Some aspects of pod characteristics predisposing pigeonpea ( Cajanus cajan (L.) Millsp.) to infestation by Callosobruchus chinensis (L.)

Abstract

Investigations with pigeonpea ( Cajanus cajan) genotypes ‘Apio-elina’ and ‘PI-397566’ showed that certain pod characteristics influenced both infestation in the field by Callosobruchus chinensis and damage caused by this pest. Compared to pods with no or sparse hair, pods with thick hairs suffered greatly reduced field infestation due to the barrier effect of the hairs on oviposition and larval penetration. Even on pods with no or few hairs, the pod wall appeared to offer some resistance to both larval penetration and adult emergence. High levels of infestation by C. chinensis were recorded on pigeonpea pods with no or few hairs, those with pods damaged through shattering, and those with pods that had been previously damaged by pod borers. From the results of the study, it was recommended that pigeonpea selection should include screening for high pod hair density and thicker pod wall.