Determination of growth and seed weights in cowpea (Vigna unguiculata L. Walp) genotypes due to Cowpea aphid-borne mosaic virus infection

Abstract

Cowpea is an important food source for man and livestock feed in sub-Saharan Africa. It is also integrated in the traditional cropping system with the aim of improving soil fertility. Unfortunately, growth and seed production are hampered by several viruses, one of which is Cowpea aphid-borne mosaic virus (CABMV). To date, use of resistant varieties is the best management approach. The objective of this study was to identify cowpea genotypes with desirable growth and seed weight. Twenty four cowpea genotypes were evaluated against CABMV using completely randomised design with three replications. Cowpea seedlings were mechanically inoculated with virus extract at 10 days after sowing. Plant height, number of leaves per plant, leaf diameter and seed weight per plant were recorded. Data were subjected to analysis of variance and significant mean separation was accomplished with Duncan Multiple Range Test at p≤0.05. The virus impacted severely on the cowpea plants. However, the cowpea genotypes 98K-1092-1 and 11D-24-40 were the best for seed weight per plant (1.4 - 1.6 g). Therefore, both genotypes are recommended to farmers in areas that are prone to CABMV infection in order to enhance food sufficiency and nutrition security.