Efficacy of botanical insecticides against pod borer (Maruca vitrata) on cowpea (Vigna unguiculata)

Abstract

The field experiment was conducted during kharif 2016-17 to evaluate botanical insecticides against pod borer on cowpea. Two sprays of insecticides were done at fifteen days interval. The most effective treatment against pod borer was Chlorpyriphos 20 EC@ 300g a.i. ha-1 after first spray (1.97, 1.74 and 1.53 larvae m-2 at 3, 5, and 7 days after spray, respectively) and second spray (1.51, 1.54 and 1.93 larvae m-2 at 3, 5 and 7 days after spray, respectively) followed by Neem oil @ 2 per cent first spray (4.30, 4.08 and 3.52 larvae m-2 at 3, 5 and 7 days after spray, respectively) and second spray (3.00, 2.85 and 3.28 larvae m-2 at 3, 5 and 7 days after spray, respectively); and NSKE @ 5 per cent after first spray (4.62, 4.18 and 3.81 larvae m-2 at 3, 5 and 7 days after spray, respectively) and second spray (3.12, 3.09 and 3.37 larvae m2 at 3, 5 and 7 days after spray, respectively). The maximum larval population was found in untreated plot. The highest green pod yield of cowpea was recorded in plants sprayed with Chlorpyriphos 20 EC @ 300 g a.i. ha-1 (53.12 qha-1) followed by Neem oil @ 2 per cent (43.53 qha-1) and NSKE @ 5 per cent (42.11 qha-1), while lowest yield was recorded in untreated control plot (32.16 qha-1).