View
221
Download
0
Category
Tags:
Preview:
Citation preview
Introduction
• Nursery weeds are unwanted plants in a nursery which reduce
availability of moisture, nutrients, sunlight and growing space to
the seedlings.
• Weeds reduce crop growth, quality and yield. They make uprooting
and transplanting difficult. Weeds also act as alternative hosts to
pests and diseases affecting nursery seedlings.
• Weeds are difficult to mange as they grow and produce enormous
and hardy reproductive structures like seeds.
• Integrated, combined and coordinated effort should be made in
order to manage weeds in a nursery. Weed control involves
cultural, mechanical and chemical methods of reducing weeds.
Effect of Weeds on Nursery
Weed population reduce crop yield by competing for water, light, soil
nutrients, and space. The combined effects of weeds are:
• Reduced seedling quality by contamination of weeds in nursery.
• Interference during uprooting and transplantation of seedlings.
• Serve as hosts for various crop pest and diseases.
• Production of chemical substances which are toxic to nursery
plants.
Characteristics of Nursery Weeds
Specific characteristics of weeds make them hardy and helps their long
survival under unfavorable conditions:
• Genetic ability to produce abundant seed s and propagating units.
• Long term seed dormancy, long term seed survival and wide spread distribution and establishing ability.
• Adaptation in wide ecological and climatic conditions for survival in unfavorable growing conditions.
There are nearly 300000 plant species on the earth, out of which nearly
3 % plants (9000 plants species) acts as weeds.
Weed Management in Tomato Nursery
• Tomato seedlings require regular and shallow hoeing during
their initial days in the field. The surface soil is loosened by
hand hoeing and weeds are removed by hand weeding.
• Mulching with straw or black polythene or many other
materials found beneficial in managing weeds, diseases and
improving the quality of seedlings produced.
• Proper preparation of land, sanitation, irrigation management,
balanced plant nutrient supply and crop rotation practices can
effectively reduce the weed population nursery.
Weeds in Tomato Nursery
Branched broomrape, (Orobanche ramosa)
Young dodder Cuscuta spp.Bermuda grass (Cynodon dactylon).
Common groundsel, Senecio vulgaris. Common purslane, Portulaca oleracea
Chemical Weed management in Tomato Nursery
Stages of Application Weedicide Dose Remarks
Preplanting surface application
AlachlorFluchloralinMetribuzinNitrofenOxadiazon
1.0-1.25 kg/ha1.25 kg/ha0.35 kg/ha1.0 kg/ha1.0 kg/ha
Applied before sowing seeds on the nursery beds.
Pre emergence (in direct seeded crop)
AlachlorMetribuzinBensulideDiphenamid
1-2 kg/ha0.2-0.35 kg/ha4-6 kg/ha4-6 kg/ha
Should not be used in glass houses and high pH soils. Also do not tank- mix fertilizers with it.
Post emergence Metribuzin 0.28-0.5 kg/ha Apply when the crop is in 4-6 leaf stage
Precautions while using Weedicides
Using chemical weedicides is a fast, effective, labor saving and
cheaper method of managing weeds in the tomato nursery.
However, weedicides must be used judiciously for profit
maximization. Following points must be considered during weedicide
use,
• Selection of proper weedicide based on application time and
method.
• Doses and method of application of weedicides as per
recommendations.
• Time and growth stages of crop considering environmental
conditions before application.
Recommended