Efficacy, crop safety and residual effect of a premix herbicide (metamifop 8%, imazethapyr 4% and imazomox 3% me) on soybean (glycine max L.) and succeeding green gram (vigna radiataL.)

Weed management in soybean faces substantial challenges due to the prevalence of diverse and competitive weed species, limited availability of effective post-emergence pre-mix herbicides and the necessity to balance effectiveness with crop safety and proitability. A ield study 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. The study was laid out with randomized block design with eleven herbicide treatments including each one hand weeding and weedy check and three replicates. The higher dose combination of Metamifop 8% + Imazethapyr 4% + Imazomox 3% ME + Ammonium Sulphate @ 1250 ml -1 ha (T ) demonstrated superior performance, achieving remarkable weed suppression with a reduction in weed density ranging 6 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, 6 soybean plants in T plots reached average heights of 33-34 cm, produced between 6.9 and 7.6 lateral branches, set 8.8 to 9.3 pods per 6 -1 plant, and yielded between 1.95 and 1.98 t ha , values statistically on par with hand weeded treatment (T ), which measured 35.6- 10 -1 36.3 cm in height, 7.3-8.0 branches, 9.3-9.7 pods, and yielded 2.15-2.23 t ha . The moderate dose combination of Metamifop 8% + -1 Imazethapyr 4% + Imazomox 3% ME + Ammonium Sulphate @ 1000 ml ha (T ) recorded almost similar agronomic results, with 5 -1 plants measuring 33.0–33.8 cm in height and achieving a seed yield of 1.94-1.98 t ha , suggesting that an application dose of 1,000 ml -1 ha was optimum for effective weed management. Economic analysis indicated that T had recorded the highest net returns and 5 beneit-cost ratio, followed by treatment T . These results suggested that the post-emergence application of Metamifop 8%, 6 -1 Imazethapyr 4% and Imazomox 3% ME combined with Ammonium Sulphate at 1,000-1,250 ml ha aided an effective weed control and achieved higher grain yield and economic returns. This study identiied an optimal herbicide dose for effective weed control, ensuring crop safety and proitability, thus providing a viable alternative to labour-intensive manual weeding in soybean production