Bio-efficacy of Selected New Generation Insecticides and Azadirachtin against Legume Pod Borer (Maruca vitrata) Infesting Cowpea
Zadda Kavitha *
Krishi Vigyan Kendra, TNAU, Aruppukottai, Tamil Nadu, India.
C.Vijayaraghavan
Cotton Research Station, TNAU, Srivilliputhur, Tamil Nadu, India.
*Author to whom correspondence should be addressed.
Abstract
In the present study, various combinations of newer generation insecticides and azadirachtin were tested and among them, chlorantraniliprole followed by flubendiamide and novaluron followed by emamectin benzoate were found to be equally effective in reducing the inflorescence and pod damage by Maruca vitrata in cowpea. The treatments in which botanicals were alternated with insecticides i.e., azadirachtin followed by chlorantraniliprole and azadirachtin followed by novaluron were found to be on par in efficacy with chlorantraniliprole followed by flubendiamide and novaluron followed by emamectin benzoate. Natural enemy population i.e., wasp, spider and coccinellids was more in plots received no insecticide sprays. Next to these, azadirachtin included treatments have recorded more natural enemy population. In insecticides sprayed plots, wasps were not noticed but spiders were found here and there. High yield was recorded in the treatment, chlorantraniliprole followed by flubendiamide with high BC ratio followed by novaluron followed by emamectin benzoate. Treatments in which azadirachtin was alternated with newer insecticides, BC ratio was slightly lower than the chemicals alone sprayed treatments. However, combining the sprays of novel insecticides with azadirachtin was proved to be ecologically safe as these treatments supported natural enemy population.
Keywords: Cowpea, Maruca vitrata, new generation insecticides, azadirachtin, natural enemies, yield