Maize stored in warehouses is highly susceptible to fungal colonization, with implications for food safety and aflatoxin exposure. This study evaluated the fungal load and species diversity of fungi isolated from stored maize harvested between 2021 and 2024 in Sokoto Metropolis, Nigeria. Fungal load declined from 2022 to 2024, with the highest load recorded in 2022 (5 × 10³ cfu) and the lowest in 2023–2024 (3 × 10³ cfu each), though this trend was not statistically significant (Spearman’s ρ = −0.866, p = 0.333). A total of 49 fungal isolates were identified, dominated by Aspergillus niger (38.78%), followed by Scopulariopsis candida (14.29%), Aspergillus flavus (12.24%), and Aspergillus oryzae (12.24%). Chi-square analysis revealed no significant association between fungal species distribution and harvest year (χ² = 13.96, df = 21, p = 0.871). Other isolates included Aspergillus fumigatus, Aspergillus parvisclerotigenus, Aspergillus aflatoxiformans, and Talaromyces islandicus. The predominance of Aspergillus species, particularly aflatoxigenic taxa, underscores the need for improved post-harvest storage practices and routine mycotoxin surveillance in northern Nigeria.

Keywords: stored maize; fungal load; Aspergillus spp.; Sokoto; mycotoxins; food safety.