Weed dynamics and productivity of soybean as influenced by different post-emergent herbicides

A field experiment was conducted at Punjab Agricultural University, Ludhiana and Dr J C Bakhshi Regional Research Station, Abohar, Punjab (India), during Kharif (rainy season) 2021to identify effective and economic post-emergent herbicide for managing weeds in soybean and improve productivity of soybean [Glycine max (L.) Merrill]. The experiment consisted of 12 treatments, viz. post-emergence application (PoE) of imazethapyr 75 g/ha; propaquizafop + imazethapyr at 75, 100, and 125 g/ha; sodium-acifluorfen + clodinafop-propargyl at 147, 196, and 245 g/ha; imazamox + imazethapyr at 42, 56 and 70 g/ha; hand weeding (HW) twice at 20 and 40 days after sowing (DAS) and weedy check. A randomized complete block design with three replications was used. The lowest weed density and highest soybean biological and seed yield were recorded with HW twice, which was statistically at par with imazamox + imazethapyr 70 g/ha PoE at 15-20 DAS. It was concluded that imazamox + imazethapyr 70 g/ha PoE at 15-20 DAS improves the soybean seed yield with highest benefit:cost ratio, due to effective broad spectrum weed control.