Today in Uganda, most farmers have adopted maize farming in that they need maximum profits from production, but to attain this a farmer should have maximum output possible of high quality from harvest.
Due to climatic changes and farmer negligence most, farmers have failed to maximise maize output of better grades from production.
There are many challenges alongside maize production which has hindered farmers from attaining maximum output possible as expected and they condemn themselves for their negligence on post-harvest handling.
This has attributed a lot to less kilogrammes sold and of poor quality every year, since grain is lost during machine threshing, transportation, rotting due to abrupt rainfall, sun-drying produce on bare grounds, poor storage, rodents attack, mold attack, weevil attack; resulting into poor produce hence low demand on market leading to un sudden changes in prices.
Maize being one of the staple foods grown and consumed by almost all Ugandan nationals, a worry on food security, standards of living, and wealthy have come up due to poor post-harvest handling which has resulted into mould growth, accumulation of dirt leading to rise on the level of aflatoxins beyond recommendation hence rejection on the East African market.
From the surveys and research, I have conducted, it was revealed that the most critical stage in maize crop value chain is post-harvest handling which has been the master key of Agriculture development because it’s the one which determines produce quality hence price.
According to Uganda bureau of statistics farmers in Uganda loses over 30% of the harvested crop every year due to poor post-harvest handling in terms of use of ineffective threshing machines resulting into gain cracking, poor storage facilities resulting into rodents’ attack, weevil attack, spillage during transportation, dirt accumulation during sun-drying hence an alarming percentage to the maize farmer since they get less than their expectation after selling.
It has been noticed that farmers are facing a lot of post-harvest challenges besides Government intervention to reduce post-harvest losses among maize farmers like the implementation of grain council, subsidies on post-harvest handling tools like tarpaulin, moisture meters, silos.
This is also due to limited awareness among rural farmers caused by unserious Agricultural officers on sensitising and guiding farmers on the proper use of agricultural inputs.
Post-harvest handling stage
This is the critical stage in maize production which farmers need to handle with much care since every mistake results in a loss.
The following are some of the mistakes farmers do at this stage in maize production leading to loses: –
Harvesting of immature grain, drying of grain on bare ground, use of an ineffective threshing machine, storing grain on ground in stores.
Storing of maize in damp conditions caused by leak proof roofs leading to mold growth, poor use of fumigants and insecticide resulting in contamination, storing of high moisture grain in silos hence attracts mold growth, shelling of immature grain resulting in cracking.
In order to reduce on the above mistakes’ farmers should know the following key things: –
How to manage maize before harvesting?
This is related to how best a farmer performs on the following pre-harvest activities especially on the amount of fertiliser to use, fertiliser, spacing, weeding, land preparation where by a better performance leads to a better result on grain produce.
The right harvesting equipment
This is related to the appearance of the tool in terms of sharpness, but most farmers use six-inch nails, knives to remove the cob from its husk on the maize plant.
So, every farmer should know the right harvesting tool to use in order to reduce grain damage through piecing the cob hence grain cracking contributes to post-harvest losses since the damages act as entry points for weevils.
The right time to harvest maize
Farmers should know that in Uganda there are different maize varieties with different gestation periods like Bazooka which matures at 145 days, longe 5 129 days, DK777 130 days.
A farmer has to know the variety he or she plants so as to reduce immature harvesting of maize which is one of the leading causes of post-harvest losses.
This has been known to shrink maize quality due to high rate of moisture loss hence reducing on the kilogrammes harvested and mould growth increasing on the level of aflatoxins.
How to effectively dry maize after harvest?
Maize should be well dried after harvest on tarpaulins to a level of 13% moisture content. This helps to reduce fungal infection hence prolonging the shelf life while maintaining high grade under storage.
How to store maize after harvest?
Farmer should keep in mind that before storing maize, his or her storage facility should have the following characteristics: –
Leak-proof roof, not allowing entry of water droplets from rainfall. Vermin proof, raised off the ground, crack free in that not allowing the hiding of storage pests. Others are pallets inside for putting on sacks and well ventilation.
Post-harvest handling activities
Transportation
This is associated with spillage of produce from the garden after harvest hence postharvest loss.
In order to reduce this farmer should be careful with who helps them in loading and unloading their produce from the garden to the stores since some workers are careless and do not bother about losses farmers encounter. The following are important to note while transportation of maize: –
Ensure the sacks carrying maize are clean, and the transporting media should be well disinfected with insecticide that are harmless to the users.
Always raise tarpaulin on rainy days upon transporting maize on a vehicle for a long distance. After harvest, transport maize immediately from the farm to drying and storage facilities.
Threshing /shelling
This is the removal of maize grain from its cob either by hand, motorised or pedal-operated shellers, or hand-operated shellers.
Motorised or pedal-operated sheller’s, are associated with maize cracking which reduces seed quality, grain loss through shattering into cob due to ineffective machine hence less kilogram.
To reduce this, farmers should choose the right machine from a trusted source to thresh their maize and farmers should shell maize when the moisture content is 13-14 %.
Importance of shelling
It allows farmers to effectively apply preservatives either organic like neem-based insecticide or inorganic insecticidal dust.
It reduces the volume of maize to be stored, and therefore requires smaller storage spaces. It reduces vulnerability to storage pests like the large grain borer.
Drying
This involves the removal of moisture from the harvested grain so as it can be stored. This is supposed to be done until maize measures 13-14% as it helps to reduce mould growth through rotting which is the key cause of increased levels of aflatoxins in grain hence reducing grain quality.
Key to note
Farmers should dry their produce on tarpaulins. Drying should be done during a sunny period for the case of natural drying.
Mechanical drying of machines that is to say driers should be under close supervision to prevent embryo damage due to too much heat.
Storage
This involves the act of keeping maize in stores before further processing into flour. The following are key to note before keeping maize: –
Store maize in hermetic storage units such as pic bags which are air tight bags so as to reduce on pest attack since it cuts off oxygen supply which gives them life.
Store maize in crack free rooms so as to avoid weevil attack since cracks act as hiding and breeding sites for weevils which damage maize grain.
Maize should be stocked when it’s properly dried with at least a moisture content of 13-14 %.
Storing the maize in areas with low relative humidity so as to prevent moisture damage. To make storage facilities stay dry requires logistical and operational expenses, but well worth the money because producers and traders can save much more in the long run by preventing post-harvest losses.
Ensure that storage bags in storage facilities are clean, dry, and piled on pallets which raises off ground. Ensure that bags are not in contact with contact walls.
This reduces rotting since maize tends to absorb moisture as it is hygroscopic in nature of which too much moisture attracts microbial growth hence rotting.
Challenges associated in reducing post-harvest losses in maize farming
Unpredictable weather during harvesting. Ineffective harvesting and drying equipment. Lack of knowledge on measuring or determining the right storage moisture content.
Farmers lack the equipment needed to test moisture content. Mould infestation on grains, and insects and rodents that feed on maize.
Farmers do not know how to identify grains infected with aflatoxins. Poor handling of maize, which results in grains shattering during transport.
Drying maize grains on bare ground exposes them to fungi, bacteria, and mold, resulting in losses.
Poor determination of maize agro-ecological zones i.e which maize variety performs best in a given zone either mid, lower or high altitude. High cost of post-harvest tools like tarpaulins, pic bags, mechanical driers.
Researched and written by Edson Kansime (Researcher, Senior Agricultural Extension Officer, Agribusiness Consultant and CEO at Royal Agro-Input suppliers Buhimba Shop.
