1, time selection: the big difference between the north and the south, set a good point in time Southern nursery time: February - April, before and after the hibernation of the lunar season, do not need to use the greenhouse nursery, you can cover the film. Northern nursery time: mid-April, must be greenhouse or hotbed nursery, strict temperature control, to maintain at 15 ℃ above 30 ℃ below. It should be reminded that the nursery time should be based on when to plant seedlings in their own plots, sweet potato seedlings should be 45-50 days before they can be transplanted, plan the time, don't let the seedlings too big or too small.

2, sweet potato tuber seedling method is a common method of sweet potato planting, spring potatoes usually use this method, seedling time can be very good control, and this method of seedling production, potato fast easy to store, the disadvantage is that the seed potato disinfection is difficult to get rid of, easy to carry a variety of overwintering diseases, sweet potato seedlings disease rate is high, in the seedling period and the growth period should pay attention to the occurrence of various diseases. Seedling time is set in the early spring of February-April, in mid-April before the seedling finished.

3, potato seedling nursery method: this method is to intercept the spring potato seedling, each seedling 20-30cm long, direct rootless planting. This kind of seedling is suitable for fall potato planting, in the south of China and Shandong, Henan is suitable for planting. The advantage of this kind of seedling is that it effectively eliminates the carrying of diseases, which is equal to the automatic disinfection of the seedling period; the disadvantage is that the truncated sweet potato seedling needs to re-grow its roots, and the seedling repair time is longer, and it is necessary to choose the right time when planting, and the production time is too short, which will result in a reduction in yield.

4, potato root seedling method is in the sweet potato harvest, the long roots of sweet potato as seedling seed root, without big potatoes, put the root into the greenhouse or home indoor planting, so that the sweet potato root grows out of the seedling in the winter growth, such as the following year as spring potato seedling planting. The temperature of the greenhouse or house should be controlled between 5-25℃, not too high or too low, and generally 400-600 sweet potato seedlings can be cultivated per square meter. Seedling time: after frost or before winter, November-December.

5, sweet potato vine seedling method is to use before the frost of the sweet potato vine, continue to follow the autumn potato planting method, the vine will be truncated into 20-30cm seedling section, planted in the greenhouse or indoor planting, so that the seedling grows for a winter, and so on the next year for the truncation of the planting. The spring potatoes planted in this way belong to the rootless sterilized planting, which is better than tuber planting, but it is troublesome when it comes to nursery, and requires specialized care and temperature control.