Effectiveness of storage facilities in managing toxigenic fungi and mycotoxins associated with stored maize (Zea mays L.) in Ethiopia

Abstract

Improved post-harvest handling of maize grain is an important activity to reduce fungal infection and mycotoxin contamination. This study aimed to evaluate the effectiveness of different storage facilities in managing toxigenic fungi and mycotoxins. The experiment was conducted from December 2020 to Augst 2021 at Jimma University with two storage types: storage bags (AgroZ®, fertilizer, jute, polypropylene, and PICS bag) for shelled maize, and Gombisa (traditional and modified) for maize cobs. Gombisa is cylindrical granary storage facility. Constant temperature and relative humidity were recorded in PICS, AgroZ®, and fertilizer bags, and consistent temperature in modified Gombisa. The toxigenic fungi detected in this study included Aspergillus, Fusarium and Penicillium species. Fungal infection incidence, grain germination and moisture content were highly significantly (P < 0.001) influenced by the interaction of storage facilities and duration of storage in both experiments. The highest incidences of toxigenic fungi were recorded in polypropylene and jute bags after 2nd and 4th months in the traditional Gombisa respectively. There was a significant positive correlation (P < 0.001) among storage duration and incidence of toxigenic fungi. Twenty-two mycotoxins were detected in the maize grains stored for eight months, with Fusarium metabolites being the most dominant. Fumonisins B1, B2, B3 and B4, and DON, ZEN and NIV were detected from loading time up to 8th month. Low fungal incidences, highest grain germination percentage, and low mycotoxin contamination were recorded in PICS, fertilizer bag and modified Gombisa. Thus, the study affirmed the effectiveness of PICS, fertilizer bags, and modified Gombisa in reducing mold and mycotoxin contamination under stored maize grain.