Response of Cotton to Tillage and Post-Emergence Herbicides in Wheat-Cotton System in Pakistan

Conservation tillage with broad-spectrum herbicides may have the potential to control weeds and enhance cotton (Gossypium hirsutum L.) yield. Field experiment was conducted in 2010 and 2011 at Agriculture Research Institute, D.I. Khan, Pakistan to examine tillage and herbicide effects on weed control and cotton yield in wheat-cotton system. The experiment was arranged in split plot in RCBD with 4 replications. The main plot treatment comprised of three tillage systems, including zero (ZT), reduced (RT), and conventional tillage (CT), while the sub plot was weed control treatments namely, haloxyfop-R-methyl 10.8 EC (108 g a.i. ha(-1)), lactofen 24 EC (168 g a.i. ha(-1)), haloxyfop + lactofen, hand weeding, and weedy check. Broad-spectrum herbicides(haloxyfop + lactofen) reduced weeds by 92 and 94%, and produced highest lint-yield (1222 and 1515 kg ha(-1)) in 2010 and 2011, respectively. Relative weed-density was modified by tillage with lowest values recorded in CT. However, RT with broad-spectrum herbicides had the maximum weed reduction and lowest dry weed biomass (DWB). Reduced tillage with broad-spectrum herbicides produced maximum plant height, 100-seed weight, and lint yield. This combination is an optimum weed management strategy that contributes significantly to cotton production. However, if deep-rooted perennial weeds persist, CT with broad-spectrum herbicides may be occasionally required.