Weed control efficiency of post emergence herbicides and their effect on productivity of cluster bean [Cyamopsis tetragonoloba(L.) Taub.]

A field experiment was undertaken to evaluate the performance of different weed control treatments in cluster bean during kharif, 2011 at Tabiji, Ajmer in randomized block design with three replications. Treatment of weed free check was found best by recording highest values of yield attributes, seed (12.20 q/ha), haulm (32.16 q/ha) and biological yield (44.36 q/ha) with maximum weed control efficiency at successive stages. It was at par with Pendimethalin 1.0 kg/ha (PRE) + one hand weeding, imazethapyr 40 g/ha and imazethapyr 60 g/ha at 20 days after sowing (DAS). Among different herbicides treatments, imazethapyr 60 g at 20 DAS showed highest values of yield attributes, seed yield (11.65 q/ha), haulm yield (31.12 q/ha), weed control efficiency (90.1, 88.0 and 83.9 per cent at 30, 60 DAS and at harvest, respectively) and minimum weed index (4.7). In monetary term also imazethapyr 60 g/ha recorded higher net returns (Rs 69030/ha) and benefit-cost ratio (5.31) than season long weed free check (Rs 66990/ha and 4.05, respectively) on account of higher cost of cultivation involved in latter treatment to a tune of Rs 5930/ha.