Pathogenicity Testing of Fungal Species Isolated from Irish Potatoes

Potatoes (Solanum tuberosum L) are nourishing tubers, highly perishable and susceptible to microbial spoiling and waste due to a lack of adequate storage strategies. This study isolated and identified the fungus species responsible for Solanum tuberosum rotting and determined the pathogenicity of each fugal isolate on healthy Irish potato tubers. Total of thirty (30) spoiled Irish potato tubers were collected from three (3) separate sellers: Badariya, Bello Way, and Gwadangaji areas of Birnin Kebbi. Serial dilution of the samples were performed and inoculated on sterile PDA medium using pour plate method of inoculation. The plates were incubated at room temperature (270C) for six (6) days. The isolates were identified based on their macroscopic and microscopic characteristics. The total fungal count for Bello Way, Badariya, and Gwadangaji was 5.7 ± 4.05, 5.7 ± 3.52, and 5.0 ± 2.65 TFC/g, respectively. Mold isolates discovered were Aspergillus niger 9 (39.13%), Fusarium solani 6 (26.09%), Penicillium digitatum 4 (17.39%), Rhizopus oryzae 1 (4.34%), and Mucor spp 2 (8.70%). Among the other isolates, Aspergillus niger had the highest frequency and percentage of 9 (39.13%). The five fungal isolates had varying average degrees of pathogenicity, with Aspergillus niger causing the most extensive and rapid spoiling (6.8 cm), followed by Fusarium solani (6.2 cm), Penicillium digitatum (6.0 cm), Mucor spp. (4.6 cm), and Rhizopus oryzae (4.5 cm). In conclusion, mold is responsible for the spoilage of Irish potatoes marketed within Birnin Kebbi; therefore, proper handling of potato tubers is required to mitigate fungal infection.