Farmers work hardest on production and lose a great deal after it. Post-harvest losses are also the cheapest losses to fix, because the crop already exists and no additional land, seed or labour is required.
Harvest at the right moisture
Harvesting too early means grain that will not store. Too late means losses to birds, rodents, insects and shattering, and grain already damaged in the field.
For maize, wait until the cobs have dried down on the plant and the husks have turned. A practical field test is the thumbnail: mature, sufficiently dry grain resists a nail impression.
Dry properly, off the ground
Drying on bare ground is the most damaging common practice. It picks up soil, stones and animal waste, absorbs moisture back from the ground, and exposes the crop to contamination.
- Dry on a raised rack, a clean tarpaulin, or a concrete slab.
- Spread thinly and turn several times a day.
- Cover at night and at any sign of rain. Grain that gets damp overnight and dries again is at high risk of mould.
- Continue until properly dry. Grain bitten between the teeth should crack sharply, not squash.
Why moisture matters so much
Grain stored above safe moisture will develop mould, including aflatoxin-producing species. Aflatoxin is invisible, is not destroyed by cooking, is a genuine health risk with long-term exposure, and will cause the crop to be rejected by any formal buyer who tests.
The habit that most reduces this risk is simple: never store grain you are not confident is dry, and never let drying grain get rained on and then bag it.
Clean and sort before storage
Remove broken grain, chaff, stones and any discoloured or mouldy kernels. Damaged grain is where insects begin, and mouldy grain contaminates the rest. Sorting also raises the price, because buyers discount for foreign matter.
Storage
- Hermetic bags are the most effective affordable option. Sealed airtight, they suffocate insects without chemicals and hold moisture out. Only effective if the grain was dry when bagged and the bag is sealed properly and not punctured.
- Metal silos are excellent and long-lived where affordable.
- Traditional granaries work if raised off the ground, rodent-proofed, and kept dry and ventilated.
- Ordinary sacks in the house are the most common and the most vulnerable.
Store on pallets or poles, never directly on the floor, and keep bags away from walls so air moves and damp does not transfer.
Pests
The larger grain borer and weevils cause most storage loss. Clean the store before harvest, remove all old grain, and never store new grain on top of last season's. Hermetic storage handles most insect problems without chemicals. If using a storage chemical, use only a product registered for grain, at the stated rate, and observe the withholding period.
Check the store
Inspect monthly. Look for insects, smell for mustiness, and feel for warmth in the bag, which signals moisture and biological activity. A store checked monthly loses far less than one opened when the grain is needed.
Should I sell at harvest or store?
Prices are usually lowest at harvest, when everyone sells, and higher later. Storing to sell later is the most reliable price gain available to a smallholder, but only if the grain survives storage in good condition. Storing badly and selling mouldy grain at a discount is worse than selling immediately.
The honest sequence is: fix drying and storage first, then use storage as a price strategy.
Working as a group
Bulk storage and bulk sale give a group better prices and make a shared drying slab or a set of hermetic bags affordable. It requires an agreed quality standard at intake, since one member's damp maize will spoil a shared store.