Efficacy of pre- and post-emergence herbicides in managing weeds and improving productivity of rice under new alluvial zone

AbstractAn experiment was conducted during two consecutive Kharif seasons of 2020 and 2021 at Kalyani D- Block Research Farm, BCKV, Mohanpur, West Bengal, India. The objective was to study the efficacy of pre- and post-emergence herbicides in managing weeds and improve grain yield of transplanted rice. The dominant grassy weeds in fields were: Echinochloa colona, Cynodon dactylon, Panicum repens; broad-leaved weeds were: Ludwigia parviflora, Malva neglecta, Eclipta alba and Alternanthera philoxeroides and sedges were: Cyrus iria and Fimbristylis miliacea. Pre-emergence application (PE) of pretilachlor 50 % EC (pretilachlor) 0.70 kg/ha followed by (fb) passing of conoweeder and sequential application of pretilachlor 0.70 kg/ha PE fb post-emergence application (PoE) of bispyribac-Na 10% SC (bispyribac-Na) 25 g/ha were highly effective in providing effective weed control with greater productivity and profitability. The sequential application of pretilachlor 0.70 kg/ha PE fb bispyribac-Na 25 g/ha PoE provided broad-spectrum weed management, higher crop productivity, and profitability in transplanted rice without any tracible residues in the rice grain and in the soil after harvest.