Identification and Pathogenicity of Fungi Responsible for Foliar Diseases of Groundnut (Arachis hypogaea L.) in Lafia

Foliar diseases of groundnuts are important determinants of yield and productivity of the crop. The aim of this study was to identify and evaluate the pathogenicity of fungi responsible for foliar diseases of groundnut in Lafia. Tissues of groundnut leaves showing signs of discoloration, and spots, were cultured on potato dextrose agar (PDA) for isolation of in-dwelling fungi. A total of 48 isolates belonging to five genera, namely Fusarium, Rhizomucor, Curvularia, Epicoccum, and Aureobasidium were recovered. The identified species were Fusarium incarnatum, Rhizomucor spp., Curvularia lunata, Epicoccum nigrum, and Aureobasidium pullulans. Results of pathogenicity test showed that Rhizomucor spp. produced the highest leaf spots (60.00%), followed by Aureobasidium pullulans (55.00%), Epicoccum nigrum (30.00%), Curvularia lunata (16.67%), and Fusarium incarnatum (12.33%). However, differences in the severity of leaf spots caused by the different fungal pathogens were not significant (P>0.05). The study revealed that fungi isolated from symptomatic leaves of groundnuts were pathogenic, producing varying percentages of leaf spots on inoculated leaves. Therefore, there is a need to control fungal contamination of groundnut leaves in order to improve crop health and enhance yield of groundnuts.