When we eat boiled sweet potatoes, we might feel disappointed because peeling the potatoes can result in cutting off large pieces, leaving little to eat and sometimes a bitter taste. There are also times when the entire boiled sweet potato is not soft, remaining hard, making it inedible even after peeling. This type of sweet potato is what we are referring to.
Infested sweet potato.
The first type, infested sweet potatoes, are considered to be caused by pests, referred to as the “sweet potato pest” from abroad. After the sweet potato is damaged, small black spots gradually develop into larger round black dots with irregular patterns. When boiled, they remain hard and have a bitter taste, making them inedible, and if animals eat them, they can be poisoned. In severe cases, the disease spreads to the entire sweet potato vine.
The second type, waterlogged sweet potatoes, results from being soaked in water, also known as “hard-core” sweet potatoes. After being soaked, the sticky substance in the sweet potato’s structure that is not water-soluble increases, and the cell walls thicken. Once the threat of water is removed, that insoluble sticky substance does not diminish; moreover, the thickened cell walls do not thin out, ultimately forming a “barrier” against water, causing boiling water to create a repelling effect, resulting in waterlogged sweet potatoes.
Both types of infested sweet potatoes are inedible and cannot be used for propagation, severely impacting production. If, during storage, genuine sweet potatoes are mixed with the infested ones, it’s like “a worm spoiling the pot of soup”. One infested potato can ruin the delicious ones around it, causing significant losses.
Therefore, before storage, we must strictly select and discard any damaged sweet potatoes to prevent spreading the infestation to others.
