Mid-June. The optimum temperature for the growth and development of potato tuber is 17- 19℃. When the temperature is higher than 25℃, the tuber will grow slowly, and when the temperature is higher than 29℃, the tuber will stop growing. Therefore, after entering the middle of June, when the local ten-day average gas is higher than 25℃, the harvest should be arranged. The leaves of mature potato plants began to turn yellow from bottom to top, and the main stem began to hollow when pinched by hand.

When harvesting, you can use a special potato harvester, or you can use methods such as pulling plough, shovel digging and manuscript planing. When harvesting, if machinery is used, the seedlings must be pulled out first and then harvested, otherwise the potato pieces will be easily damaged or even mechanically damaged. It is best to dry the harvested potatoes in the field for 2-4 hours. After the potato skin is dried, gently wipe off the soil stuck to the skin and box or pack it, and then it is best to go on sale as soon as possible.

Remember not to leave the harvested potatoes in sunlight or scattered light for a long time, which will cause the potato skin to turn green and affect the quality. If it needs to be stored after harvest, the damaged pieces of potatoes should be removed and stored in a ventilated and dark place, which can generally be stored for one and a half months at room temperature. If stored in 4℃ cold storage, it can be stored for more than half a year.

Reference: Baidu Encyclopedia of Winter Potato