GENETIC-ANALYSIS OF YIELD AND ITS COMPONENTS IN VEGETABLE COWPEA (VIGNA-UNGUICULATA L. WALP)

The F2 and backcrosses of a cross between two vegetable cowpea (Vigna unguiculata L. Walp) varieties with contrasting characteristics were e valuated for pod yield and its components, with the aim of understandi ng the genetic basis of these characteristics. A four-parameter model incorporating the additive, dominance and additive x additive genetic components fitted the data for pod yield and clusters per plant. The a dditive and additive x additive effects were positive and were larger than the dominance component. The relatively large additive and the pr edominantly positive dominant effects suggest that selection would be effective. Pod weight had high broad (84%) and narrow sense heritabili ty (75%) and can be effectively selected for in the early generations. The study suggested that vegetable cowpea improvement programs should focus on selecting for clusters per plant and average pod weight in t he early generations, while selection for dry pod yield could be delay ed to later generations. It was concluded that pods per plant may be a useful selection criterion in multi-location trials aimed at selectin g for stability of yield.