When to start sweet potato slips? How long the nursery period lasts and how to plant

In the past, when farmers raised sweet potato slips, they usually stored the sweet potatoes directly until spring, when they sprouted and grew vines, and then cut the vines into sections and planted them in the soil to grow. In fact, there are now many methods for raising sweet potato slips, and as long as you master the techniques, a high yield is not impossible. So when do sweet potatoes generally start to be raised for slips? How long is the nursery period? How do you plant them?

Sweet potato slip-raising time:

Seed sweet potatoes should all be raised by mid-February to mid-April. Spring sweet potato breeding is mostly done around Awakening of Insects; in areas south of the Huai River, breeding begins after mid-February, while in areas north of the Huai River it is finished before April 10, mainly using hotbeds or cold frames covered with plastic film. Open-field potato arrangement is mostly done before April 20; when open-field breeding is used without plastic film covering, it is more suitable to raise the slips more than 45 days before planting the seedlings.

Slip-raising methods:

1. Sweet potato vine winter dormancy slip-raising method

The sweet potato vine winter dormancy slip-raising method keeps sweet potato vines harvested in autumn until the second year to use as sweet potato slips.

1. Cutting the vines: After the autumn sweet potato harvest, select robust sweet potato vines free of frost damage and disease, remove the leaves, keep 1 cm of petiole, and cut them into sections of two nodes each.

2. Forced dormancy: Soak the cut sweet potato vines in a 0.5% Amphetalin solution for two minutes, then take them out and dry the surface moisture.

3. Sieving the sand: Filter ordinary yellow sand through a sieve to remove large sand grains and impurities, then sprinkle with water; the moisture level should be such that the sand can be squeezed tightly and then scattered apart when released.

4. Sand storage: First dig a pit in the ground; length and width are unrestricted, and the depth is 1.2 m (depending on the thickness of the winter frozen soil layer in each area, with a storage temperature of 5-10°C being suitable). Then place the sweet potato vines flat in the pit using a layer of vines and a layer of sand, leaving a 1 cm gap between vines. Each layer of sand should be no less than 3 cm thick, and the top layer of sand should be no less than 15 cm thick. Cover the surface with plastic film; in areas with heavy frost, cover the film with straw or grass curtains as well. By the spring sweet potato planting season the following year, take out the sweet potato vines and plant them as cuttings. The sweet potato vine winter dormancy slip-raising method can save the land occupied by seed potato slip-raising and the field management during the nursery period. After sand storage, the sweet potato vines taken out already have a small amount of new roots, and after cutting they survive quickly and grow well, which can increase sweet potato yield per unit area by 15-20%.

2. Sweet potato root slip-raising method

The sweet potato root slip-raising method transplants sweet potato roots harvested in autumn into a greenhouse or onto a building balcony, and cultivates sweet potato vines throughout the winter to keep as sweet potato slips.

1. After the autumn sweet potato harvest, select robust sweet potato vine roots free of frost damage and disease. On the upper part of the vine roots, leave 2-3 nodes upward from the root on each vine, remove the leaves, and keep 1 cm of petiole for later use.

2. According to how many sweet potato slips are to be raised, choose a suitable nursery site. In a greenhouse, dig small trenches (30 cm wide, 20 cm deep) with a trench-center spacing of 80 cm, and plant the sweet potato roots on both sides of the small trenches at a plant spacing of 20 cm, generally planting 12 plants per sq m. On a house balcony, sweet potato roots can be planted in flower pots, using the same method as greenhouse cultivation.

3. Above the ground in the greenhouse or on the house balcony (about 1.6 m above the ground), stretch No. 14-16 wire according to the row and plant spacing of the planted sweet potato roots, and tie some plastic rope or hemp rope to the wire. Tie one end of the rope to the wire and the other end to the sweet potato root. After the vines on the sweet potato roots sprout, keep 3 robust sprouts per plant, with one sprout corresponding to one rope, so that after the sweet potato roots sprout, the vines climb upward along the ropes.

4. The newly grown sweet potato vines need to be manually wound around the ropes, generally once every 1-2 days. When the sweet potato vines have grown to 1.5-2 m long and there are still about 10 days before transplanting to the field, the sweet potato vines can be harvested. Remove the leaves, keep 1 cm-long petioles, cut into sections of two nodes each, tie every 200-300 sections into a bundle, plant them in greenhouse soil or flower pots, and water thoroughly, with a depth of about 5 cm being suitable. After about 10 days, small buds sprout from the upper part of the sweet potato vine sections and a certain root system sprouts from the lower part; at this point they can be transplanted to the field.

The sweet potato root slip-raising method has the characteristics of fully using space and producing a large number of slips, and the sweet potato roots can also yield a certain amount of sweet potatoes in spring. When using this method to raise slips, the temperature in the greenhouse or on the house balcony should be controlled between 5-25°C, and should not be too high or too low. Generally, 400-600 sweet potato slips can be raised per sq m.

3. Sweet potato vine slip-raising method

The sweet potato vine slip-raising method is to select robust sweet potato vines free of frost damage and disease after the autumn sweet potato harvest, remove the leaves, keep 1 cm of petiole, and cut them into sections of two nodes each to form sweet potato vine sections. The subsequent operations are the same as the sweet potato root slip-raising method.