Weed Dynamics, Growth, Yield and Correlation Study as Affected by Weed Control Methods in Soybean [Glycine max (L.) Merril.

Abstract

Background: Soybean being a rainy season crops, is heavily infested with weeds thus ultimately affect the crop yield and economic return. Methods: Field experiment was conducted at Birsa Agricultural University, Ranchi during rainy season of 2019 and 2020 under randomized block design replicated thrice with eight different weed control methods viz., imazathapyr 75 g/ha at 20 days after sowing (DAS), imazathapyr 35% + imazamox 35% ready mix (RM) 75 g/ha at 20 DAS, quizalofop ethyl 50 g/ha at 20 DAS, sodium acifluorfen 16.5% + clodinafop propargyl 8% (RM) 125 g/ha at 20 DAS, imazathapyr 2% + pendimethalin 30% (RM) 1 kg/ha at 20 DAS, hand weeding at 20 and 40 DAS, weed free (three hand weeding at 20, 40 and 60 DAS) and weedy check. Result: Among herbicides, application of quizalofop ethyl 50 g/ha recorded higher growth and yield attributes of soybean due to reduced weed density and weed dry matter which resulted in higher weed control efficiency, weed management index, agronomic management index, thereby recorded maximum soybean yield (2065 kg/ha), net return (₹ 54,743/ha) and B:C ratio (2.50). The soybean yield was negatively correlated with weed dry matter particularly with grassy as well as total weed dry matter while plant dry matter accumulation was strongly correlated with soybean yield.