By Nelson Mandela Muhoozi
Minister of Agriculture, Animal Industry and Fisheries (MAAIF), guidelines on the post-harvest handling of grains like maize ensure food and nutrition security of all Ugandans and promotes increased incomes of households.
In addition, good post-harvest handling measures are key to reducing post-harvest losses of grains according to the ministry, and in addition increase food availability, reducing pressure on natural resources thus eliminating hunger while improving farmers’ livelihoods.
Tips on harvesting
Harvest maize when it is properly dry. This is only when the stalks and collar sheath have turned brown and the cobs are hanging downwards. At this stage, the moisture content will be between 17 to 20%.
During harvesting, use clean and dry harvesting tools and equipment such as carts, wheelbarrows, bags and baskets.
Prepare a clean, dry storage facility for the maize before shelling in the case of small scale farmers who don’t use modern harvesting equipment.
Deliver harvested maize immediately to clean and dry equipment for temporary storage before shelling.
Sorting, shelling, winnowing and grading of maize
Sort out maize cobs infested by insects, discoloured, moulded or physically damaged, from good maize.
Shelling maize
Shell maize using bare hands or proper equipment such as manual hand shellers or motorized shellers. And avoid shelling maize by beating with sticks as this damages the grains.
Drying maize
Dry grains on a clean concrete slab, or use plastic sheets or tarpaulins.
Farmers should avoid drying maize on bare ground as this will contaminate the grains with soils or dirt and further allow fungal or mould growth.
Dry the grains on open sunshine, maize cribs or any appropriate drying facility up to a moisture content of 13 to 14 percent.
Moisture content can be measured using a moisturemeter. However, for small scale farmers, moisture content can be determined using the following procedures;
Get a dry transparent glass bottle
Fill half the bottle with dry maize grains and add one spoonful of table salt
Shake well the mixture and observe the bottle, if the salt sticks onto the inner walls of the glass bottle, it means that the maize grains are not fully dried to the required moisture content.
Winnowing maize
Sort, sieve or winnow the grains to get rid of foreign matter and broken grains.
Grading maize
Separate maize grains according to size, colour and uniformity. Pack or bag the same size or uniform coloured grains in the same bags or store.
Storage of maize
Clean the facility properly before storage. A good storage facility should have the following;
It should be easy to clean
It should provide protection from rodents, birds and other animals
It should be water and moisture proof
It should be well aerated
It should protect the grains against variations of temperature and humidity
It should have a provision for periodic inspection where appropriate
It should be located away from possible sources of contamination such as animal and human waste, kilns, flour mills, bone-crashing mills, garbage rumps, tanneries, slaughter houses and chemical industries.
Other maize storage technologies that can be used include:
Hermetic bags: Maize grains can be stored in 80-100kg hermetic or airtight bags and stored under a vermin-proof facility. Place bags on pallets above the floor to avoid cold moist conditions that may lead to mould growth.
Use of smart metallic silos: Metal silos can also be used to store maize for a long time period (6 months and more).
Control of storage pests
Dry the maize properly up to 13.5 percent moisture content.
Store in rodent proof storage facilities, hermetic bags or smart metallic silos
Use modified environment (carbon dioxide and heat)
Use fumigants such as aluminum phosphide.
