Efficacy of biorational insecticides against aphids, Aphis craccivora in amaranthus

Abstract

A field experiment was conducted to study the bioefficacy of biorationals against cowpea aphid, Aphis craccivora infesting amaranthus during rabi 2019-20 at the Zonal Agricultural and Horticultural Research Station (ZAHRS), Shivamogga. Out of six biorationals evaluated, the highest per cent reduction of aphid population was recorded in Lecanicillium lecanii 1 × 109 CFU @ 1 g/l (62.87 %), followed by NSKE 5% (53.59%). Concerning the B:C ratio, NSKE 5 % recorded the highest return per rupees invested, i.e., 1: 2.45, followed by azadirachtin 10,000 ppm @ 2 ml/l (1: 2.16) and Beauveria bassiana 1×109 CFU/g @ 1 g/l (1: 2.12).