Four key points of timely harvest of sweet potatoes

The suitable harvest time of sweet potato should be determined according to climatic conditions, safe storage time and the arrangement of the next crop. However, if the harvest is too early, the yield of sweet potato will be significantly reduced; if the harvest is too late, the sweet potato is often affected by low temperature and cold injury, so it is not tolerant to storage and the cutting and drying rate decreases. Therefore, when harvesting, we should pay attention to the four key points of "land", "soil", "retention" and "use". "Land" is harvested according to the ground temperature. When the ground temperature is about 18 ℃, the weight of sweet potato increases little; when the ground temperature is about 15 ℃, the sweet potato stops expanding; when the ground temperature is below 9 ℃ for a long time, chilling injury will occur. Therefore, sweet potatoes are generally harvested when the ground temperature is 18 ℃ and finished before dry frost. Spring sweet potatoes for dry cutting or winter wheat for stubble are generally harvested in front of Cold Dew, summer sweet potatoes for seed use are harvested in front of Frosts Descent, and sweet potatoes for storage and consumption are harvested later, but they must be harvested before frost. "soil" is harvested according to the dry and wet soil. Too dry or too wet soil is disadvantageous to sweet potato harvest. When the soil is too dry, the soil water content decreases and the soil temperature changes greatly, so the sweet potato is vulnerable to cold damage and is not easy to harvest. Too wet, too much soil water content, sweet potato is not only not easy to harvest, but also has high water content and is not resistant to storage after harvest. When the soil is too wet, you should first cut off the sweet potato stems, bask in the sun for a few days, and wait for the soil to dry before harvesting. To "stay" is to harvest according to whether you leave seeds or not. Summer sweet potatoes for seed use should be harvested in the morning on a sunny day, bask in the field, enter the cellar in the afternoon, and do not spend the night in the field to avoid cold damage. "use" means to store according to the purpose. After the sweet potato is harvested and planed, the sweet potato can be selected in the field, the sick, residual and water-stained potato pieces can be removed and stored according to different uses and varieties. From harvesting to storage, to reduce the number of tipping as far as possible, and pay attention to light handling, light handling, light transportation, so as not to damage the potato skin.