Efficacy of biorational insecticides against aphids, Aphis craccivora in amaranthus

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).