Defense Responses in Cowpea Elicited by Entomopathogenic Fungi Against Aphis craccivora Koch

Use of entomopathogenic fungi for controlling the aphids is well attempted and further substantiation of interaction of entomopathogenic fungus in cowpea plants against aphid were studied in detail. Bioassays were performed with five fungal isolates against cowpea aphid Aphis craccivora Koch. The results revealed that the isolate Beauveria bassiana (NBAIR) recorded the highest mortality of 94.67% at 120 hr (at 5 days after treatment- DAT). The foliar application of its crude formulation @ 10⁸ spores ml^-1 had significant influence on the induction of defense related enzymes and components against A. craccivora infestation in cowpea. Resistant mechanism mediated by entomopathogenic fungi in cowpea against A. craccivora showed sustained and timely induction/ accumulation of defense enzymes. On 4 DAT the enzymes viz., peroxidases, polyphenol oxidases, phenylalanine ammonia lyase, chitinase, catalase and phenolics revealed maximum activity.