ECONOMICAL EFFICACY OF DIURON AS A WEED CONTROL OPTION IN RAINFED COTTON

Abstract

Cotton, popularly known as “King of fibre†and “White gold†is the most important fibre and commercial crop of India. The contribution of India to global cotton fibre and edible oil production is 44 and 10%, respectively. Though India has the largest area (26%) of cotton in the world, due to its lower productivity the share to the total world cotton production is only 12%. Weeds consume 5 to 6 times of N, 5 to 12 times of P and 2 to 5 times of K more than cotton crop and thus reduced the cotton yield from 54 to 85% (Jain et al. 1981). Cotton is very sensitive to crop-weed competition due to slow growth during early stage and wider spacing. Weed infestation in cotton has been reported to offer severe competition causing yield reduction to an extent of 74 percent (Shelke and Bhosle, 1990), 50 to 85 percent (Sharma, 2008) depending upon the nature and intensity of weeds. The critical period of weed competition in cotton was found to be 15 to 60 days (Sharma, 2008). Weed management options
should prevent weed interference, be economical and sustainable, reduce weed seed bank in soil, prevent weed resistance and neither cause phytotoxicity to cotton nor reduce the cotton lint quality. Manual weeding
has traditionally been a labour intensive operation and hence there is no other alternative rather than use of post emergence herbicides for control of weeds in cotton. Herbicide is an economic alternative when labour is a problem or in abnormal weather situation where fields are not accessible for mechanical weeding.