Dynamics of Fusarium and fumonisins in maize during storage – A case of the traditional storage structures commonly used in Uganda

The dynamics of Fusarium and fumonisins in maize grains stored in traditional structures (Granary, Mudsilo and Tua) commonly used in Uganda were investigated. The storage structures were constructed using locally available materials following the procedures used by farmers. Maize was stored in both shelled and unshelled form. Moisture and insect damage were also monitored. Moisture content of the maize grains in all the storage structures decreased from an average of 19.2% to <14% within two months. The maize weevil (Stophilus zeamais) was the major cause of grain damage. Fusarium incidence in all the structures increased from an average of 61.9–77.5% in the first 2 months of storage and thereafter significantly decreased (p < 0.05) to 31.9% by the sixth month. The storage structures did not significantly affect (p > 0.05) Fusarium incidence at each sampling stage. Fumonisin levels in all the storage structures decreased over the storage period from an average of 5.7 to 2.8 mg kg−1. After 6 months, maize grains from the Granary had significantly lower (p < 0.001) fumonisin levels (1.61 mg kg−1) compared to that from Tua (3.4 mg kg−1) and Mudsilo (3.5 mg kg−1). These findings present an affordable handling practice for reducing the health hazards associated with fumonisin exposure amongst maize consumers. Good maintenance of storage structures to ensure that the moisture content of the grains remains below 14% throughout the storage period is emphasized.