Comparative performance of Haloxyfop-R-methyl formulations on weed suppression, growth and energy use in soybean (Glycine max L.) cultivation

Soybean cultivation during the rainy (Kharif) season frequently encounters severe weed infestations, which compete with the crop for essential resources and result in substantial yield losses if not effectively managed. To address this challenge, a field experiment was conducted during the 2022-2023 rainy season at the Agricultural Research Farm of Banaras Hindu University, Varanasi, Uttar Pradesh, India. The study employed a randomized block design with three replications and eight treatments, comprising different doses and sources of haloxyfop-R-methyl 10.5 % EC, propaquizafop 10 % EC, a weed-free plot and an untreated control. Among the herbicidal treatments, haloxyfop-R-methyl 10.5 % w/w EC (BCSPL sample) applied at a concentration of 0.33 g/L (T3) demonstrated the most effective weed suppression, which translated into improved crop growth and higher yield performance. This treatment significantly reduced weed density and biomass accumulation, thereby enhancing weed control efficiency, weed control index, treatment efficiency index and crop resistance index, while simultaneously lowering the weed persistence index. As a result, T3 recorded a higher stover yield of 2152 kg/ha and a seed yield of 1499 kg/ha, along with an improved harvest index of 41.22 %. Additionally, substantial increases were observed in energy use efficiency (49.14 %), energy efficiency ratio (50.63 %), energy productivity (50.81 %) and energy profitability (53.83 %) in comparison to the untreated control. Thus, haloxyfop-R-methyl 10.5 % w/w EC (BCSPL sample) at 0.33 g/L represents a viable, efficient and sustainable weed management strategy for maximizing soybean productivity and profitability under rainy season conditions in the eastern Indo-Gangetic plains of India.