Evaluation of Herbicides for the Management of Complex Weed Flora in French Bean (Phaseolus vulgaris L.) under Mid Hill Conditions of Himachal Pradesh, India

A field experiment was conducted at Experimental Farm of the Department of Vegetable Science and Floriculture, CSK HPKV, Palampur during Kharif, 2022 to study the effect of herbicide combinations for the management weeds in French bean (Phaseolus vulgaris L.). The experiment was laid out in Randomized Block Design with three replications and comprised of eleven weed control treatments viz., oxyfluorfen 150 g ha-1 (pre-emergence), pretilachlor 1000 g ha-1 (pre-emergence), imazethapyr 100 g ha-1 (pre-emergence), quizalofop- ethyl 100 g ha-1 ( pre-emergence), oxyfluorfen 100 g ha-1 (pre-emergence) fb quizalofop-ethyl 70 g ha-1 (post-emergence), pretilachlor 700 g ha-1 (pre-emergence) fb quizalofop-ethyl 70 g ha-1 (post-emergence), imazethapyr 70 g ha-1 (pre-emergence) fb quizalofop-ethyl 70 g ha-1 (post-emergence), pretilachlor 500 g ha-1 + imazethapyr 50 g ha-1 (pre-emergence) fb quizalofop-ethyl 50 g ha-1+ chlorimuron 3 g ha-1 (post-emergence), pretilachlor 500 g ha-1+ imazethapyr 50 g ha-1 (pre-emergence) fb HW, 2 HWs (30 and 45 DAS) and weedy check. Results of the study revealed that hand weeding (twice) and pretilachlor 500 g ha-1 + imazethapyr 50 g ha-1 (pre-emergence) fb HW effectively reduced weed count and dry matter of the weed species. Highest weed control efficiency of 75.6 per cent was obtained from hand weeding (twice) treatment followed by 63.7 per cent with pretilachlor 500 g ha-1 + imazethapyr 50 g ha-1 (pre-emergence) fb HW. The treatment, hand weeding (twice) also produced significantly higher pod yield (16.14 t/ha), gross (₹ 2, 83,795) and net (₹2, 66,732) returns due to weed control. Amongst herbicidal treatments, pretilachlor 500 g ha-1 + imazethapyr 50 g ha-1 (pre-emergence) fb HW proved best as it resulted in significantly higher pod yield (14.24 t/ha), gross (₹ 2, 38,006) and net (₹ 2, 31,129) returns due to weed control. The treatment, Imazethapyr 100 g ha-1 gave the highest marginal benefit cost ratio (MBCR) of 178.9.