Survey of Fungal Pathogens on Stored Sorghum (Sorghum bicolor) Grains in Yobe State, North East Nigeria

Sorghum (Sorghum bicolor) is the primary staple grain for the majority of rural households in Yobe State, and its storage over extended periods is a common food security strategy in the North East zone. However, grain quality deterioration due to fungal contamination in traditional storage structures represents an ongoing challenge. This study surveyed fungal pathogens associated with stored sorghum grains in traditional calabash, clay pot, and metal silo storage systems in four districts of Yobe State. Grain samples were collected from 60 households at three-month intervals over nine months. Fungal isolation, identification, and aflatoxin screening were conducted using standard mycological methods and high-performance liquid chromatography. Aspergillus flavus, Aspergillus fumigatus, Penicillium citrinum, and Fusarium moniliforme were identified as the dominant storage fungi. Total aflatoxin levels exceeded the maximum permissible limit of 20 micrograms per kilogram in 33 percent of tested samples after six months of storage. Storage in impermeable metal silos was associated with significantly lower fungal loads compared to clay and calabash containers. Moisture content at the time of storage was the strongest predictor of Aspergillus contamination. The study highlights the urgent need for community-level post-harvest education, safe storage technology promotion, and integration of grain quality testing into agricultural extension services in Yobe State. Keywords: sorghum, Aspergillus, aflatoxin, storage, Yobe State.