CROSS-PATHOGENICITY ASSAY OF SOME MOLDS ISOLATED FROM STORED Solanum tuberosum (IRISH POTATOES)

Irish potatoes (Solanum tuberosum L.) are an important staple food crop, especially in Nigeria, where postharvest spoilage significantly reduces their availability. This research was conducted to isolate and identify dominant pathogenic fungi from rotting stored Irish potatoes in Lokoja, Kogi State, and to assess their cross-pathogenicity on other stored crops such as yam, ginger, and onion. Altogether, seven fungal species were recovered and characterized: Rhizopus sp., Aspergillus niger, Aspergillus flavus, Fusarium oxysporum, Penicillium sp., Mucor sp., and Aspergillus fumigatus. Pathogenicity tests involving inoculating wounded healthy Irish potato tubers with 4 mm mycelial disc from a 7-day-old fungal culture of the tested fungi and sealed with sterile vaseline confirmed all isolates caused rot on Irish potatoes, with Rhizopus sp. being the most virulent. Cross-infection experiments revealed that the fungi could also infect other produce, with A. flavus causing the most severe rot on Alium cepa. This underscores the need for improved postharvest handling and preservation to reduce losses from mold infestation.