Grevit 200 sl in the protection and storage of greenhouse vegetables

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GREVIT 200 SL IN THE PROTECTION AND STORAGE OF GREENHOUSE VEGETABLES IN CONVENTIONAL, INTEGRATED AND ORGANIC PRODUCTION

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GREVIT 200 SL

IN THE PROTECTION AND STORAGEOF GREENHOUSE VEGETABLES

IN CONVENTIONAL, INTEGRATEDAND ORGANIC PRODUCTION

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GREVIT 200 SL

THE PROTECTION AND STORAGEOF GREENHOUSE VEGETABLES

IN CONVENTIONAL, INTEGRATEDAND ORGANIC PRODUCTION

Copyright © 2008 Avis Naturall Poland Ltd. All rights reserved.

POWEROF NATUREAT YOURSERVICE

POWEROF NATUREAT YOURSERVICE

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Poland’s membership of the European Union has enabled vegetable pro-ducers to increase production, most of which has been destined for export. However, in order to meet the requirements of foreign consumers, and more and more often also of those at home, Polish producers are forced to submit their produce to new quality control systems. This makes the producers give up using many chemical plant protection products. For that reason, the in-tegrated method of production is becoming more and more popular with vegetable growers. It allows them to obtain high yields of high quality pro-ducts. The method is based on minimizing the use of mineral fertilizers and chemical plant protection products while at the same time making full use of agrotechnical and technological elements. The integrated method requ-ires producers to possess a lot of professional knowledge in that area and is far more difficult that the conventional method. However, the producers who employ the integrated method of production are eligible to apply for a certificate for their products, which proves that the products are of high quality with respect to both their healthiness and nutritional value. The fact that in Poland many active substances have been withdrawn, and have not been replaced by new ones, thus creating a large gap in the range of plant protection methods, makes it necessary to search for new production-rela-ted solutions. One of the successful results of this search is Grevit 200 SL,a natural and completely safe product that gives good and effective solu-tions in the integrated production of greenhouse vegetables.

Grevit 200 SL is the first, unique solution in controlling bacterial and fun-gal diseases that acts on contact and can be used for both curative and preventive treatments. It also effectively supports the defence system of plants by helping to prevent infection hotspots from developing.

Grevit 200 SL does not require a waiting period or a prevention period, and does not persist in the treated plants, thus being completely safe for people, animals, beneficial insects and the environment. It can be used at any stage of both commercial and amateur production of vegetables. Grevit 200 SL makes it possible to use unique solutions recommended for pre- and post-harvest protection of root vegetables, brassica (cab-bage-like) vegetables and lettuce.

Grevit 200 SL has been authorized for use in ecological agriculture:Certificate No. BRŚOR-EKOL-001/2005 of 3 March 2005.

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The production of greenhouse vegetables begins with the preparation and conditioning of seeds by soaking them for a short period of time(2 minutes) in a 0.5% solution of Grevit 200 SL. In this way, the crops of greenhouse vegetables will be protected against decay diseases caused by a variety of pathogenic fungi and bacteria that may be carried by the seeds.

THE MOST COMMON DISEASES OF CUCUMBERPREVENTION AND CONTROL

GREY MOULD

SYMPTOMS – decay of stems and fruitlets. The affected areas are covered with a grey layer of fungus spores.CONTROL MEASURES – spray plants with Grevit 200 SL at a concentration of 0.1% (100 ml of the product in 100 litres of water) using 100–200 litres of working solution per 1000 m2. Treatments should be carried out every 10–14 days when outbreaks of the disease have occurred. If the disease poses a gre-at threat, spray as often as every 7 days.

ANGULAR LEAF SPOT OF CUCUMBER

SYMPTOMS – the disease occurs during periods of warm and humid weather. Angular lesions appear on leaves. The lesions are initially olive-yellow witha whitish bacterial ooze on the underside, later appearing as holes in the le-aves, especially in those in the early growth stage. These symptoms coincide with the first symptoms of downy mildew and it is difficult to distinguish the two diseases in field conditions.CONTROL MEASURES – growing mustard as a forecrop helps reduce the inci-dence of the disease. Spray the plants with Grevit 200 SL at a concentration of 0.1–0.2% (100–200 ml of the product in 100 litres of water) using 120–150 litres

of working solution per 1000 m2. Higher doses of the pro-duct should be used during periods of a greater risk of the di-sease to plants. Carry out 2–3 treatments in the vegetative season, every 7–10 days depending on the risk of the dise-ase.

Symptoms of angular leaf spot on cucumber leaves

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POWDERY MILDEW

SYMPTOMS – a thick white coating develops on leaves and stems, then the leaves and whole plants wither away. This occurs in the second half of sum-mer during periods of dry and warm weather with occasional showers.CONTROL MEASURES – as soon as the first symptoms appear, spray the plants with Grevit 200 SL at a concentration of 0.1–0.2% (100–200 ml of the product in 100 litres of water) using 120–150 litres of working solution per 1000 m2. Higher doses of the product should be used during periods of a greater risk of the disease to plants. Carry out 2–3 treatments in the vegeta-tive season, every 7–10 days depending on the risk of the disease to plants. Adding a wetting agent will increase the effectiveness of the treatments.

Symptomsof powdery mildewon cucumber leaves

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DOWNY MILDEW

SYMPTOMS – olive-yellowish lesions on leaves, confined between leaf ve-ins, gradually becoming brown, later drying up. A grey-purple coating can be seen on the underside of the leaves. Plants slowly wither away.CONTROL MEASURES – begin spraying the plants with Grevit 200 SL at the end of June every 7-10 days or according to indicators, at a concentra-tion of 0.1–0.2% (100–200 ml of the product in 100 litres of water) using120–150 litres of working solution per 1000 m2. Higher doses of the product should be used during periods of a greater risk of the disease to plants.In order to control downy mildew, the product should be used alternately with other fungicides that have a translaminar and systemic mode of action. When cucumber cultivars tolerant to downy mildew are grown, they can be protected by means of only Grevit 200 SL without the need to spray them alternately with other fungicides.

Symptomsof downy mildewon cucumber leaves

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THE MOST COMMON DISEASES OF TOMATOPREVENTION AND CONTROL

BACTERIAL SPECK OF TOMATO

SYMPTOMS – initially, small black specks with or without a yellow rim ap-pear, most often along the leaf veins or leaf edges. Similar symptoms occur in the later growth stages on stems, leaf shoots, flower buds and fruitlets. Necrotic, slightly raised, drying spots develop on the fruit.CONTROL MEASURES – begin spraying the plants with Grevit 200 SLas soon as the first symptoms of the disease appear. Carry out 2–3 treat-ments every 7–10 days at a concentration of 0.15% (150 ml of the product in 100 litres of water) using 120–150 litres of working solution per 1000 m2.If the risk of the disease is great, spray treatments should be applied already when seedlings are being produced and before planting, and should sub-sequently continue until fruit harvest. Larger volumes of water should be used for vigorously growing tomato cultivars or those grown with the aid of stakes.

Symptomsof bacterial speckon tomato

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POTATO BLIGHT (LATE BLIGHT OF POTATO/TOMATO)

SYMPTOMS – initially, green-brown, water-soaked lesions appear on le-aves. Leaf veins gradually turn black. The lower leaf surface becomes cove-red with a whitish layer of mycelium. Grey-brown lesions appear on stems and the stems break in these areas. On tomato fruit, slightly raised lesions appear that turn brown and develop a whitish coating of mycelium. CONTROL MEASURES – spray the plants with Grevit 200 SL as soon as the first symptoms of the disease appear, or according to indicators, 3–4 times every 6–7 days at a concentration of 0.15% (150 ml of the product in 100 li-tres of water) using 120–150 litres of working solution per 600–1000 m2. The product should be used alternately with other fungicides recommended for controlling potato blight in tomato. Larger volumes of water should be used for vigorously growing tomato cultivars or those grown with the aid of stakes.

Symptomsof potato blighton a tomato

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GREY MOULD

SYMPTOMS – grey, transparent lesions can be seen on leaves. Fruit buds and the fruit begin to decay at the heel end; stems and leaf stalks begin to wither away. The affected areas are covered with a grey coating.CONTROL MEASURES – begin spraying the plants with Grevit 200 SL during periods of a high risk of the disease, or when the first symptoms of the disease have appeared, 3–4 times every 6–7 days, at a concentrationof 0.15% (150 ml of the product in 100 litres of water) using 120–150 litres of working solution per 600–1000 m2.

POWDERY MILDEW

SYMPTOMS – grey, transparent lesions can be seen on leaves. Fruit buds and the fruit begin to decay at the heel end; stems and leaf stalks begin to wither away. The affected areas are covered with a grey coating.CONTROL MEASURES – begin spraying the plants with Grevit 200 SLas a preventive measure, or when the first symptoms of the disease have appeared, 3–4 times every 7–10 days, at a concentration of 0.15% (150 ml of the product in 100 litres of water) using 120–150 litres of working solution per 1000 m2.

Symptomsof grey mouldon a tomato

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BACTERIAL CANKER (DISINFECTION OF MINERAL WOOL MATS)

SYMPTOMS – groups of leaves begin to wither away; a cross-section of the stem shows zones of vascular bundles that have turned brown; the cortex comes away from the vascular cylinder of the stem. Raised, necrotic spots of cracked skin are visible on the stem. On tomato fruits, the reticulate structure can be seen under their skin. In the last stage, so-called “bird’s eyes” appear on the fruit. Bacterial canker is a quarantine disease and each occurrence must be reported immediately to the Plant Protection and Seed Production Inspectorate, which determines the means of eliminating the hotspots of infection.CONTROL MEASURES – Grevit 200 SL is recommended for disinfecting mats to protect tomato plants against bacterial canker. It is used at concen-trations of 0.05 or 0.1% (50–100 ml of the product in 100 litres of water). The recommended dose is 15 ml of the solution per mat (for full saturation), with mats to be soaked for 24 hours. Higher doses of the product should be used if there is an increased risk of bacterial canker occurring on a given farm. The product has greater effectiveness than standard chemical disinfectants.

Means of disinfecting mineral wool

Product concentra-

tion %

Average degree of discoloration of vascular bundles on a scale 0 – 50

% of plants withinternal symptoms

GREVIT 200 SLGREVIT 200 SL

Desogerme SP standard

Control

0.050.1

0.15

–

0.5 a0.2 a

1.3 b

1.5 b

33 b17 a

50 c

67 dThe effectiveness of the product GREVIT 200 SL in the disinfection of mineral wool against bacterial canker (Clavibactermichiganensis ssp. michiganensis) SKIERNIEWICE 2004

Symptomsof bacterial cankeron a tomato stem

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THE MOST COMMON DISEASES OF LETTUCEPREVENTION AND CONTROL

Caution: For lettuce grown in the field or under cover, the concentration of Grevit 200 SL should not exceed 0.1% (100 ml of the product in 100 litres of water).

GREY MOULD

SYMPTOMS – grey, transparent lesions can be seen on leaves. Fruit buds and the fruit begin to decay at the heel end; stems and leaf stalks begin to wither away. The affected areas are covered with a grey coating.CONTROL MEASURES – spray the plants with Grevit 200 SL at 7-day inte-rvals, with the first treatment applied when seedlings are being produced, and the subsequent 1–2 spray treatments after planting them in a permanent area, at a rate of 0.1% (100 ml of the product in 100 litres of water) using 70–80 litres of working solution per 1000 m2. A smaller volume of the solution sho-uld be used for plants in the early stages of development. The product should be used alternately with fungicides designed for controlling grey mould in lettuce. Lower planting density reduces the incidence of the disease.

BACTERIAL SOFT ROT, SLIMY ROT OF LETTUCE HEART LEAVES

SYMPTOMS – small, brown lesions surrounded by a yellowish border can be seen on leaves. The lesions gradually become bigger and adopt angular shape delimited by the veins.Slimy rot of lettuce heart leaves is caused by bacteria of the genus Erwinia. It also results in the decay of lettuce heads at the base.CONTROL MEASURES – spray the plants with Grevit 200 SL as a preventive measure during periods of the indicated risk of the disease, once or twice every 7–10 days, or at 7-day intervals. Apply the first treatment when se-edlings are being produced, and the subsequent 1–2 treatments after they have been planted in a permanent area, at a concentration of 0.1% (100 ml of the product in 100 litres of water) using 70–80 litres of working solution per 1000 m2 when lettuce is grown under cover. A smaller volume of the solution should be used for plants in the early stages of development. The diseases are favoured by abundant watering, particularly during periods of temperatures above 200C.

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WHITE MOULD OF LETTUCE

SYMPTOMS – the infected area is covered with a thick white woolly coating; inside the white mycelium you can see black sclerotia – fungus reproducti-ve structures.CONTROL MEASURES – spray the plants with Grevit 200 SL as a preven-tive measure, or when the first symptoms of the disease have appeared,2–3 times every 7–10 days, at a concentration of 0.1% (100 ml of the product in 100 litres of water) using 70–80 litres of working solution per 1000 m2 when lettuce is grown under cover. A smaller volume of the solution should be used for plants in the early stages of development.

DOWNY MILDEW

SYMPTOMS – olive-yellow lesions, gradually becoming darker, appear on the upper leaf surface. Within them, but on the lower leaf surface, a thick grey-white coating of conidial spores can be seen.CONTROL MEASURES – spray the plants with Grevit 200 SL as a preventive measure every 7-10 days after planting and when there is a risk of the disease (especially when lettuce is grown in autumn), or when the first symptoms of the disease have appeared, 2–3 times every 7–10 days, at a concentration of 0.1% (100 ml of the product in 100 litres of water) using 70–80 litres of working solution per 1000 m2 when lettuce is grown under cover. A smaller volume of the solution should be used for plants in the early stages of de-velopment. Only those lettuce cultivars that are resistant to downy mildew should be grown. Do not grow lettuce at too high a planting density.

Symptomsof downy mildewon lettuce

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POWDERY MILDEW

SYMPTOMS – a white floury coating appears on the upper and lower leaf surfaces, which forms a cover inhibiting assimilation. The affected leaves gradually wither away.CONTROL MEASURES – spray the plants with Grevit 200 SL as a preventive measure 2–3 times at 7-day intervals, or 2–3 times every 7–10 days when the first symptoms of the disease have appeared, at a concentration of 0.1% (100 ml of the product in 100 litres of water) using 70–80 litres of working solution per 1000 m2. A smaller volume of the solution should be used for plants in the early stages of development. Grow only those lettuce cultivars that are resistant to downy mildew. Do not plant lettuce too densely.

Symptomsof powdery mildewon lettuce

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NECROTIC SPOTTING OF LETTUCE LEAVES (ANTHRACNOSE)

SYMPTOMS – at first, small water-soaked lesions become visible. They gra-dually turn brown and the tissue dries out. As a result, small irregular holes develop in the leaves.CONTROL MEASURES – spray the plants with Grevit 200 SL at a concentra-tion of 0.1% (100 ml of the product in 100 litres of water) using 70–80 litres of working solution per 1000 m2, 2–3 times in the vegetative season, with the first treatment applied 4–7 days after planting and later at 10–14-day intervals for lettuce grown under cover. Do not plant lettuce too closely together.

DAMPING-OFF (PYTHIUM) AND PHYTOPHTHOROSIS

SYMPTOMS – plants turn yellow and the part below the leaves darkens and narrows down. The plants begin to wilt, bend over and die. The disease is favoured by a soil substrate that is too damp and cold.CONTROL MEASURES – water the seedlings with Grevit 200 SL at a con-centration of 0.1% (100 ml of the product in 100 litres of water) using 100 ml of working solution per plant.

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GREY MOULD AND BACTERIAL SOFT ROT(PRE- AND POST-HARVEST PROTECTION OF LETTUCE)

SYMPTOMS – decay of leaves takes place. The affected areas are covered with a grey layer of fungus spores.CONTROL MEASURES – Grevit 200 SL is an exceptional and completely safe natural product for post-harvest protection of head lettuce. It is spray-ed at a concentration of 0.1% (100 ml of the product in 100 l of water) on lettuce heads immediately after harvest. For pre-harvest protection of head lettuce, Grevit 200 SL is used at the same concentration of 0.1% (100 ml of the product in 100 l of water) immediately before harvest to protect against grey mould and bacterial soft rot occurring during short periods of storage. The product is used immediately after harvest by dipping lettuce heads for 2–3 seconds in the amount of solution sufficient for completely submer-ging the heads. After the heads have been dried, they should be placed in unit packages, in a single layer covered with a thin foil. Lettuce should be kept at 0oC for a period of up to 30 days.

Symptoms of grey mould on lettuce in a storehouse. On the right are heads treated in a post-harvest bath of Grevit 200 SL solution.

Photo of an experiment carried out at the Institute of Vegetable Crops in Skierniewice.

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THE MOST COMMON DISEASES OF AUBERGINEPREVENTION AND CONTROL

The production of aubergine begins with the preparation and conditioning of seeds by soaking them for a short period of time (2 minutes) in a 0.5% so-lution of Grevit 200 SL. In this way, the crop will be protected against decay diseases caused by a variety of pathogenic fungi and bacteria that may be carried by the seeds.

Grafting on the resistant KVFN rootstock protects aubergine plants against verticillium wilt, to which aubergine is particularly susceptible.

GREY MOULD

SYMPTOMS – fruitlets decay and drop off; the affected areas are covered with a grey layer of wintering mycelium. The disease occurs mainly in den-sely spaced aubergine plants growing at high humidity, especially under plastic cover.CONTROL MEASURES – Grevit 200 SL is the first fully effective and safe natural product in Poland for the protection of aubergine against grey mo-uld on crops grown under cover. It is recommended to be used as a pre-ventive measure and sprayed at a concentration of 0.15% (15 ml in 100 lof water), 2–3 times every 10–14 days, alternately with fungicides prescribed in the protection programme. Volume of working solution required: 40 l per 1000 m2 of crop surface area.

THE MOST COMMON DISEASES OF PEPPERPREVENTION AND CONTROL

In the production of pepper, chemical or thermal disinfection of the soil substrate should be regarded as an essential treatment in the fight against verticillium wilt, fusariosis, suberized roots and root-knot nematodes be-cause there are no cultivars resistant to these soil pathogens.

The production of pepper begins with the preparation and conditioning of seeds by soaking them for a short period of time (2 minutes) in a 0.5% so-lution of Grevit 200 SL. In this way, the crop will be protected against decay diseases caused by a variety of pathogenic fungi and bacteria that may be carried by the seeds.

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GREY MOULD

SYMPTOMS – initially, wet transparent lesions appear on leaves. Then, fruit buds and the fruit begin to decay at the heel end; stems and leaf stalks be-gin to wither away. The affected areas are covered with a grey coating. Me-chanical damage to the leaves and stems, high humidity, low temperature and high planting density all favour the development of the disease.CONTROL MEASURES – spray the plants with Grevit 200 SL as a preventive measure, or immediately after the first symptoms of the disease have appe-ared, 2–3 times every 7–10 days in the vegetative period, at a concentration of 0.2% (200 ml of the product in 100 litres of water), alternately with the prescribed fungicides during periods that favour the development of the disease. Volume of working solution required: 100–120 litres per 1000 m2.

BACTERIAL SOFT ROT OF FRUIT

SYMPTOMS – wet decay of fruit and stems changing into a slimy mass. The affected fruit resembles a water-filled bag. The liquid from the fruit has no odour. Primary infection may originate from the soil that gets onto the surfa-ce of the fruit during watering. During the vegetative period, the bacteria are again spread by insects and mechanical means used to cultivate the plants.CONTROL MEASURES – as a preventive measure, spray the plants withGrevit 200 SL, 2–3 times at 7–10-day intervals, at a concentration of 0.2% (200 ml in 100 l of water), alternately with the fungicide Amistar 250 SC.Volume of working solution required: 100–120 l per 1000 m2.

BACTERIOSIS OF PEPPER: BACTERIAL SPOT

SYMPTOMS – irregular, brown-black lesions with a yellow border appear on leaves. The lesions on the fruit have no border.CONTROL MEASURES – as a preventive measure, spray the plants with Gre-vit 200 SL 2–3 times at 7–10-day intervals, at a concentration of 0.2% (200 ml in 100 l of water), alternately with the fungicide Amistar 250 SC. Volume of working solution required: 100–120 l per 1000 m2.

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ALTERNARIOSIS OF PEPPER, ANTHRACNOSE OF PEPPER AND OTHER FUNGAL DISEASES

SYMPTOMS – sunken circular lesions covered with a black velvety layer of fungus appear on fruit.CONTROL MEASURES – spray the plants with Grevit 200 SL as a preven-tive measure, or immediately after the first symptoms of the disease have appeared, 2–3 times every 7–10 days during the vegetative period, at a con-centration of 0.2% (200 ml of the product in 100 litres of water), alternately with fungicides from other chemical groups. It is advisable to use the pro-duct in a mixture with Amistar 250 SC. Volume of working solution required: 100–120 litres per 1000 m2.

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Grevit 200 sl in the protection and storage of greenhouse vegetables