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

Investigations with pigeonpea (Cajanus cajan) genotypes 'Apio-elina' and 'P I-397566' showed that certain pod characteristics influenced both infestati on 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 gr eatly reduced field infestation due to the barrier effect of the hairs on o viposition and larval penetration. Even on pods with no or few hairs, the p od wall appeared to offer some resistance to both larval penetration and ad ult emergence. High levels of infestation by C. chinensis were recorded on pigeonpea pods with no or few hairs, those with pods damaged through shatte ring, and those with pods that had been previously damaged by pod borers. F rom the results of the study, it was recommended that pigeonpea selection s hould include screening for high pod hair density and thicker pod wall. (C) 1998 Elsevier Science Ltd. All rights reserved.