Effect of post-emergence herbicides on weed dynamics and yield of soybean [Glycine max (L.) Merrill]

The present research entitled “Effect of post-emergence herbicides on weed dynamics and yield of soybean [Glycine max (L.) Merrill]” was conducted during kharif, 2023 at Research cum Instructional Farm, College of Agriculture, Raipur, Chhattisgarh. Experiment was conducted in randomized block design with 3 replications and 8 treatments viz, propaquizafop 2.5% + imazethapyr 3.75% ME 120 g a.i. ha-1 (T1), fluazifop-P-butyl 11.1% + fomesafen 11.1% SL 250 g a.i. ha-1 (T2), clethodim 25% EC 150 g a.i. ha-1 (T3), flumioxazin 50% SC 125 g a.i. ha-1 (T4), pyroxasulfone 85% WP 127.5 g a.i. ha-1 (T5), haloxyfop-R-methyl 10.5% EC 125 g a.i. ha-1 (T6), hand weeding twice (20 and 40 DAS) (T7) and weedy check (T8). Results revealed that growth attributing character viz, plant height, number of branches, number of leaves, dry matter accumulation, crop growth rate, leaf area index as well as yield attributing parameters viz, number of pod plant-1, number of seeds pod-1, seed index, seed yield, harvest index were found significantly maximum under hand weeding twice (20 and 40 DAS) followed by propaquizafop 2.5% + imazethapyr 3.75% ME 120 g a.i. ha-1. Minimum values of above characters were observed in weedy check. Lowest weed density and weed dry matter production was obtained in hand weeding twice (20 and 40 DAS) which was followed by propaquizafop 2.5% + imazethapyr 3.75% ME 120 g a.i. ha-1, whereas highest weed density, weed dry matter production and weed index was found under weedy check. In terms of economics, maximum gross return and net return were fetched under hand weeding twice (20 and 40 DAS) followed by propaquizafop 2.5% + imazethapyr 3.75% ME 120 g a.i. ha-1 but maximum B: C ratio was found under propaquizafop 2.5% + imazethapyr 3.75% ME 120 g a.i. ha-1 and lowest gross return, net return and B:C ratio were received under weedy check.