Post-harvest management is one of the most critical stages in maize production. Many farmers work hard throughout the growing season but lose a significant percentage of their harvest due to poor drying, improper storage, fungal contamination, or pest damage. In some regions, post-harvest losses can reach 20–40% if proper measures are not followed.
Post-harvest practices begin immediately after harvesting and continue until the maize reaches the final consumer. These practices include drying, shelling, cleaning, grading, storage, pest control, and processing. Proper management ensures food safety, maintains grain quality, preserves seed viability, and increases market value.
Drying is the most important post-harvest activity. Freshly harvested maize usually contains 20–30% moisture content. If stored at this moisture level, fungi will rapidly grow, leading to mold development and aflatoxin contamination.
The safe moisture content for long-term storage is 12–13%. For seed maize, even lower moisture may be required to maintain viability.
Sun drying is the most common method used by small-scale farmers. Maize cobs or shelled grain are spread on clean tarpaulins, raised platforms, or concrete surfaces to prevent contamination from soil.
Commercial farmers often use mechanical dryers that blow heated air through grain. These systems allow controlled drying regardless of weather conditions. However, temperatures must be carefully managed to avoid damaging grain quality.
Shelling is the process of removing grains from maize cobs. It can be done manually or using mechanical shellers. Manual shelling is labor-intensive but suitable for small farms. Mechanical shellers increase efficiency and reduce grain damage when properly adjusted.
After shelling, maize should be cleaned to remove:
Storage protects maize from moisture, insects, rodents and fungal contamination. The choice of storage method depends on farm size, climate and available resources.
Traditional raised granaries allow air circulation and reduce moisture buildup. However, they must be well maintained to prevent rodent entry.
Hermetic bags create an airtight environment that reduces oxygen levels, killing storage pests without chemicals. These bags are highly effective and increasingly popular worldwide.
Metal silos provide long-term protection against insects and rodents. They are ideal for commercial farming operations and can store large volumes safely.
Aflatoxin is a toxic substance produced by certain fungi such as Aspergillus species. It develops when maize is stored with high moisture or when grains are damaged. Aflatoxin contamination is dangerous to both humans and livestock and can make maize unsellable.
Even after proper drying, maize remains vulnerable to storage pests such as:
Pest control methods include hermetic storage, botanical pesticides, approved grain protectants, and maintaining clean storage facilities.