Abstract

A field experiment was conducted during 2012-13, 2013-14 and 2014-15 at Agricultural Research Station, Darsi, Prakasam district, Andhra Pradesh to evaluate Bt liquid formulations and other biopesticides against gram pod borer, Helicoverpa armigera and spotted pod borer, Maruca vitrata in pigeonpea. There were 10 treatments (2 strains of Bt liquid formulation each at two doses, powdered Bt formulation, two doses of Beauvera bassiana, neem formulation, chemical check) including untreated control. Pooled analysis of three years data revealed that two sprays of chlorpyriphos 0.25% at fortnightly interval was significantly superior over other treatments in suppressing the larval population of H. armigera (av. 0.81 larvae/plant) and M. vitrata (av. 0.80 larvae/ inflorescence) on pigeon pea and recorded minimum pod (5.07%) and seed (3.24 %) damage with maximum 16.9 q/ha yield. It was however, at par with the Bt strain NBAII-BtG4 @ 2% in respect of pod damage (5.30%), seed damage (3.91%) and yield (15.3 q/ha). The Bt strain NBAII-BtG4 @ 2% ranked next best to the insecticidal spray in recording surviving larval population of H. armigera (av. 1.01 larvae / plant) and M. vitrata (av. 1.10 larvae / inflorescence). Moreover, the treatment PDBC-BT1 @ 2% was also found to be equally effective to superior ones. It is therefore biopesticides should be encouraged as eco-friendly insecticides

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