Evaluation of okra (Abelmoschus esculentusL. Moench) cultivars for resistance to okra mosaic virus and okra yellow vein mosaic virus

Okra (Abelmoschus esculentusL. Moench) serves as a vegetable of great food, medicinal and industrial value. The production of the crop is, however, constrained by lack of improved high yielding, virus and pest resistant varieties. The current study sought to identify resistance in ten okra cultivars to okra mosaic disease and okra yellow vein mosaic disease within the coastal savannah agro-ecological zone of Ghana. Enzyme-linked immunosorbent assay (ELISA) detectedOkra mosaic virus(OkMV) andOkra yellow vein mosaic virus (OYVMV) in symptomatic leaves of the ten cultivars. Okra mosaic disease was the most frequently detected in cultivar Adom while okra yellow vein mosaic disease was most abundant in cultivar Labadi dwarf. Mixed infection of OkMV and OYVMV was found in eight cultivars while cultivars F1-Sahari and F1-Kirene were singly infected by OkMV. The highest index of symptom severity for all plants (ISSap) was found in cultivar Kwabenya (2.80) while Togo and Adom had the least (0.30). The index of symptom severity for diseased plants only (ISSdp) varied significantly and was highest in cultivar Kwabenya (3.85). Based on disease incidence and severity, cultivars Adom, Togo, Asutem, Labadi dwarf, Kirikou-F1 and Kwabenya were rated as tolerant while F1-Sahari and Lucky-19F1 were rated as moderately susceptible. F1-Kirene and Clemson Spineless were rated as highly susceptible with disease incidence of 88.6% and 88.5% respectively.