Journal of Experimental Agriculture International

Dolichos bean (Lablab purpureus (L.) Sweet) is an important pulse-cum-vegetable crop cultivated extensively in India, and the pod-sucking bug, Coptosoma cribraria Fabricius, is a major field constraint. A field experiment was conducted during kharif 2015-16 and 2016-17 at the Horticultural Garden, College of Agriculture, Rajendranagar, Hyderabad, Telangana, to evaluate the bioefficacy and economic returns of selected insecticides against C. cribraria. The experiment was laid out in a randomised block design with nine treatments and three replications. Eight insecticidal treatments and an untreated control were evaluated, and three foliar sprays were applied at 10-day intervals beginning at 50 per cent flowering. Observations were recorded at 1, 3, 5 and 7 days after spraying, and pooled analyses were used to assess pest suppression, green pod yield and incremental cost-benefit ratio (ICBR). During the first spray, profenophos 50 EC @ 400 g a.i. ha-1 recorded the highest reduction of C. cribraria over the control, with 70.97, 77.03, 86.20 and 75.22 per cent reductions at 1, 3, 5 and 7 days after spraying, respectively. Beta-cyfluthrin + imidacloprid 300 OD @ 30 g a.i. ha-1 and imidacloprid 17.8 SL @ 25 g a.i. ha-1 were the next effective treatments. The highest pooled green pod yield was obtained with flubendiamide 480 SC (3316.0 kg ha-1), followed by chlorantraniliprole 20 SC (3101.5 kg ha-1) and profenophos 50 EC (2826.5 kg ha-1), compared with 1060.5 kg ha-1 in the untreated control. Profenophos 50 EC recorded the highest ICBR (1:13.72), followed by lambda-cyhalothrin 5 SC (1:7.61). The findings indicate that profenophos 50 EC was effective and economically advantageous for managing C. cribraria in Dolichos bean under the study conditions.