Studies on insecticide efficacy and application schedule for management of blister beetles on greengram

On account of its association with flowering phase, adult blister beetles inflict huge losses in short duration crops like greengram. Management of blister beetles is difficult because of their wider host range and high mobility. The experiments wereconducted atPulsesResearch Unit, DrPDKV,Akola, during Kharif season 2012–2013. Evaluation of insecticides for the management of blister beetles revealed application of cypermethrin 10 EC @ 0.01%, chlorpyriphos 50 EC + cypermethrin 5 EC @ 0.1375% and lambda cyhalothrin 2.5 EC @ 0.00375% as most effective insecticides in minimizing the adult blister beetles abundance; translating in higher grain yield of 9.8, 9.6 and 9.4 q/ha, respectively. The incremental cost benefit analysis revealed superiority of cypermethrin (1: 12.2), alphamethrin 20 EC @ 0.05% (1: 10.4) and lambda cyhalothrin (1: 9.48). The experiment on standardisation of the application schedule for management of blister beetles revealed superiority of insecticide, cypermethrin 10 EC @ 1 ml/lit (I₁) in terms of lowest beetles abundance per meter row length (mrl), highest yield per hectare and highest ICBR. It was followed by acephate 75 SP @ 2 g/lit (I₂). Efficacy of fenvalerate dust 0.4% (I₃) was not comparable with these superior treatments. Most effective spraying schedule, (S₃) three sprays -at 7 days interval with first application at bud initiation resulted in minimum count of blister beetles/mrl, followed by (S₂) two sprays -at 10 days interval with first application at bud initiation (S₂). Cost effectiveness of treatments revealed superiority of two applications of cypermethrin 10 EC 1 ml/lit (I₁XS₂) and acephate 75 SP 2 g/lit (I₂XS₂) at 10 days interval commencing first application at bud initiation.