Effect of Bio-rational approaches on pigeon pea pod and grain damage by Helicoverpa armigera (Hüb.)

The bio-rational approach that included intercropping and application of eco-friendly bio-pesticides had significantly reduced the pod and grain damage (in number and by weight basis) inflicted by Helicoverpa armigera. The pod and grain damage in the intercrops pigeon pea + rice, pigeon pea + sorghum, pigeon pea + pearl millet, pigeon pea + maize and pigeon pea + black gram variedsignificantly from untreated pigeon pea sole crop. Two sprays of eco-friendly bio-pesticides (NSKE 5%, Bt and Nimbecidine) were found superior over one spray of bio-pesticide in reducing the pigeon pea pod damage, grain damage and grain weight loss. Among the various treatments, pigeon pea + rice followed by pigeon pea + sorghum sprayed with NSKE 5% (first at flowering & pod formation stage and second after 20 days) was found most effective in reducing the damage inflicted by gram pod borer.