Abstract

Cowpea is an important grain legume as well as fodder crop, especially in the dry regions of South Africa. The production of this crop has been below average because of low genetic variation and cultivation of poor-yielding varieties which have not been improved. The potentials of cowpea F₂ generation arising from crosses made from 55 exotic parental lines, introduced into South Africa were determined. F₁ lines derived from the crosses were advanced to F₂ lines in the glass-house, and the segregating F₂ families were further evaluated in the field with their parental lines. The following data were collected from the progeny: number of pods per plant, 100 seed-weights, fodder yield, grain yield and harvest index. Results showed that F₂ lines exhibited significant differences on all the parameters studied thus indicating the presence of genetic variability among the segregating progeny. Number of pods per plant, 100 seed-weight and harvest index showed higher significant differences. The F₂ lines obtained a significant increase in number of pods per plant as compared to their parents, thus indicating the potentials of progeny for higher pod production. Harvest index for F₂ lines varied between 0.16 and 0.60 (dual-purpose type), and are mostly medium cowpea types with dual purpose characteristics for producing grain for human consumption and fodder for livestock. These parameters should therefore receive highest priority in developing high yielding dual-purpose varieties. There are several promising F₂ progenies which performed exceedingly well over the parents, so further screening is essential until their full potential is attained.

Key words: Vigna unguiculata, germplasm, harvest index, dual-purpose, 100 seed-weights, segregating population.