Effect of Environmental Factors on the Growth of Aspergillus Species Associated with Stored Millet Grains in Sokoto.

Fungi constitute a major problem in the storage of agricultural products especially cereals. In the present study, the effects of light, relative humidity and temperature on the growth of Aspergillus species (Aspergillus candidus, A. flavus, A. fumigatus, A. niger and A.oryzae) associated with stored millet grains were investigated. Light stimulus had no significant effect on the mycelial growth of the fungi. Of the relative humidity regimes tested, 85% and 100% were the most favourable for the growth of Aspergillus species. Growth was generally poor at 32.5 and 50.5% relative humidities. There were significant (p < 0.05) differences in the growth of Aspergillus species with respect to temperature regimes. Generally, high growth was obtained under incubation temperatures of 30°C and 35°C. Cereals in general and millet grains in particular exposed to high humidity and temperature range of 30°C and 35°C may be susceptible to contamination by Aspergillus species.