Vol. 11, Issue 12 (2022)

A Field experiment was carried out at the experimental site of Bihar Agricultural College Farm, Bihar Agricultural University, Sabour during kharif season, 2018, with blackgram (cv ‘IPU 2-43’) to study the efficacy of pre and post emergence of herbicide on weed flora of blackgram (Phaseolus mungo L.) under the soil typic Haplustepts. The experiment was laid out in a randomized block design with three replications and eleven treatments. From the investigation it revealed that Cynodon dactylon among the grasses; Cypres rotundus among the sedges and Phyllanthus niruri, Solanum nigrum, Mimosa pudica among the broadleaved weeds were predominant maximum in number throughout the cropping period. Among herbicide weed treatments, the highest growth, yield parameters and minimum number of weed flora, weed density as well as weed biomass were obtained in weed free followed by intercultural operation at 20 & 40 DAS and it was statistically at par with Pendimethalin (PE) 30 EC @ 0.75 kg a.i /ha fb Imazethapyr (POE) @ 0.060 kg a.i /ha and Oxyfluorfen (PE) @ 0.125 kg a.i /ha fb Imazethapyr (POE) @ 0.060 kg a.i/ha. All chemical treatments increased the growth, seed yield and lowest in weed density, weed biomass compared to weedy check. Weedy check registered with lowest seed yield and maximum number in weed flora and weed density.