Morphological and biochemical basis of resistance against the pod borers Maruca vitrata F. and Helicoverpa armigera Hübner in cowpea

For determination of morphological and biochemical basis of resistance in cowpea against the pod borers (Maruca vitrata F. and Helicoverpa armigera Hübner), ten cowpea cultivars were evaluated during kharif 2017 and 2018. Results revealed that cultivars having indeterminate growth, yellow flower, light green and short pods as well as long peduncle recorded lower pod borer population. Correlation between different plant morphological characters and the larval population were found non-significant. The cultivars having low protein, high phenol and low total soluble sugars in flowers and immature pods recorded lower the larval population. The correlation between biochemical components of flowers and larval population were found to be non-significant. Biochemical components of immature pods revealed that phenol exhibited significant negative relationship with larval population, whereas, correlation of total soluble sugars of immature pods exhibited significant positive association with larval population. Among the cultivars screened, GC-6 and GC-1605 were found to be consistently resistant based on different morphological and biochemical factors and pod borer infestation. Relatively GC-1609, GC-1611 and GC-2 showed lesser pod borer infestation. GC-1606 was found to be highly susceptible.