Integrated Weed Management for Enhanced Growth and Yield Performance of Soybean (Glycine max L.)

Abstract

Soybean (Glycine max L.) is a vital oilseed and pulse crop, but its productivity is severely constrained by weed competition, causing yield losses of up to 30–80%. To address this, a field experiment was conducted during the kharif seasons of 2019 and 2020 at the Agronomy Farm, School of Agricultural Sciences, Nagaland University, Medziphema, Nagaland, on acidic sandy loam soils under rainfed conditions. The study followed a randomized block design with eight treatments to evaluate the effect of integrated weed management (IWM) on soybean growth and yield. Treatments included pre- and post-emergence herbicides (Pendimethalin, Imazethapyr, Sulfentrazone) either alone or combined with intercultivation (IC) or hand weeding, along with unweeded control. Results indicated significant differences among treatments. IC at 20 DAS followed by hand weeding at 40 DAS (T7) recorded the maximum plant height (60.90 cm), number of branches (5.20), and dry matter accumulation (2.36 g plant⁻¹). The same treatment also produced the highest grain yield (2064.67 kg ha⁻¹), stover yield (2458.79 kg ha⁻¹), and biological yield (4523.46 kg ha⁻¹). Herbicide + intercultivation treatments such as Imazethapyr fb IC (T4) and Pendimethalin fb IC (T2) also performed well, whereas the unweeded control consistently recorded the lowest growth and yield, with ~52% reduction in grain yield compared to T7. The findings suggest that integrated weed management, particularly the combination of intercultivation and hand weeding, ensures season-long weed control, enhances crop growth, and maximizes soybean productivity in acidic rainfed soils of Northeast India.