Field resistance in cowpea, Vigna unguiculata to the cowpea moth, Cydia ptychora

SUMMARY Field evaluation of 26 selected cowpea cultivars showed that several of them had good levels of resistance to Cydia ptychora ; TVu 946, Adzuki, ‘Vita 5’ and Igbirra were the most resistant. Percentage seed damaged by the larvae was positively correlated with days to 50% flowering ( r = 0.39*), days to 50% pod ripening ( r = 0.48*) and weight of 100 seeds ( r = 0.56**). All four cultivars were early maturing, had semi‐determinate or determinate plant types and carried their pods above the leaf canopy. No single morphological character could be related to the degree of seed damage but some association with phenological characteristics was indicated. Earliness, determinacy and uniform pod maturity were important plant characters associated with the expression of field resistance. Even if these characters are not causative, they provide a rational basis for screening of a large germplasm to identify or synthesise materials with greater resistance to this moth.