Preliminary evaluation of seed and germination traits in cowpea (Vigna unguiculata) genotypes

Cowpea is a valuable crop for subsistence farmers in South Africa. Seed quantitative traits and germination parameters are important for good establishment of the crop, therefore the variation for these traits were determined for 44 cowpea genotypes. A field experiment was conducted at Roodeplaat planted in a randomised complete block design with three replications. Analysis of variance showed significant variation among the genotypes for all traits. Seed length varied from 6.90 to 9.72 mm, while seed width ranged from 5.47 to 7.20 mm. Seed thickness varied from 3.97 to 5.74 mm (mean 4.87 mm). Significant positive correlations were recorded for seed length and seed width; seed thickness and single seed weight; seed width and seed thickness; single seed weight and seed width. Germination speed was also positively correlated to germination percentage. The principal component biplot showed the cowpea genotypes scattered in different quadrants mainly based on seed width, seed length, germination percentage and germination speed. The genotype Vuli showed high values for most germination parameters with good combination of most traits and is highly recommended for use in future breeding.