Prevalence of Aspergillus flavus in maize-cultivated soils of Zanzibar

Abstract

Aspergillus flavus is known to infect maize while still in the field, resulting in contaminations that culminate into Aflatoxins in stored grains. Aflatoxins are reported to cause cancer, liver diseases, and death in humans. Determination of the levels of A. flavus in soils used for the production of maize in Zanzibar was still being determined despite the confirmed report on the occurrence of the contaminant in the soils. The present study quantified the A. flavus population in fields under maize cultivation in Zanzibar. The population of fungi isolates varied significantly (p<0.05) in different locations. Both A. flavus S-strain and L-strain were highly abundant in Bumbwisudi (5.767/g, 5.833/g) compared to other sites. They were lowest at Kiwani (0.567/g, 0.7/g) and Kibondeni (1.2/g, 0.867/g), A. niger was abundant at Kisauni (2.867/g) and lowest at Nyamazi (0.267/g) while A. parasiticus was abundant at Kisauni (2.633/g) and lowest at Mkokotoni (0.267/g). Fusarium spp. was highly abundant at Kitope (5.733/g) followed by Nyamazi (5.433/g), Mkokotoni (5.3/g), Bambi (5.267/g), Umbuji (5.2/g), Kisauni (5.133/g) while the lowest counts were at Bumbwisudi (0.7/g), Chimba (0.867/g), Kibondeni (1.133/g) and Kiwani (1.367/g). The results suggest that Aspergillus flavus will threaten maize production in Zanzibar.