Indirect selection for resistance to Alectra vogelii (benth) infestation in cowpea (Vignaunguiculata (L) walp)

Alectra vogelii (benth) is a parasitic weed which causes significant yield reductions in cowpeas (VignaunguiculataWalp) in most of the sub-Saharan African countries. The objective of this study was to establish the effect of Alectra vogelii infestation on yield components of cowpea and the prospects of utilizing these components for indirect select to A. vogelii in resistance breeding. Seven genotypes of cowpea were crossed in all possible combinations without reciprocals and their 21 F2 progeny including parents were evaluated for reaction to Alectra vogelii infection at two locations, Ilonga and Hombolo. The experiments were laid using a Randomized Complete Block Design with three replications. Significant (P < 0.001) genotypic responses to Alectra emergency and infestation were found. A significance negative correlation was found between the Alectra emergency and infestation to yield and yield components (P< 0.01 and P< 0.001). However, both yield components (Number of pods per plant and 100 seed weight) tested exhibited a weak r2 value (< 0.25) implying that these components can only be used to supplement and not as a substitute to direct selection in breeding for resistance to A. vogelii.