Detailed Explanation of Key Points of Winter Potato Cultivation Techniques

I. Sow at the right time to seek advantages and avoid disadvantages. The best sowing time for winter potatoes is when the soil temperature at a depth of 10 cm reaches 7 or 8°C. Within the range not affected by frost, sow as early as possible. This allows harvesting before the arrival of high summer temperatures and helps obtain a higher yield. Late sowing leads to severe late blight in the later stage and poor storability.

II. Select good varieties and promote sprouting to encourage seedlings. Potatoes are planted in different locations to help resist disease and achieve high yield. Choose varieties such as Zihuabai Kexin No. 3 and Kexin No. 1, which have high yields. Before sowing, sprouting must be carried out. There are two methods: first, indoor moisture-retention sprouting, that is, 7-10 days before planting, place the seed potato pieces in a vat and seal it to keep warm and promote sprouting; second, field sprouting, cut the potato pieces into small pieces, dip them in plant ash, place them flat on the ground and cover with sand, and plant after buds appear.

III. Rational close planting and sufficient seed quantity. Planting density should be determined according to variety, soil fertility, season, and so on. Use double-hole planting, with row spacing of 40 cm and plant spacing of about 35 cm, planting 3000-5000 plants per mu. In order to save seed quantity, cut large potato pieces into small pieces. Generally, 1 jin of seed potatoes is best cut into 10-20 pieces. When cutting, note that the cut should be made longitudinally from the top to the navel, so that each piece has a bud eye at the top, ensuring emergence. The seed quantity per mu is generally 75-100 kg.

IV. Fine and coarse land preparation and scientific management. Potatoes like warmth and moisture but fear waterlogging, so it is best to choose loose sandy loam with convenient drainage and irrigation and medium fertility for cultivation. After the late rice is harvested, use 750-1000 kg of organic fertilizer such as pig, chicken, duck, and mixed manure, 25 kg of superphosphate, and 10 kg of potassium fertilizer as the core fertilizer in the bed. Then, prepare the land into seedbeds with a bed surface width of 110-120 cm and a ditch width of about 50 cm for sowing. Because winter potatoes have a short growth period, only scientific management can achieve high yield. In fertilization, apply heavy base fertilizer, topdress early, apply sufficient organic fertilizer, and increase phosphorus and potassium fertilizer, with N:P:K = 1:0.5:2. Topdressing is generally applied in two times. The first time is 3 days after emergence, using 500 kg of coarse manure water plus 2 kg of urea per mu, poured into the holes to promote stolon formation. The second time is 3-5 days before budding, using 500-600 kg of decomposed human manure and urine plus 2.5 kg each of urea and potassium fertilizer per mu, poured into the holes. During the entire growth period of potatoes, water management should mainly keep the soil moist. In drought, irrigate with running horse water; in the rainy season, drain frequently.

V. Intertillage and hilling, thinning and final seedling setting. Intertillage and hilling are generally carried out together with topdressing. The first intertillage and hilling should include replanting. Keep two plants per hole. The second intertillage should be combined with cleaning ditches and hilling.

VI. Timely prevention and control of pests and diseases to strive for a bumper harvest. The main pests and diseases of potatoes include bacterial wilt, late blight, cutworms, aphids, and so on. Cutworms can be poisoned with isofenphos-methyl bait, and aphids can be controlled with imidacloprid. To prevent and control bacterial wilt and late blight, on the premise of selecting disease-resistant varieties, use scientific water management and timely removal of diseased plants, and so on. For bacterial wilt, use 50% thiophanate-methyl at 800 times or agricultural streptomycin at 50-100 ppm for control. For late blight, use 25% metalaxyl wettable powder, 2 liang plus 60 kg of water, for spraying.