Chemical weed control in soybean (Glycine max)

A field experiment was conducted during rainy (kharif) season of 1995 and 1996 on alluvial soils of Agronomy Research Centre of College of Agriculture, Gwalior (M.P.). Pre-emergence application of alachlor and pendimethalin @ 1.50 kg/ha were comparable with two hand-weedings (20 and 30 DAS) in reducing the weed density and weed biomass, and increasing the weed-control efficiency as well as number of pods/plant and weight of pods. Pooled data showed that except the weed-free treatment, next in higher order was the treatment of two hand weedings, which gave maximum seed yield (12.45 q/ha) followed by alachlor @ 1.5 kg/ha. However, alachlor at 1.5 kg/ha was on a par with penedimethalin 1.5 kg a.i./ha as pre-emergence and fluchloralin 1.5 kg a.i./ ha as pre-plant application.