Reactions of commercial cultivars of okra, pepper, and tomato to cucumber mosaic virus disease

Abstract

Okra (Abelmoschus esculentus), pepper (Capsicum spp.) and tomato (Solanum lycopersicum) are rich sources of minerals and vitamins required by humans for normal growth and development. However, the productivity of these vegetables is seriously constrained by Cucumber mosaic virus (CMV) disease. To date, adoption of resistant cultivars is the most effective, ecologically sound and sustainable management strategy against the disease. Therefore, selected cultivars of okra (Clemson Spineless, Ex Bassawa -2 and NHAe 47 - 4), pepper (California Wonder, Cayenne and Yolo Wonder) and tomato (Roma Savanna, Tropimech, and UC82B) were evaluated for resistance to CMV. The experiment was conducted under screenhouse and field conditions in Minna, Southern Guinea Savanna zone of Nigeria. Completely randomised design with six replications was used in screenhouse while the field trial was laid out using randomised complete block design with three replications. Seedlings were inoculated with CMV at 10 days after emergence. Disease incidence, disease severity, growth and yield characteristics were recorded. Data were subjected to analysis of variance at p ≤ 0.05. Infected plants elicited mosaic symptoms but disease severity was cultivar dependent. Plant height, leaf area, fruit length, fruit diameter and fruit weight were all reduced by CMV. The lowest disease incidence ( < 35 %), severity ( < 3), reductions in morphological and yield parameters ( < 10 %) were found in Ex- Bassawa-2, Cayenne, and Roma Savanna. This indicated that they contained CMV tolerant genes. Therefore, the three most tolerant cultivars (Ex- Bassawa-2 cultivar of okra, Cayenne of pepper and Roma Savanna of tomato) are recommended to farmers in CMV prone areas.