How to Store and Keep Sweet Potatoes Fresh? A Detailed Explanation of Practical Technical Points

I. Building the sweet potato cellar The cellar site should generally be chosen at a corner of the courtyard, with a cellar hole dug 3-5 m deep, the mouth of the hole about 80 cm in diameter, and at the bottom 2-3 storage chambers dug to the side, each 1.7 m high, 1.4 m wide and 3 m deep. If it is an old cellar, the loose soil on the cellar walls needs to be scraped off, and then a fungicide should be sprayed to prepare it for storing the sweet potatoes.

II. Preparation before storage and harvesting techniques After Frost's Descent, it is time to harvest sweet potatoes. Harvest should be done on a clear, windless day, taking care to dig, handle and transport gently, and to prevent digging injuries, bump injuries and breakage as much as possible. After transporting them back, place them in a shady spot in the courtyard and dry the skin. If there are damaged tubers, they should be placed in the sun to dry for 2 days, so the wounds dry and harden and bacterial infection is prevented. If rainy weather occurs, cover them with plastic sheeting to protect them from rain. It is best to spray them carefully once with 800-fold carbendazim or 1000-fold thiophanate-methyl solution, let them dry after spraying, and then handle them gently when putting them into the cellar. The potato pile should occupy about 50% of the storage chamber, to maintain proper air flow and help remove the carbon dioxide released by the respiration of the tubers. Store good tubers separately from injured ones; tubers with diseased scars must not be put into the cellar, to prevent infection by pathogens. Frozen tubers also must not be put into the cellar.

III. Management work after storage (1) Temperature management Sweet potatoes begin to sprout above 15°C, and under high-temperature conditions they are prone to disease; below 10°C they are susceptible to freezing injury, and frozen tubers are easily infected and rotted by soft rot bacteria. Therefore, the suitable temperature for storing sweet potatoes is 10°C-15°C. A thermometer can be used to measure the cellar temperature and the temperature of the potato pile; according to the temperature conditions, increase or decrease the covering material, and measures such as sealing the cellar to keep it warm or opening the cellar to release heat can also be used to regulate the cellar temperature. (2) Humidity management After the tubers are put into the cellar, the relative humidity inside the cellar is required to remain stable at 80%-90%. If the relative humidity is too low, the tubers are prone to water loss and shrinkage; if the humidity is too high, the tubers are prone to rot, so timely adjustment should be made. When the humidity is too low, clean cold water should be sprinkled on the tubers; when the humidity is too high, ventilation and air release should be carried out to lower the humidity. Check the temperature, humidity and condition of the potato pile once every 10 days, and if rotten tubers are found, pick them out promptly.

IV. Points for attention (1) No alcohol. People who have drunk alcohol must not enter the cellar, because alcohol will accelerate the rotting of the tubers. (2) Do not place other fruits and miscellaneous items, to prevent contamination by pathogens.