Efficacy of Bacillus thuringiensis Against Maruca vitrata (Geyer) on Cowpea

Abstract

Spotted pod borer, Maruca vitrata (Geyer) is a major constraint in the production of grain cowpea. The pest causes losses in grain yield of cowpea ranging from 20 to 60 per cent. In order to manage the pest, field experiments were conducted at four farmers fields during rabi 2010-2011. The study revealed that the pest can be managed effectively by spraying profenophos @ 1ml/litre at the time of flowering, Bacillus thuringiensis @ 1g/litre one at the time of flowering and next one was at 15 days later, Beauveria bassiana @ 20 g/litre at the time of flowering and other one was at 15 days interval and carbaryl @ 4 g/litre at the time of flowering. At harvest, the treatments recorded the per cent pod borer incidence of 6.99, 7.40, 7.86 and 8.96, respectively. Significantly higher grain yield was recorded in profenophos (817.18 kg/ha), Bacillus thuringiensis (754.89 kg/ha) and Beauveria bassiana (748.66 kg/ha) and carbaryl (669.31 kg/ha) treated plots.