08/05/2025
*UNDERSTANDING CASSAVA QUALITY DECLINE DURING THE RAINY SEASON*
During the intense rainy season, usually around the months of May to July in the South West region of Nigeria, farmers and processors need to be very observant and cautious. At this time of the year, it is often noticed that cassava plants which are already mature begin to produce fresh green leaves again. The farm becomes more lush and visually appealing, giving an impression of vitality and growth. However, behind this outward greenness lies a serious physiological signal that should not be ignored.
When cassava reaches nine to ten months or even more, and the rains become consistent and heavy, the plant reacts to the abundant moisture by resuming vegetative growth. This is a natural response, but one that carries certain risks, especially for the quality of the tubers that lie beneath the soil.
While it may appear that the tubers are increasing in size and bulk during this time, what is actually happening underground could be a silent loss. The starch content and dry matter, which are the real economic values of cassava, begin to deplete rapidly when tubers remain too long in water-saturated soils. Even when physical rottenness does not occur, the quality of the tubers begins to decline.
Tubers that once promised good processing yield for garri, starch, flour or fufu may start to give disappointing results. They become more fibrous, and when processed, they produce less output. The waste increases, and the final products lose their visual appeal. Instead of the expected bright white or creamy colour that good cassava products are known for, the resulting garri or fufu comes out dull, off-colour, and unattractive.
For fufu in particular, the low starch content affects its cooking performance. It does not stretch or bind well, and this reduces its market value.
Processors should therefore be more discerning during this critical season. Cassava bought during heavy rains may not yield as much as expected. A truckload of cassava tubers that used to give ten bags of fermented white garri—each bag weighing about fifty to fifty-five kilograms or containing twenty-two custard rubbers—may now yield only eight or eight and a half bags.
The situation with fufu is often worse. It is not just about the reduced quantity, but also the poor colour, low plasticity and general unattractiveness of the final product. Buyers will notice these defects and reject such products or offer very low prices.
Farmers too must understand that while the tubers may look bigger from the outside, this could be misleading. Without timely harvest, they may unknowingly lose a large portion of their yield to underground deterioration. In some cases, up to half of the actual value may have been lost before the harvest is done. Even when the tubers are not visibly rotten, their value in terms of starch and dry matter would have dropped significantly.
There are varieties of cassava, both local and improved, that have some resistance to rot, but this does not mean that they are immune to quality loss. Once they remain unharvested in wet conditions for too long, the same depletion of starch and dry matter occurs. The tubers become more fibrous and less useful for processing.
Therefore, the best approach is to plan the planting time in such a way that maturity does not coincide with the peak of the rainy season. For those who intend to allow cassava to remain in the soil for a longer period, especially beyond twelve months, late planting is advisable.
Planting done in late October or early November will allow for harvest between January and March of the upper year, when rainfall is minimal and the soil is more stable. This helps to preserve the starch content and maintain the overall quality of the tubers.
In all, cassava farming and processing during the rainy season requires both awareness and timely decision-making. What appears to be a thriving field of green may in fact be a signal that harvest should not be delayed any further. Paying attention to these changes can save farmers and processors from significant economic losses and help maintain the quality that markets demand.
Let timing work in your favour, not against your efforts.
