Sweet Potato Storage Tips: Keep These Methods in Mind

1. Types of storage cellars: Sweet potatoes are stored in vertical shaft cellars, which are generally 4.5 -5 m deep, with a soil layer 2.5 -3 m thick above the cellar chamber.

2. Disinfection of the storage cellar: Store seed potatoes in a sterile cellar; it is best to use a new cellar. If an old cellar is used, scrape 3 -4 cm off the walls and floor to expose fresh soil, spread a layer of fine sand on the cellar floor, then fumigate with sulfur at 15 g /m3 for 1-2 days. Open the cellar entrance and after 7 days select the potatoes for storage.

3. Putting into the cellar: (1) Careful selection. The potato pieces put into the cellar should be short, spindle-shaped or oval, and meet the “seven noes” standard, namely no disease spots, no insect holes, no grooves, (shallow grooves), no damage, no green exposure, no freezing, and no water soaking. A tuber weight of 400 -800 g is best. Oversized and undersized tubers should be stored separately for other uses. (2) Chemical treatment. Dipping: At sweet potato harvest, dip the potatoes in a 800-fold solution of 70% (pure) thiophanate-methyl; depending on the weather, dry the potato skin before putting them into the cellar. Spraying: After the sweet potatoes are dug, stack them in rows and spray with a 800-fold solution of 70% (pure) thiophanate-methyl, spraying as evenly as possible; depending on the weather, dry the potato skin before putting them into the cellar. (3) Putting into the cellar by category. When putting them into the cellar, also follow the “three separations”: separate spring and summer potatoes; separate different types (for example, separate tubers of different colors such as flesh-colored, yellow, red, white, and purple); separate medium and large tubers (< 500 g is medium, ≥ 500 g is large) to facilitate classified packaging and sale. The potato pile should be at least 20 cm away from the cellar walls. (4) Storage amount. The storage amount of fresh potatoes should be determined by the size of the cellar, and generally should account for about 2/3 of the entire cellar volume.

4. Cellar management. The suitable temperature for sweet potato storage is 10℃ - 15℃ , and the relative air humidity is 85%-95%. (1) Early storage period. Within 7 days after the tubers are put into the cellar, keep the cellar temperature at about 20℃ , which helps the wounds heal. After 7 days, open the cellar entrance for ventilation to lower the temperature and remove moisture, so that the cellar temperature does not exceed 15℃ . When the cellar temperature naturally drops to 14 -15℃ , seal the cellar. (2) Mid storage period. During this period, the cellar temperature should be kept at 12 -14℃ . When the cellar temperature stabilizes at 14℃ , the cellar entrance can be sealed; for shallow cellars with a relatively thin soil cover on top, add soil cover, using a method of one layer of straw and one layer of soil to keep warm and prevent cold. (3) Late storage period. During this period, keep the cellar temperature at 11 -13℃ . When the air temperature rises to 11℃ , open the cellar entrance and ventilation holes for air exchange, and enter the cellar for inspection. If individual rotting potatoes are found in the pile, remove the rotten potatoes and continue storage; if there are many rotten potatoes inside and outside the pile and storage cannot continue, sell them as early as possible.