Abstract
A gombisa is a traditional Ethiopian structure widely used for maize storage over several months. It lacks adequate ventilation for timely moisture removal, which promotes mold development and aflatoxin production. In this study, a traditional gombisa was compared to one modified by installing a solar powered fan to provide forced ambient air ventilation during daytime. Approximately 900 kg of moist ear maize were loaded into each structure and samples from selected locations were weighed periodically to monitor moisture loss. Temperature and relative humidity of ambient air and inside the maize bulk were continuously recorded. Significantly faster drying was achieved in the modified gombisa, where drying occurred from bottom to top. In the traditional store, drying was much faster at the surface, with drying rate declining sharply with increasing depth in the bulk due to more limited air exchange. Relative humidity in the bulk center of the traditional structure remained above 90% for more than 4 weeks while in the modified gombisa it decreased progressively from the beginning of the trial. The results are promising and the modifications simple to implement, with the potential to effectively reduce post-harvest losses of maize. Field tests in Ethiopia are recommended.
Highlights
Maize is one of the most important staple foods in several African countries
Maize is very susceptible to aflatoxin contamination and this together with its high consumption in many African countries result in chronic exposure, often starting before b irth[10]
Farmers often delay harvest for several weeks and let the crop dry in the field, exacerbating mold contamination and aflatoxin production due to increased insect infestation and damage, but still, a safe moisture content below 15% is seldom a chieved[12]
Summary
Maize is one of the most important staple foods in several African countries. In 2016 Ethiopia produced 7.84 Mt of maize and 8.11 Mt are estimated to have been produced in 2 0171. Humid climates, the traditional methods used by farmers for drying grain rely on natural air movement to reduce moisture content to a safe level for storage. They may utilize the extra drying capacity. A further modification to a traditional granary, proposed in this study, is to use a low power, photovoltaic driven fan to force ambient air during daytime hours when air temperature rises and relative humidity drops, expediting drying and potentially allowing the storage of maize harvested at higher moisture content shortly after reaching maturity
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call