EFFICACY OF VARIOUS PRE AND POST-EMERGENCE HERBICIDES TO CONTROL WEEDS IN WHEAT

The efficacy of various pre and post-emergence herbicides viz. pyroxasulfone @ 0.15 kg a.i. ha^-1, terbutryn + triasulfuron @ 0.18 kg a.i. ha^-1 and flufenacet + pyroxasulfone @ 0.24 + 0.15 kg a.i. ha^-1 as pre-emergence while flufenacet @ 0.24 kg a.i. ha^-1, carfentrazone ethyl + isoproturon @ 0.018 kg a.i. ha^-1, bromoxynil + MCPA @ 0.49 kg a.i. ha^-1 as post-emergence and hand weeding at (20 40 DAS) with a weedy check were tested against narrow and broad leaved weeds in wheat during Rabi season 2008-09. The results revealed that Fumaria indica, Melilotus indica and Rumex dentatus density significantly decreased by all the herbicides compared with control. Bromoxynil + MCPA @ 0.49 kg a.i. ha^-1 as post-emergence application was most effective in controlling F. indica, M. indica and R. dentatus with maximum mortality at both (30 60 DAS) without being phytotoxic to wheat. Bromoxynil + MCPA @ 0.49 kg a.i. ha^-1 as post-emergence spray proved significantly better than other herbicide treatments as it severely reduced the weeds biomass as compared to weedy check. Spikebearing tillers (355.75), spike length (15.07 cm), number of grains spike-1 (52.00) and 1000-grain weight (54.00 g) were maximum in bromoxynil + MCPA @ 0.49 kg a.i. ha^-1 as post-emergence treated plots, which ultimately enhanced the yield up to 39.13% over control. Bromoxynil + MCPA @ 0.49 kg a.i. ha^-1 as post-emergence gave the maximum net income of Rs. 97345 ha^-1. However, maximum MRR (%) of 191730 was obtained with the use of bromoxynil + MCPA followed by flufenacet with the MRR (%) of 67590.