All my sweet potatoes are round, and the others are long. What is the reason? Please help me answer it. please ...

There are many reasons for this situation of sweet potato. On the one hand, if it is the same variety as others, it is related to topography, soil quality, planting methods and weather. For example, when planting, mechanical plastic film mulching after ridging will make the ridged soil dense. Nowadays, the weather is dry when planting most sweet potatoes in North China, and the rainfall in the later period is too large. It is also related to foliar fertilizer or seedling control preparation used in sweet potato expansion period.