra-rapid freezing of a food commodity to very low temperatures (-30°C to - 40°C) which halts the activities of the microorganisms that cause decay and deterioration. In IQF, each piece is frozen individually using technique of fluidization which results in freezing of vegetables within 10 to 12 minutes in contrast to 3 to 4 hours or even more taken in the blast freezer. This results into better texture and there is no lump/ block formation and the product is free flowing. The different steps involved in IQF are washing followed by depodding/peeling, inspection/sorting and blanching followed

o oby chilling (5-7 C) and quick freezing (-18 C) and finally packing in bulk or consumer packs.

230

c) Minimal Processing: Minimal processing is used to retain the natural and as-fresh properties of foods. Raw vegetables that are washed peeled, sliced, chopped or shredded into 100% usable product. They are then bagged or packaged to offer consumers high nutrition, convenience, and flavour while still maintaining its freshness. The microbiological, sensory and nutritional shelf life of minimally processed vegetables, inflorescence, root and stem tissues vary from 15-20 days.

Unit Operations in Fresh-Cut Produce (Minimally Processing) preparation involves:

·Receiving raw material: the raw material is kept under refrigeration o(1-5 C) until used.

·Cleaning and disinfection: vegetables are cleaned by washing, scrubbing and dipping in solutions of disinfectant.

·Pretreatments (Peeling, Trimming, Deseeding, Coring and Cutting)

·Washing and Cooling: Chlorinated water 50-100 ppm is used for washing. Cutting tools should be properly sanitized as these are the main source for contamination.

·Dipping: Produce can be optionally dipped in a solution of an acidulant /antioxidant. (blend consisting of a combination of ascorbic acid/citric acid e.g. anti-softening agent like calcium chloride)

·Drying to remove surface moisture: Different methods used for removal of excess water from fresh cut vegetables are conveyor shakers to remove water through a mesh; Air drying on conveyors with forced air to blow excess water off the surface of the produce; and basket centrifuge.

·Packaging: Produce can be packaged in modified atmosphere packages. In MAP, modified atmosphere can be created passively by using properly permeable packaging material or actively by using a specified gas mixture together with permeable packaging materials.

o·Storage and distribution: Storage at 10 C or above allows most

bacterial pathogens to grow rapidly on fresh cut vegetables. Therefore, transport and storage of produce should preferably be

ocarried out at 2-4 C

d) Value addition

i. Green chilli powder and puree: A process has been standardized for making green chillies powder and puree. About 130 g of green chillies powder and 300 ml puree could be prepared from one kilogram of fresh green chillies. Fresh chillies cost Rs. 15/kg while the cost of green powder (100g dry weight) is Rs. 120/kg.

231

ii. Canned vegetables: Generally vegetables are canned in 2-3% brine solution. In order to improve quality the brine solution can be replaced with concentrated tomato juice (8%) for canning of vegetables. Recipe for canning of mixed vegetables in tomato juice include Brinjal /eggplant (slices) 20%; peppers (cut) 20%; carrots (slices) 15%; green peas 5%; green beans (pods) 18%; okra (whole) 8% and tomatoes (whole or halves) 14%.

iii. Ginger: Ginger can be processed into dried ginger/ ginger slices (Sonth), ginger powder, ginger oleoresin (Aroma & pungency) and ginger oil (Aroma). Ginger drying involves following steps:

Fresh ginger

Washing

Soaking ginger overnight

Peeling

Whole pieces

Slicing

Lime treatment (2% Ca(OH)2

for 6 hours)

Lime treatment (2% Ca(OH)2

for 6 hours)

Sulphuring (3 g/kg for 4 hrs)

Sulphuring (3 g/kg for 4 hrs)

Drying (55+2oC) Drying (55+2

oC)

Dried ginger (sonth) 10-12% Dried ginger slices,

10-12%

Packing & storage

Grinding

Ginger powder

Packing & storage

232

Flow sheet for drying of ginger into sonth and powder

i. Bell pepper: Recipe has been standardized for the preparation of red coloured bell pepper pickle and chutney. The standardized recipe for preparation of chutney consists of bell pepper pulp (1Kg), sugar750g and acetic acid 10 ml with weighed amount of spices and salt.

ii. Potato: Detailed study has been conducted in the department to evaluate different varieties of potatoes can be processed into chips , French fries, potato starch and flour. Ready- to-serve tikki powder and halwa powder can be prepared from potato flour while custard powder is made from potato starch.

iii. Pumpkin: For the preparation of pumpkin candy, pickle and chutney the pumpkins are pretreated by steam blanching for 4 minutes + 1.5 per cent citric acid dip for 20 minutes. The chutney prepared from pumpkin shreds (100 per cent) was found to be the best in comparison to other combinations with apple (30:70, 40:60, 50:50) which reflected that ripe pumpkin can be used for production of good quality chutney. Similarly, pumpkin jam can be prepared by using pumpkin and apple pulp (30:70).

iv. Utilization of carrot pomace: After carrot juice extraction, up to 40-42% carotenoids are still left within carrot pomace. Steam blanching is a prerequisite for drying and storage of pomace for product development. For dehydration of carrot pomace, steam blanching (3 minutes) + 2000 ppm KMS treatment was standardized. Following products can be prepared by using dried carrot pomace.

a) Carrot pomace powder spread: For preparation of pomace spread, the standardized recipe contained different ingredients viz., carrot pomace powder (20 g), sugar (78 g), pectin (1.5 g) and citric acid (0.5 g).

b) Instant carrot pomace spiced beverage: The standardized recipe consists of carrot pomace powder (2.8 g), sugar (4.5 g), salt (1.1 g), black salt (0.3 g), mint powder (0.3 g), ginger powder (0.3 g), black pepper powder (0.1 g), cumin powder (0.1 g), red chilli powder (0.1 g) and citric acid (0.4 g) for preparation of instant carrot pomace spiced beverage.

c) Instant carrot pomace gazrella mix: The recipe containing dried carrot pomace shreds (12 g), sugar (30 g), skim milk powder (18 g), dried fruits (7 g), cardamom powder (0.6 g) and Desi ghee (10.5 g) has been optimized.

d) Carrot pomace pickle: The recipe containing rehydrated carrot shreds (225 g), jaggery (30 g), salt (12 g), ginger paste (10 g), garlic paste (10 g),

233

turmeric powder (2 g), red chilli powder (2 g), black pepper powder (1 g), cumin powder (1 g), large cardamom powder (0.8 g), fenugreek seed powder (0.4 g), mustard oil (65 ml), acetic acid (2 ml), sodium benzoate rated best for carrot pomace pickle.

Conclusion: The present information concludes the suitability of utilizing vegetables for the preparation of processed products having fairly good nutritional and sensory qualities. It will not only add to the diversified products but will also provide remunerative returns to the growers. Reduction of post-harvest losses also reduces the cost of production, trade and distribution, lowers the price for the consumer and increases the farmer's income.

234

SN Name and designation Address for correspondence

E.mail address Contact number

1. Dr. Satya Vart DwivediSMS/ Assistant Professor

Krishi Vigyan Kendra(Soubhadra) At: Crop Research Station Tissuhi, MarihanMirjapur-231 310 (U.P)

satyakvk@gmail.com 9415720119 (M)

2. Dr. R. Balakumarbahan

Assistant Professor (Hort.)

Horticultural Research Station

Tamil Nadu Agricultural University

Pechiparai-

629 161

Kanyakumari District

Tamil Nadu

hortibala@gmail.com

09688427067 (M) 04651 281191

3. Dr. Jagtap Venkat Sambhaji

Assistant Professor

Associate Dean and Principal college of Agriculture, Near Kini Osmanabad

Maharashtra

vsjagtap66@rediffmail.com

Fax.02472 2223249422657460 (M)

4. Dr.(Mrs.) Ekta Prashant Ningot

Assistant Professor

College of Agriculture

Soanpur,Gadchiroli,

Mul Road Near Complex Area, Soanpur

Gadchiroli, Maharashtra

442065

ekta248@rediffmail.com

Fax 07132 223062

07132 223061(O)

99229 11896 (M)

5. Dr. Neha Kiran Chopde

Assistant Professor Horticulture Section

College of Agriculture

Nagpur (M.S)

chopdeneha@yahoo.com

09922960826Fax 0712 2554820

6. Dr. Mrigendra Singh

Programme Coordinator Krishi Vigyan Kendra Shahdol Kalyanpur P.O Bhui Bandh Dist. Shahdol M.P

484 001

kvkshahdol@ rediffmail.com

07652 24179094251 83232Fax 07652 24179007652 241948

7. Dr. Shekhar Singh Baghal Assistant Professor/

Scientist

Department of soil Science and Agriculture Chemistry

College of Agriculture

JNKVV

Jabalpur (M.P)

482004

ssbatic@rediffmail.com ssbatic@gmail.com

09425888646 (M)

8. Dr. K.S Yadav

Programme Coordinator

Krishi Vigyan Kendra

Bahmori Farm, P.O Rajaua

Sagar, M.P, 470 002

kvksagar@rediffmail.com

ksyadav20@rediffmail.com

Fax 07582 248290Ph.07582 28822994258 54876

9. Dr. Yashpal Singh

Assistant Professor

College of Agriculture

JNKVV, M.P

guruyash@yahoo.com

09425341853

10. Dr. Patel Popatlal Jesangidas

Assistant Research Scientist

Main-Castor

Mustard Research Station

S.D Agricultural University

Sardarkrushinagar

385506 Dist. Banaskantha

Gujarat

dpatel.norta@gmail.com

pjpatel31@rediffmail.com

02748 27845709979 786074Fax 02748 278433

11. Dr. Patel Devendra Kantilal

Assistant Research Scientist

Main-Castor

Mustard Research Station

S.D Agricultural University

Sardarkrushinagar

385506 Dist. Banaskantha Gujarat

devendrakumar1996@gmail.com

02748 278457

09879848765 (M)Fax 02748 278433

12. Dr. Ramjibhai Narsinhbhai PatelAssistant Research Scientist

Seed TechnologyS.D Agricultural University

Sardarkrusninagar385506, Dist. BanaskanthaGujarat

visitrnpatel@gmail.com 0992585823402748278433

List of Participants

i

13. Dr. Dhirajlal Limbabhai Varmoda Assistant Research Scientist

Fruit Research Stationm, J.A.U Amrutbagh, Mangrol 362225, Gujarat

dlvarmoda@gmail.com

02878-222127094284 40031 (M)

14. Dr. Naveen Garg Assistant Vegetable Botanist

Punjab Agricultural University

Regional Research Station, Bathinda 151001

Punjab

garg1202naveen@yahoo.co.in

naveen@pau.edu

0164 2212159094170 84075 (M)Fax 0164 2212159

15. Dr. Gurdarshan Singh

Assistant Professor

Krishi Vigyan Kendra

Faridkot-

151203

Punjab

singhgurdarshan77@gmail.com

98769-62786

16. Dr. Faizan Ahmad

SMS (Hort.)

Krishi Vigyan Kendra, Kargil, Sher-E-

Kashmir

University of Agriculture Science & Technology of Kashmir, Shalimar Srinagar

(J&K)

faiz_an@rediffmail.com

01985-233585

9419218019 (M)Fax

01985 233585

17. Dr. Vikas Abrol

Jr. Scientist

DLRSS, Dhiansar

181133, SKUAST-J, J&K

abrolvics@gmail.com

01923 22082109419135634Fax 01923 220821

18. Dr. Partha Choudhuri

Lecturer

Department of Vegetable and Spice Crops

Faculty of Horticulture

Uttar Banga Krishi Viswavidyalaya

P.O Pundibari

Dist. Cooch Behar

West Bengal

-736165

Partha2909@rediffmail.com

03582 27058609474 19827Fax

03582270586

19. Mr. Partha Sarathi

Medda

Lecturer (Sr. Scale)

Department of Plantation Crops and Processing

Faculty of horticulture

UBKV Pundibari, Coochbehar

West Bengal

psmedda@gmail.com

03582 22891109474567593Fax 03882270586

20. Dr. Pankaj Mittal

SMS (Vegetables)

Krishi Vigyan Kendra Dhaulakuan

Distt. Sirmour, (H.P)

pankajmittalpau@gmail.com

94184-5762398056 62119 (M)Fax 01704257462

21. Dr. Manoj Gupta

Extension Specialist

(Agril

Economics)

Krishi Vigyan Kendra

Dhaulakuan

Distt. Sirmour (H.P)

173001

manojgupta@yahoo.co.in

941846820301792 222295 Fax017404 257462

22. Dr. Jagat Singh MalikDES (Veg. Science)

Krishi Vigyan KendraNear Dist. Court Ambala City, V.P.O Pauli Teh. & Dist. Jind, Haryana

malik.jagatsingh@gmail.co

099961 77652

23. Dr. Sangeeta ShreeJr. Scientist-cum-Assistant Professor

Department of HorticultureB.A.U, Sabou, 813210Bhagalpur, Bihar

sangeetashree@yahoo.in 09931240390

ii