Effect of weed management and sulphur on weed dynamics, soybean (Glycine max) yield and associated quality traits

A field experiment was conducted during rainy seasons of 2011 and 2012 at Udaipur to evaluate the effect of weed control and sulphur on yield and quality of soybean [Glycine max (L.) Merrill]. The twenty eight treatment combinations comprising 7 weed management treatments (weedy check, pendimethalin 1.0 kg ha-1 pre- emergence, quizalofop-ethyl 50 g ha-1 and imazethapyr 100 g ha-1 post-emergence at 15 DAS, pendimethalin, quizalofop-ethyl and imazethapyr followed by hoeing and weeding at 30 DAS) in main plot and 4 rates of sulphur application (00, 20, 40 and 60 kg ha1) in sub plot were laid out in split plot design with three replications. All weed control treatments reduced weed dry matter at harvest during both the years. Pendimethalin followed by hoeing and weeding at 30 DAS was significantly superior in reducing weed dry matter of broad-leaved, narrow-leaved and total weeds at harvest over rest of the treatments. All weed control treatments significantly enhanced straw and biological yield of soybean over weedy check. Pendimethalin followed by hoeing and weeding at 30 DAS produced significantly higher pooled seed (2168 kg ha-1), straw (3167 kg ha-1) and biological (5335 kg ha-1) yields compared to other treatments. Sulphur rates had no significant effect on weed dry matter at harvest. Across the years, increasing level of S application up to 40 kg ha-1 resulted in significantly increased straw yield, biological yield and harvest index of soybean. Increasing rate of sulphur application up to 40 kg ha-1 tended to significantly increase protein and oil yield.