Actors’ post-harvest maize handling practices and allied mycoflora epidemiology in southwestern Ethiopia: Potential for mycotoxin-producing fungi management

Abstract

Maize plays a key role in household food security in Ethiopia, but its benefit has been limited with high post-harvest losses. This study was initiated to assess post-harvest practices and associated fungi pathogen epidemiology along the maize supply chain in southwestern Ethiopia. The study was conducted in five purposively selected districts and a three-stage sampling procedure was employed for selection of the target groups. In total, 342 participants from different actors were interviewed using a semi-structured questionnaire. Maize samples were collected every month from 63 randomly selected actors for mycological analysis during six months storage period. Post-harvest loss was estimated to be 31% and loss during storage was identified as a critical loss point. Comparing all biological agents, loss due to fungal pathogens in the store ranked on top. Moisture content at loading stage could not increase the shelf life of the commodity. Germination tests showed a significant (P < 0.01) decrease as storage duration increased, while mould incidence on cobs and kernels significantly (P < 0.05) increased. In total, seven fungal genera were isolated, characterized and identified, with Fusarium, Penicillium and Aspergillus being predominant. Most of the post-harvest practices are not effective in reducing post-harvest losses. Especially, farmers’ traditional storage structures can be influenced by external climatic conditions and make the grains liable to develop mould during the rainy season. This research, therefore, highlights the need to design, develop or modify existing storage technologies that reduce post-harvest loss due to mycotoxin-producing fungal pathogens. Furthermore, post-harvest drying to obtain optimum moisture content is also crucial to reduce losses.