Occurrence and Pathogenicity of fungi Associated with Tuber Spoilage: Evidence from Mubi Main Market, Adamawa State, Nigeria

 Tubers are relatively inexpensive, nutritionally rich staple foods widely consumed across Nigeria, but their availability throughout the year is constrained by short shelf life, largely due to fungal post-harvest rots. This study investigated the fungi responsible for tuber spoilage in Mubi main market, Adamawa State. Twenty tubers (five each of cocoyam, Irish potato, white yam, and sweet potato) were sampled, and fungal isolates were identified using standard mycological techniques. Pathogenicity tests were performed to assess their virulence. A total of 28 isolates, belonging to three genera and six species, were recovered: Fusarium oxysporum, Aspergillus flavus, Aspergillus niger, Rhizopus stolonifer, Aspergillus parasiticus, and Aspergillus tamari. Rhizopus stolonifer (32.1%) was the most frequently encountered followed by F. oxysporum (25.0%), whereas A. flavus (3.6%) was the least common. Irish potato recorded the highest fungal contamination (32.1%), while white yam had the lowest (10.7%). Species distribution showed F. oxysporum and A. flavus associated with white yam rot, R. stolonifer and A. parasiticus with sweet potato rot, A. tamari and R. stolonifer with Irish potato rot, and F. oxysporum and A. niger with cocoyam rot. Pathogenicity assays showed varying rot patterns, including dry rot, soft rot, and wet rot, with tuber weight losses ranging from 75.7–100%. The most severe cases occurred with A. parasiticus on sweet potatoes (100%) and F. oxysporum on white yams (91.4%). These findings confirm that fungal colonization is a major cause of post-harvest spoilage in tubers, reducing food availability, decreasing market value, and posing potential public health risks through mycotoxin production.