Bio-efficacy of Flumetsulam, Cloransulam and Diclosulam in Soybean

A field experiment was conducted in loam soil during the rainy season of 2000 in Pantnagar, Uttaranchal, India to investigate the efficacy of flumetsulam (50 and 70 g/ha), cloransulam (35 and 45 g/ha) and diclosulam (25 and 40 g/ha) in controlling weeds in soyabean cv. PK 1162. Other herbicide treatments were: flumetsulam at 50 g/ha+haloxyfop at 50 g/ha; cloransulam at 35 g/ha+haloxyfop at 50 g/ha; diclosulam at 25 g/ha+50 g/ha; chlorimuron ethyl at 6 g/ha; imazethapyr at 75 g/ha; and clomazone at 750 g/ha. flumetsulam, cloransulam and diclosulam, applied alone or in combination with haloxyfop, were applied 12 days after sowing (DAS). Imazethapyr was applied at post-emergence, clomazone at preplant and chlorimuron ethyl at 6 DAS. Flumetsulam, cloransulam and diclosulam were not effective in reducing Echinochloa colona. Flumetsulam effectively reduced the density of Celosia argentea. Cloransulam showed efficacy against Cyperus iria and Parthenium hysterophorus. When flumetsulam, cloransulam and diclosulam were tank mixed with haloxyfop there was no change in the efficacy of flumetsulam, cloransulam and diclosulam, but haloxyfop lost its efficacy against E. colona. Flumetsulam, cloransulam and diclosulam at both rates suppressed soyabean growth. Flumetsulam caused yellowing of soyabean. Grain yields obtained in the treatments with flumetsulam, cloransulam and diclosulam at both rates were lower than those obtained with imazethapyr and the weed free control