Influence of nitrogen and weed management practices on growth and yield of blackgram (Vigna mungo)

Abstract

A field experiment was conducted during 2025 at the Agricultural Farm, Mewar University, Gangrar, Chittorgarh, Rajasthan, to evaluate the influence of different nitrogen levels and weed management practices on the growth and yield of blackgram (Vigna mungo). The study comprised ten treatment combinations, involving nitrogen doses of 15, 30, and 45 kg/ha, and three weed control methods—hand weeding twice (at 20 and 40 days after sowing), pre-emergence application of Pendimethalin, and post-emergence application of Imazethapyr—along with a control receiving the recommended NPK dose (20:40:20 kg/ha). The experiment was laid out in a randomized block design with three replications. Results revealed that the treatment with 45 kg/ha nitrogen combined with post-emergence application of Imazethapyr (75 g/ha) (Treatment T9) significantly outperformed all other treatments. It recorded the highest plant height (64.49 cm), number of branches per plant (6.47), nodules per plant (34.33), dry matter accumulation (16.54 g/plant), pods per plant (32.13), and seeds per pod (8.20). The same treatment also achieved the highest seed yield (1223.33 kg/ha), stover yield (2472.67 kg/ha), gross return (₹83,109/ha), net return (₹55,489.05/ha), and benefit-cost ratio (2.01), along with the lowest weed density (9.44/m²). These findings suggest that integrating higher nitrogen levels with effective post-emergence weed management substantially improves the productivity and profitability of blackgram cultivation under field conditions.