When is the best time to harvest sweet potatoes? Master the four key points of timely harvesting
Many farmers believe that growing sweet potatoes does not require fertilization, but this is actually a misconception. Only by mastering the correct fertilization methods can sweet potatoes be grown with high quality and high yield. Look at the seedling condition: during the branching and tuber-setting stage, the underground root network forms, the tubers begin to swell, and the ability to absorb fertilizer is strong. At this time, the sweet potato leaf area increases and photosynthetic efficiency rises...
The suitable harvest time for sweet potatoes should be determined based on climatic conditions, safe storage time, and the arrangement of the following crop. However, harvesting too early will significantly reduce the yield of sweet potatoes; harvesting too late means sweet potatoes are often affected by low-temperature chilling injury, store poorly, and have a reduced drying rate. Therefore, when harvesting, attention should be paid to the four key points of "ground," "soil," "seed," and "use.""Ground" means harvesting according to ground temperature. When the ground temperature is around 18°C, the weight of sweet potatoes increases very little; when the ground temperature is around 15°C, sweet potatoes stop swelling; when the ground temperature stays below 9°C for a long time, chilling injury will occur. Therefore, harvesting and digging of sweet potatoes generally begins when the ground temperature is 18°C, and is completed before the killing frost. Spring sweet potatoes used for drying or those followed by winter wheat are generally harvested and dug before Cold Dew; summer sweet potatoes kept for seed are harvested and dug before Frost's Descent; sweet potatoes stored for eating are harvested and dug a little later, but must be completely harvested before the killing frost.
"Soil" means harvesting according to soil moisture. Soil that is too dry or too wet is unfavorable for sweet potato harvest. If too dry, soil moisture content decreases, ground temperature varies greatly, sweet potatoes are prone to chilling injury, and digging is not easy. If too wet, soil moisture content is excessive, and sweet potatoes are not only difficult to dig but also have high moisture content and store poorly after harvest. When the soil is too wet, the sweet potato vines should first be cut off and left to dry for a few days, and digging should wait until the soil is slightly dry.
"Seed" means harvesting according to whether the crop is kept for seed. Summer sweet potatoes kept for seed should be harvested and dug on a sunny morning, dried in the field for a while, and placed into storage that same afternoon. Do not leave them in the field overnight to avoid chilling injury.
"Use" means storing according to purpose. After sweet potatoes are harvested and dug, the tubers can be selected in the field, removing diseased, damaged, and water-soaked tubers, and storing them separately according to different uses and varieties. From harvesting and digging to storage, the number of times they are turned over should be minimized, and care should be taken to handle, place, load, and transport them gently to avoid bruising the tuber skin.