What are the control methods for sweet potato soft rot?

1. Harvest at the right time and avoid mechanical injury. Summer sweet potatoes should be harvested completely around the time of Frost's Descent, and autumn sweet potatoes should be harvested completely before the Start of Winter. Choose a sunny day for harvesting, and when digging the potatoes, minimize or avoid causing wounds.

2. Select healthy potatoes carefully to ensure safe storage in the cellar. Before the sweet potatoes are put into the cellar, they must be carefully selected, and diseased, damaged and rotten potatoes must be discarded. After the surface moisture has dried, put them into the cellar, and use a new cellar if possible. Before using an old cellar, remove the old soil inside the cellar to expose fresh soil, or use 15 grams of sulfur per sq m for fumigation, disinfection and sterilization.

3. Strengthen management: reduce humidity, keep warm and ventilate.

(1) In the early storage period, that is, within 30 days after being put into the cellar, the main work during this period is ventilation, heat preservation and moisture removal. Keep the temperature below 15°C and the humidity at 90%-95%. Use ventilation holes or doors and windows, and where conditions permit, use exhaust fans to strengthen ventilation. If the daytime temperature is high, you can adopt the method of opening at night and closing during the day; later, as the temperature gradually drops, the ventilation holes can be opened during the day and closed at night. When the cellar temperature stabilizes below 15°C, ventilation can be stopped.

(2) In the middle storage period, that is, the period after the early stage until the Start of Spring, the cellar temperature drops, and this is the period when potato tubers are most susceptible to cold injury. Keeping warm and preventing cold is the focus of work during this period, so that the cellar temperature is not lower than 10°C, and is best controlled at 12°C-14°C. Seal the ventilation holes or doors and windows, thicken the insulation layer outside the cellar, and cover the potato pile with straw mats or soft grass.

(3) In the late storage period, that is, after the beginning of spring (March), when the outside temperature gradually rises, check the cellar temperature frequently and keep it at 10°C-14°C. If the temperature is too high at noon, ventilate promptly, and close the vents promptly in the evening so that the cellar temperature remains within the suitable range.