Genetic Variability and Evaluation of Cowpea [Vigna Unguiculata L.) Genotypes for Resistance to Cowpea Aphid Borne Mosaic Virus

Cowpea (Vigna unguiculata (L. Walp) is one of the most important leguminous crop to mankind because of its use as food, soil cover and  Nitrogen fixation. Despite this, viral diseases have been reported to be a major biotic constrain against cowpea production and can lead  to total crop failure (100% yield loss). Field studies were conducted using 44 cowpea varieties laid down in Randomized Completely Block  Design (RCBD) with three replications. There was a significant difference P ≤ 0.05 for disease incidence among cowpea genotype in both  locations and for both seasons except for incidence in Minjibir 2021. IT17-1157-3-2 recorded the least disease incidence (7.33), while  IT18KD-391 recorded the highest disease incidence (32.08). In total, six genotypes showed resistant response, twenty showed tolerant and the remaining eighteen genotypes showed susceptible response. In terms of location, BUK 2022 recorded the highest disease  incidence (34.30%) while Minjibir 2021 had the least incidence (1.33%). The results of genetic variability indicated that there was a  considerable variability response to cowpea aphid borne mosaic virus (CABMV) which to a larger extent is influenced by the environment,  as evidenced by the higher environmental variance (EV), environmental coefficient of variation (ECV), and lower heritability  values.