Control of soft rot of sweet potato

First, timely harvest to avoid mechanical injury. Summer potatoes should be harvested before and after Frosts Descent, autumn potatoes should be harvested before the Beginning of Winter, harvest in sunny days should be chosen, and wounds should be minimized or avoided when digging potatoes.

Second, select healthy potatoes to ensure safe entry into the cellar. Before entering the cellar, sweet potatoes should be selected, disease, residual and rotten potatoes should be eliminated, steam should be dried into the cellar, and new cellar should be used as far as possible. Before using the old cellar, the old soil in the cellar should be eradicated to reveal new soil, and 15 grams of sulfur can be used for fumigation and sterilization per square meter.

Third, strengthen management, reduce humidity, heat preservation and ventilation.

(1) in the early stage of storage, that is, within 30 days after entering the cellar, the main work of this period is ventilation, heat preservation and moisture dissipation, with the temperature controlled below 15 ℃ and the humidity controlled at 90% to 95%. The use of ventilation holes or doors and windows, conditional use of exhaust fans to enhance ventilation. If the temperature is high during the day, it can be opened at night and closed during the day; later, with the gradual decrease of the temperature, the vents can be opened and closed day and night, and there will be no ventilation when the pit temperature is stable below 15 ℃.

(2) during the middle period of storage, that is, from the early stage to the Beginning of Spring, the pit temperature decreased, which was the period when the potato was most vulnerable to cold injury. Heat preservation and cold prevention was the focus of work in this period, so that the pit temperature was not lower than 10 ℃, and it was best to control it at 12 ℃ ~ 14 ℃. Close the ventilation holes or doors and windows, thicken the insulation layer outside the pit, and cover the potato pile with straw mat or soft grass.

(3) in the later stage of storage, that is, after the beginning of spring (March), the external air temperature gradually rises, the pit temperature should be kept at 10 ℃ ~ 14 ℃, the air temperature should be released if the temperature is too high at noon, and the tuyere should be closed in the evening to keep the pit temperature within the suitable range.