Indian Journal of Weed Science

Field experiments were conducted to study the bio-efficacy of acetochlor for weed control in soybean during rainy seasons of 1996 and 1997. There was drastic reduction in the density of Echinochloa colona and density and dry weight of total weeds when acetochlor at 500 to 2000 g ha⁻¹ was applied as pre-emergence. Efficacy of acetochlor of E. colona and total weeds increased with the increase in its dose of application from 500 to 2000 g ha⁻¹. On an average, season long weed competition caused 82.0% reduction in the grain yield of soybean when compared with weed-free treatment. Maximum grain yield was observed in weed-free plots, though pre-emergence application of acetochlor at 1.5 and 2.0 kg ha⁻¹, alachlor at 2.5 kg ha⁻¹, pendimethalin and metolachlor each at 1.5 kg ha⁻¹ produced grain yields similar to weed-free treatment.