Reactions of some Cowpea (Vigna unguiculata L. Walp) Cultivars Genotypes to Blackeye Cowpea Mosaic Virus Disease

Abstract

Cowpea is a dependable source of protein for human growth and development. The crop is widely cultivated in Sub-Saharan Africa including Nigeria. In spite of its numerous uses, infection by Blackeye cowpea mosaic virus (BICMV) constitutes a serious problem to cowpea productivity and once plants are infected, there is no remedy as in the case of other pathogens such as bacteria, fungi and nematodes. Cultivation of resistant genotypes is cost effective, ecologically sound and sustainable strategy against the pathogen. Twenty-five cowpea genotypes with differential yield and resistance background were evaluated against BICMV infection on the field. Cowpea seedlings were inoculated at ten days after sowing. The plants were observed for BICMV disease incidence, disease severity, growth and yield parameters. The data collected were subjected to analysis of variance. Cowpea genotype IT97K – 568 – 18 was observed to have the lowest disease incidence of 22.2%. However, the genotypes IT07K – 292 – 1 – 10 and IT07K – 299 – 6exhibited the lowest disease severity score of 2.3. Seed weight of 1.5 g per plant was highest in IT97K – 568 – 18. Therefore, the genotype IT97K – 568 – 18 is recommended for cultivation in areas that are prone to BICMV disease. This genotype probably contains tolerant genes to BICVM that could be explored for breeding purposes.