Occurrence of cowpea viruses in the forest and savannah agro-ecological zones of Ghana

Abstract

Cowpea (Vigna unguiculata (L.) Walp) is a major grain legume in Sub Saharan Africa whose production is heavily affected by viral diseases. A disease survey and antigen-coated plate enzyme-linked immunosorbent assay (ACP-ELISA) were used to determine the incidence, severity and occurrence of viruses infecting cowpea in some major growing areas in the Ashanti and Brong Ahafo regions of Ghana. The survey revealed the highest virus incidence (81.6%) and severity (3.01) in Ejura, and the least incidence (46.7%) and severity (2.38) in Nkoranza. The ACP-ELISA results indicated that Blackeye cowpea mosaic virus (BICMV) was the most prevalent virus, with occurrence ranging from 32% in Mampong to 60% in Atebubu. Cucumber mosaic virus (CMV) was the least detected, occurring only in samples from Nkoranza (4%). Cowpea mild mottle virus (CPMMV), Cowpea mottle virus (CPMoV), Southern bean mosaic virus (SBMV), Cowpea aphid borne mosaic virus (CABMV) and Cowpea yellow mottle virus (CYMV) were also detected in the samples. The prevalence of these viruses suggest the need for continuous monitoring of cowpea fields in the country to ensure effective disease management.