Zakari, B.G, Chimbekujwo I.B.,
Isolation and identification of the fungal pathogens of postharvest rots of pepper were carried out on rotted pepper fruits obtained from five markets (Jimeta Modern, Jambutu, Pallujah, Jimeta Shopping Complex and Lake Gariyo Markets) in Yola using Potato dextrose Agar (PDA). Aspergillus niger was frequectly isolated with 34.7%, followed by Aspergillus flavus, Botrytis cinerea, Colletotrichum capsici and Phytophthora capsici with 21.3%, 20%, 10% and 10.7% respectively. Pathogenicity tests on fresh pepper (Capsicum annuum, Capsicum chinense and Capsicum frutescens) fruits revealed that all the fungal isolates were pathogenic on the three pepper species. Among the five isolates, Aspergillus niger exhibited the highest level of virulence with 75% of rots covering the fruit surface while Phytophthora capsici had the least with 25% of the fruit rot surface. Effect of various concentrations of ethanolic extracts from the leaves of Azadirachta indica, Tridax procumbens and Vernonia amygdalina was carried out in-vitro under laboratory conditions. The efficacy of leaf extracts of the test plants against the five fungi isolates at different concentrations (20%, 40%, 60% and 80 %) revealed that ethanol extracts suppressed the mycelial growth of the five pathogens. The inhibition effect was proportional to concentration used. For ethanol extraction, Azadirachta indica was more effective on Aspergillus niger (86.87%), Tridax procumbens was also more effective on Aspergillus niger (88.03%), just as Vernonia amygdalina was also more effective on Aspergillus niger (87.21%). Statistically, mean diameter of mycelial growth differred significantly among concentrations and among plant extracts. Higher concentration of ethanol favoured higher mycelial growth reduction.