Question

when weeds are identified in the early stages in their infestation, eradication is more likely. control is economical when carried out early, rather than waiting early until the weed infestation has spread and become establish. discuss the base/ basis of this recommendation?

Answer 1

Answer:

Weeds are probably the most ever-present class of crop pests and are responsible for marked

losses in crop yields. Of the total losses caused by pests, weeds have a major share (30%). They

reduce the crop yield and deteriorate the quality of produce and hence reduce the market value of

the turnout. Therefore, management of weeds in all agro-ecosystems is imperative to sustain our

crop productivity and to ensure the food security to the burgeoning population.

There has been a long-felt need for a teaching manual on Principles and Practices of Weed

Management. This manual is a precise account of various theoretical aspects of weed

management presented in a simple language suitable for Agron 503 students. The manual has

been divided in 5 units. The first unit covers classification and characteristics of weeds, special

weed problems including aquatic and parasitic weeds, ecology and physiology of major weeds

and ecophysiology of crop-weed competition including allelopathy. In the second unit principles

and methods of weed control, concept of integrated weed management, principles of chemical

weed control and weed control through bioherbicides are discussed. Third unit constitutes of

mode and mechanism of action of herbicides, herbicide selectivity, herbicide combinations,

adjuvants and safeners, degradation of herbicides in soils and plants, effect of herbicides in

relation to environment and herbicide resistance in weeds and crops. In the fourth unit weed

management in major crops and cropping systems, weed shifts in cropping systems and control

of weeds in non-cropped situations including grasslands, pastures, tea gardens, orchards and

aquatic ecosystem in hills are covered. The fourth unit included cost: benefit analysis of weed

management and weed indices.

With all these varied aspects covered in the manual, we hope this will fulfill the requirement of a

much needed standard document on Principles and Practice of Weed Management not only for

the students but also for the teachers, scientists and others involved the field of weed

management. The authors would welcome additional information and suggestions from students

and teachers to improve the manual

Explanation: