COMPARATIVE EFFICACY OF DIFFERENT POST-EMERGENCE HERBICIDES IN WHEAT (Triticum aestivum L.)

A field experiment was carried out to study the efficacy of different post-emergence herbicides for controlling weeds in wheat during a Rabi season 2008-09. Experiment comprised of six treatments, i.e. weed-infested control, pyroxasulfone at 50 g a.i ha^-1, metribuzin at 250 g a.i ha^-1, isoproturon at 1080 g a.i ha^-1, clodinafop propargyl at 240 g a.i ha^-1 and bromoxynil+MCPA at 247+247 g a.i ha^-1 as post-emergence herbicides. Results revealed that Post-emergence application of isoproturon (1080 g a.i ha^-1) proved to be best for obtaining maximum grain plus straw yield up to the level of weed-free control. Bromoxynil+MCPA (247+247 g a.i ha^-1) and clodinafop propargyl (240 g a.i ha^-1) also gave maximum spike bearing tillers, number of grains spike^-1 and 1000-grain weight. Isoproturon (1080 g a.i ha^-1) strictly reduced the weeds population as well as biomass as compared to weed-infested control. Poor weed control was achieved by using pyroxasulfone and metribuzin treatments. Hence, post-emergence Isoproturon (1080 g a.i ha^-1) followed by bromoxynil + MCPA (247+247 g a.i ha^-1) was provide to be the most effective herbicide against weeds and resulted in maximum wheat yield.