Effect of herbicides on weed dynamics and productivity of soybean

A field experiment was conducted at Birsa Agricultural University, Ranchi, Jharkhand, during rainy (Kharif) season of 2019 to study the efficacy of herbicides on weed dynamics and productivity of soybean. The treatments comprised of: post-emergence application (PoE) of imazethapyr 75g/ha at 20 days after sowing (DAS), imazethapyr + imazamox 75 g/ ha PoE 20 DAS, quizalofop-ethyl 50 g/ha PoE 20 DAS, sodium-acifluorfen + clodinafop-propargyl 125 g/ha PoE, imazethapyr + pendimethalin 1.0 kg/ha PoE, hand weeding twice at 20 and 40 DAS, weed free (hand weeding thrice at 20, 40 and 60 DAS), and weedy check. A randomized block design with three replications was used. Quizalofop-ethyl 50 g/ha PoE recorded maximum yield attributes, viz. number of pods /plant (48), number of seeds/pod (2.73), 100 seeds weight (12.46) and yield of soybean (2.15 t/ha) owing to reduced weed biomass and higher weed control efficiency (73.33%) during initial crop growth stage and realized maximum net return (₹ 57221/ha) and B:C ratio (2.34).