ABSTRACT

Isolation of fungal pathogens of cocoyam was undertaken at both pre and postharvest levels. At the pre harvest level four species of fungi were isolated, characterized and identified from diseased cocoyam leaves to belong to species of Phytophthora, Phylostica, Fusarium and Phythium. At postharvest level, the level the species isolated from diseased cocoyam corms and Cormels included Aspergillus, Fusarium, Penicillium, Rhizopus, yeast and Botryodiplodia with occurrence levels of 100%,60%, 60%, 80%, and 100% and 40% respectively. The occurrences of isolates in pre harvest leaf disease was 80% (Phytophtora) 40% (Phylostica), 60% (Fusarium) and 40% (Phythium). Pathogenicity test result shows that four of the six postharvest disease isolate demonstrated pathogenicity while two (yeast and Rhizopus) proved nonpathogenic. However, the level of pathogenicity varied significantly with Aspergillus niger being the most pathogenic (66.27%) while Penicillium was the least pathogenic (48.0%) Fusarium and Botryodiplodia recorded 48.15% and 49.28% pathogenicity respectively. It was concluded that these were the causative agents of phytopathogenicity in cocoyam after harvest. Constraints of available technology, weather and timing which did not permit test on pathogenicity of the isolates from diseased leaves at pre harvest level. But it will be worthwhile of the pathogenicity test are carried on the phytopathogens isolated during the preharvest period to determine those that are pathogenic to the cocoyam plants.