Effect of traditional and hermetic bag storage structures on fungus contamination of stored maize Grain (Zea mays L.) in Bako, Western Shoa, Ethiopia

The experiment was conducted between December 2017 and May 2018 at Bako, Ethiopia to study the effectiveness of traditional (Gombisa, Sack) and Hermetic bag storage structures and storage periods on fungal contamination of stored maize grain on agar plate method. The incidence and frequency of storage fungi was determined at 0, 2, 4 and 6 months of storage periods. The experiment was replicated three times in factorial design. The design was 3×4 in factorial fashion. The treatments were three storage types (Gombisa, sack and Hermetic bag), one variety of maize (Bako hybrid-661) and storage periods (0, 2, 4 and 6) months. The collected data were analyzed statistically using Generalized Linear Model (GLM) procedure of SAS and means that were significantly different were separated using Least Significant Difference (LSD). Fungi were the major causes of deterioration and quality loss on stored maize grains during the storage period. The fungal incidence and frequency significantly different (p<0.05) increased with storage periods. The highest (39.4%) Fusarium species incidence was recorded at the last six months of storage. Fusurium spp. occurred in Gombisa with the highest 29.9% incidence and 23% frequency, respectively. The highest frequency of Aspergillus species 26.7% was recorded in Gombisa whereas the minimum 18% was obtained from Hermetic bag in the six months of storage periods. In this study, Fusurium spp. was the most prevailing storage fungi followed by Aspergillus spp. As a result of this research, the Hermetic bag was determined to be more appropriate for protecting the stored maize grains from fungal attack during the storage periods and the stored grains have low fungal incidence and frequency until initial to four months. Therefore, gombisa and sack storages were inadequate for protecting stored maize from insect pests and fungal attacks. Overall, the hermetic bag storage can protect insect infestation and fungal development and consequently maintains seed viability and nutritional content during storage without use of insecticides.   Key words: Moisture, temperature, humidity, fungi, storage.