Curing extends potato shelf-life to 40 days

Farmers can increase the shelf-life of sweet and Irish potatoes, and other root crops to more than a month by curing their produce before and after harvest.

Curing, which is cost-free, involves the removal of foliage some days before harvest, and storing root tubers in appropriate conditions after harvesting.

This boosts the shelf-life from between three and 10 days to 40 days, allowing for access to distant markets.

A two-year research by Nairobi-based International Potato Centre, which involved three tests in various seasons, established that the removal of sweet potato foliage between two and four days before harvesting extends their durability.

“The results have proved that in-ground curing gives a pleasing appearance and taste when cooked after 40 days since harvest whilst uncured ones were completely shriveled,” the study reads.

The process heals minor wounds in the outer layer of tubers, protecting them against diseases and reducing shrinkage. This, extends storage time because helps strengthening of the skin.

Better results are realised when the sweet or Irish potatoes are kept at temperatures between 25 degrees Celsius and 30 degree Celsius.

“Fresh roots have a high respiratory rate and can be damaged by cuts and bruises during harvesting and post-harvest handling. The cuts and abrasions become entry points for micro-organisms and moisture loss and subsequent weight loss,” the study says.

Similarly, storing the tubers in dry sand for 60 days without prior removal of leaves before harvest maintained good quality and less weevil infestation.

The potatoes lost weight of between 7 per cent and 24 per cent while those left in the open lost up to 75 per cent.

Three days in-ground curing led to least weight loss of 17 per cent.

Kenya is a tropical country where Irish and sweet potato farming is done in relatively low temperatures and humidity.

Room temperature range from 20 degrees Celsius to 25 degrees Celsius potato.

With Irish potato is considered the second most staple food and a cash crop for more others. Sweet and Irish potatoes are mostly sourced from western, central, Rift Valley, among others.

Accessing main roads for transport to town markets, such as Nairobi and Mombasa, remains a challenge because of poor roads. More produce goes to waste more-so when it rains and roads are impassible.

Embracing these cost-free techniques can cushion themselves against post-harvest losses and give them more time to access markets.

The study was done in Uganda's Mukono, Rakai and Masaka Districts. Improved variety, Kabode, Vita and local varieties selected by farmers were used.

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