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

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).