Bio-eficacy, crop safety and implications of premix herbicide combination (metamifop 8%, imazethapyr 4% and imazomox 3% me) on soybean and residual effect on green gram

A field trial was conducted for two consecutive years, 2021-2022, to assess the performance, crop safety and proitability of soybean on the effects of pre-mix herbicide combinations and residual effect on green gram. Weed management in soybean faces signiicant challenges due to the prevalence of diverse and competitive weed species, the limited availability of effective post-emergence herbicides, and the necessity to balance effectiveness with crop safety and proitability. The higher dose combination of Metamifop -1 8% + Imazethapyr 4% + Imazomox 3% ME + Ammonium Sulphate @ 1250 ml ha (T ) demonstrated superior performance, 6 achieving remarkable weed suppression with a reduction in weed density ranging from 79-95%, 78-86%, and 80-90% at 15, 30 and 45 DAA, alongside a decrease in weed dry weight by 79-86%, 87-93%, and 77-93% compared to untreated control plots. The weed control eficiency for T surpassed 77% at all intervals recorded. Correspondingly, soybean plants in T plots reached average heights 6 6 -1 of 33-34 cm, produced between 6.9 and 7.6 lateral branches, set 8.8 to 9.3 pods per plant, and yielded between 1.95 and 1.98 t ha , values statistically on par with hand weeded control (T ), which measured 35.6-36.3 cm in height, 7.3-8.0 branches, 9.3-9.7 pods, and 10 -1 yielded 2.15-2.23 t ha . The moderate dose combination of Metamifop 8% + Imazethapyr 4% + Imazomox 3% ME + Ammonium -1 Sulphate @ 1000 ml ha (T ) recorded almost similar agronomic results, with plants measuring 33.0–33.8 cm in height and 5 -1 -1 achieving a seed yield of 1.94-1.98 t ha , suggesting that an application dose of 1,000 ml ha is optimum for effective weed management. Economic analysis indicated that T has recorded the highest net returns and beneit-cost ratio, followed by treatment 5 T . These results suggest that the post-emergence application of the Metamifop-Imazethapyr-Imazamox mixture combined with 6 -1 Ammonium Sulphate at 1,000-1,250 ml ha helps in effective weed control and achieves higher grain yield and economic returns in soybean cultivation. The study identiies an optimal herbicide dose for effective weed suppression, ensuring crop safety and proitability, thus providing a viable alternative to labour-intensive manual weeding in soybean production systems.