Comparative Efficacy of Different Strategies for Management of Spotted Bollworms, Earias spp. on Okra, Abelmoschus esculentus (L). Moench

Integrated control measures were tested for efficacy against Earias spp. on okra in Pakistan with the over-riding goal of finding the most cost-effective control. Five control methods: (i) biological control with Trichogramma chilonis Ishii., (ii) cultural control of alternate host plants by hand weeding and hoeing, (iii) botanical control by spraying the plants with 5% neem seed kernel extract, (iv) mechanical control by hand-clipping injured plant parts and (v) chemical control with by spraying the plants with a commercial insecticide (Tracer®, Dow AgroSciences). These treatments were tested alone and as seven combinations of two methods and three combinations of three methods. All treatments were applied each week for six weeks and compared by measuring damaged fruits and shoots, yield and cost-benefit ratio in a controlled, replicated field experiment on Diksha cultivar of okra. Fruit and shoot damage was significantly lowest at 7% and 14%, respectively, in the plots treated with only chemical control and fruit yield was highest, at 63 kg/plot, in plots treated with the combination of mechanical and chemical control. Plots treated with only mechanical control had the highest cost: benefit ratio at 1:2.61, followed by plots treated with mechanical control and chemical control, at 1:2.39 and plots treated with chemcial plus botanical plus mechanical control at 1:2.38.