Optimizing soybean yield, weed dynamics and profitability using herbicides in custard apple-based agri-horti system of the Vindhyan region of Uttar Pradesh, India

A field experiment was conducted during the Kharif seasons of 2021 and 2022 to evaluate the weed management effect on weed suppression, crop growth, yield and economics of soybean within a custard apple-based system. The experiment was laid out in a randomized block design comprising seven treatments with three replications. The treatments included pre-emergence (PRE) of pyroxasulfone 85 % w/w WG (GSP sample) 120.0 mL ha-1 (T1), pyroxasulfone 85 % w/w WG (GSP sample) 150.0 mL ha-1 (T2), pyroxasulfone 85 % w/w WG (GSP sample) 187.5 mL ha-1 (T3), pyroxasulfone 85 % w/w WG (Market sample) 150.0 mL ha-1 (T4); early post-emergence (PoE), imazethapyr 10 % SL WC 1000.0 mL ha-1 (T5), hand weeding at 20 and 40 days after sowing (T6) and untreated control (T7). The hand-weeded plots (T6) recorded significantly the lowest weed density (WD) and weed dry weight (WDW) along with the highest weed control efficiency. Among herbicidal treatments, T3 showed significantly better weed suppression, physiological growth indices, biomass accumulation and grain yield of soybean, followed closely by T2. This treatment also delivered superior net returns and benefit-cost ratio compared to other herbicidal options. The combination of effective weed management using pyroxasulfone 85 % WG (GSP sample) at 150 mL ha-1 (T2) and the agri-horti system proved to be a sustainable and profitable approach for soybean production under the given agro-climatic conditions.