Evaluation of Promising Herbicide Combinations for Weed Management in Rajmash (Phaseolus vulgaris L.) under Dry Temperate Conditions of Himachal Pradesh

Alachlor at 1.0 kg ha⁻¹+ pendimenthalin 1.0 kg ha⁻¹, alachlor at 1.0 kg ha⁻¹+ pendimethalin at 0.75 kg ha⁻¹ and alachlor at 0.75 kg ha⁻¹+ pendimethalin at 1.0 kg ha⁻¹ were the most effective herbicide combinations in controlling weeds (Digitaria sanguinalis, Polygollum alarum and Gallillsoga parvijlora). Their effectiveness was similar to hand weeding twice in increasing pods plant⁻¹, seeds pod⁻¹, 1000-seed weight and seed and haulm yields. None of the herbicides alone or in combination controlled Equisetum spp. Alachlor at 1.50 kg ha⁻¹ was not effective against broad-leaved weeds. Lowest control costs (Rs. 1291 ha⁻¹) and highest marginal benefit: cost ratio (MBCR) were obtained due to alachlor at 1.50 kg ha⁻¹. The different herbicide combinations evaluated recorded 3–4 times higher MBCR over the farmer's practice of hand weeding twice.