Last updated on October 30th, 2026 at 10:33 am
Cassava post-harvest losses begin the moment a root leaves the soil, and they continue right through processing, transport, and market. Some losses are physical, with roots rotting, while others hide in bitter garri and prices that collapse during a glut.
I have never lost a harvest of roots to spoilage, and the reason is simple: we harvest only what we can process.
That batch habit, common across Ngwa and neighboring towns in Abia State, is the oldest loss-prevention method my community knows.
This article explains exactly where losses happen along the value chain, with stage-by-stage figures from Nigerian surveys.
It shows why quality and price losses can cost more than rotten roots, and how village tools changed results in my community.
Practical steps for farmers, processors, and policymakers close the guide, with links to detailed handling, drying, and processing advice.
Table of Contents
What Counts as a Post-Harvest Loss?
A post-harvest loss is any drop in the quantity or value of cassava between harvest and the final buyer.
Physical losses include roots that rot, tubers sorted out as too small or woody, and product spilled or spoiled.
Quality losses are quieter, such as bitter garri, discolored flour, or roots that cook poorly after deterioration sets in.
Economic losses follow when buyers pay less for older roots or when a glut drives prices below production costs.
Where Cassava Post-Harvest Losses Happen in Nigeria
GIZ surveys of Nigerian value chains, summarized in Rural 21, measured losses at each stage.
| Stage | Share lost | Main cause |
|---|---|---|
| Harvest and farm storage | Up to 6.6 percent of fresh roots | Damage and delays before processing |
| On-farm garri processing | 8 percent | Handling and processing losses |
| Commercial garri processing | 14.4 percent | Sorting out roots too small or too woody |
| Starch production and storage | 11.8 percent | Processing and storage losses |
The same report estimated Nigeria loses over 6.3 million tonnes of fresh roots a year, worth about 686 million euros.
Transport of garri was also named as a major loss point, though the surveys gave no separate figure.
Why Roots Spoil So Quickly
Roots kept outside warm, humid wound-healing conditions usually become unacceptable within two to three days, according to FAO’s chapter on deterioration losses.
Damaged roots take longer to cook, taste bitter, and give garri that swells poorly, the same chapter notes.
In my community, garri made from roots held until the fourth day tastes bitter or strange because fermentation has gone too far.
Dry-season harvesting adds to the risk, because hard soil forces hoe digging that bruises roots by mistake.
Step-by-step methods for lifting, moving, and checking roots are covered in the guide to post-harvest handling of cassava.
Hidden Losses: Quality and Price
FAO’s review found that price cuts for poor-quality roots may cost farmers more than roots physically thrown away.
In Ghanaian markets studied by FAO, older cassava sold at discounts ranging from about 25 to 79 percent.
Gluts create a different price loss, and garri prices fell 51 percent year on year in late 2025, BusinessDay reported.
Farmers in my area felt the 2023 glut directly, selling roots at a loss because nearby processors could not absorb them.
How surpluses crash prices, and how processing protects farmers, is set out in the cassava glut explainer.
Rainy-season chips add another loss, since sun-dried slices frequently turn moldy, brown, or black before they dry.
How Ntigha Keeps Losses Low
Harvest in Batches
Families harvest only the roots they can peel and press the next day, then return to the farm later.
Even my flour and starch business follows that rule, harvesting small batches rather than clearing a plot at once.
People who buy a standing farm for garri, akpu, or a burial or wedding do the same.
From Bamboo Poles to Screw Presses
When I was young, grated mash was pressed with four bamboo poles, a chain loop, and a strong rope.
Two or three people tightened the poles around the sack of mash, then left it dripping overnight.
Since the 1990s, a hand-turned screw press has made that step easier, faster, and far more efficient.
Screw press designs used around Ntigha are compared in the guide to the cassava pressing machine.
Graters That Come to the House
Peeling is still done with knives, but grating moved to machines long ago.
Some neighbors own fixed graters that people visit, while mobile graters on tires come to the house, grind the roots, and leave.
That service lets families process a batch within a day without buying a machine, as the guide to the cassava grinding machine explains.
Roasting still happens in wide local pots, following the traditional garri processing steps passed down through families.
Practical Ways to Cut Losses
- Farmers: harvest in batches, lift roots when soil is moist, and process within a day of harvest.
- Processors: sort roots on arrival, process damaged roots first, and dry surplus roots into chips under controlled heat.
- Traders: move roots in the shade, handle bags gently, and sell fresh roots within two days.
- Cooperatives: share graters, presses, and dryers so members never wait days for equipment.
- Policymakers: improve rural roads, power for dryers, and access to processors that can absorb harvest peaks.
Drying methods that save surplus roots are compared in the guide to cassava drying techniques.
Dried slices can then feed flour, feed, or export markets, as the article on cassava chips and pellets shows.
Wider barriers, from roads to finance, appear in the overview of cassava value chain challenges.
Conclusion
Cassava post-harvest losses come from rotting roots, rejected tubers, bitter products, and prices that fall during gluts.
Nigerian surveys put losses at up to 6.6 percent on the farm and 14.4 percent in commercial garri processing.
Families in Ntigha avoid physical losses by harvesting in batches and processing within a day.
Screw presses since the 1990s and mobile graters made that rhythm much easier.
Better roads, dryers, and nearby processors would protect prices during gluts too.
For training on handling and processing, contact Cassava Pathway through this website or WhatsApp.
Frequently Asked Questions
What are cassava post-harvest losses?
They are drops in the quantity or value of cassava between harvest and sale.
Examples include rotting roots, rejected tubers, bitter garri, and lower prices for older roots.
How much cassava is lost after harvest in Nigeria?
GIZ surveys found farm losses up to 6.6 percent and commercial garri losses of 14.4 percent.
Total yearly losses topped 6.3 million tonnes of fresh roots across Nigeria.
Why does cassava spoil so quickly after harvest?
Fresh roots can begin deteriorating within a day, and damaged roots spoil the fastest.
Without warm, humid wound-healing conditions, most roots become unacceptable within two to three days.
How can farmers reduce cassava losses?
Harvest only what you can process next day, lift roots gently, and keep them shaded.
Dry any surplus into chips under controlled heat instead of letting roots rot.
Chimeremeze Emeh is a tropical crop farmer and chemical engineer from Ntigha, Isiala Ngwa North LGA, Abia State, Eastern Nigeria, specializing in cassava and palm oil, with over 30 years of hands-on experience growing, harvesting, and processing cassava. He grows TMS series, TME 419, and local traditional varieties on his own farms and operates a small-scale cassava flour and starch production business through Cassava Pathway, which he founded as a CAMA-registered agribusiness in 2024. He is also the founder of Palm Oil Pathway, where he applies the same tropical farming expertise. His farms are located in Ntigha, Abia State.