Detailed Explanation of High-Efficiency Cultivation Techniques for Spring Potatoes

Spring potato tubers can begin to grow when the soil temperature at a depth of 10 cm reaches 7-8°C, grow vigorously at 10-12°C, and quickly break through the soil. This is the temperature indicator for sowing in various regions.

Potatoes have wide adaptability. Generally, choose fields with loose texture and easy irrigation and drainage, and plow deeply 20-25 cm; make high beds with a bed width of 95 cm, a ditch width of 25 cm, and a depth of 25 cm. Before sowing, apply sufficient base fertilizer all at once, and apply the fertilizer in the center of the bed while preparing the land. Apply 1500-2000 kg of decomposed organic fertilizer, 15 kg of ternary compound fertilizer, and 15 kg of potassium sulfate per mu.

For spring potatoes, choose virus-free varieties that are extremely early-maturing or early-maturing and free of disease and injury, such as Zhongshu No. 2, Zaodabai (vegetable type), Favorita, Zhengshu No. 5 (export type), Huangmazi (high-starch type), Zihuabai, Atlantic (processing type), etc. These varieties are harvested 60-80 days after full seedling emergence, with a yield of 1500-2000 kg per mu. The size of seed potatoes is preferably 50-100 g. If the seed potatoes have not yet broken dormancy 10-15 days before sowing, dormancy must be broken. There are two methods: first, cut the seed potato lengthwise from the top into several pieces, each with 1-2 buds, and make the cuts close to the buds. Second, soak the seed potatoes in a gibberellin solution. Seed soaking is divided into whole-tuber soaking and cut-piece soaking. For whole-tuber soaking, use a 10-20 mg/L gibberellin solution for 30 minutes; for cut-piece soaking, use a 5-10 mg/L gibberellin solution for 5-10 minutes. Preparation of the gibberellin solution: first dissolve gibberellin with a small amount of alcohol or white liquor, then add water. Dissolve 1 g of gibberellin in 100 kg of water to make a 10 mg/L gibberellin solution. Before soaking seeds in the gibberellin solution, wash the starch from the cut surfaces with clean water. After soaking, remove the potato pieces and place them in a cool place to air-dry for 4-8 hours. Never expose them to the sun, to avoid seed rot. The gibberellin solution can be reused for soaking seeds 4-5 times, but do not use too high a concentration, to avoid excessive vegetative growth at the seedling stage. For sprouting, a cold frame, greenhouse, or plastic tunnel can all be used. Spread clean wet sand on the ground (preferably when it forms a ball in the hand and crumbles when the hand is opened), about 10 cm thick, with a bed width of 1 m. After the seed potato pieces are cut, washed, and air-dried, spread them evenly on the seedbed (do not overlap them), with the buds facing up, then cover the potato pieces with sandy soil. Place 2-3 layers in this way, and finally pat the bed surface firm. During sprouting, plastic film can be used to keep warm, maintaining the temperature at 25-28°C, and keeping the sandy soil moist, with the surface sand preferably not turning white. When the sprouts are 1-2 cm long, they can be transplanted.

Generally, wide-narrow row planting is used, with a large row spacing of 80 cm, a small row spacing of 35-45 cm, a hill spacing of 18-20 cm, and a sowing depth of 7-9 cm, planting 5000-6000 plants per mu. The soil must remain moist when transplanting. Single-film or plastic film plus small-arch film "double-film" mulching cultivation can be used, which can increase the proportion of large and medium tubers by 10%-30%, has a significant yield-increasing effect, and can bring the crop to market 10-20 days earlier.

Generally, do not water before seedling emergence. After rain, if the soil becomes compacted, loosen the soil in time to improve aeration. After full seedling emergence, apply a fertilizer to promote plant growth, using 5 kg of urea per mu diluted in water or applying decomposed human manure. At the branching stage, combine with intertillage and shallow hilling; at the tuber bulking stage, combine with clearing the ditches and do intertillage and heavy hilling. In particular, for the Favorita variety, attention must be paid to covering with rice straw to prevent greening of the tubers. At the same time, prevent water accumulation in the field, otherwise the tubers are prone to rot.

If too much nitrogen fertilizer is applied to spring potatoes, excessive vegetative growth is likely to occur. At the bud stage, use 15 g of 15% paclobutrazol wettable powder and dilute it in 45 kg of water for spraying, to control excessive aboveground growth and help produce more tubers. At the full flowering stage, spray 50 kg of 0.2%-0.3% potassium dihydrogen phosphate solution per mu to promote tuber bulking.

The main disease of potatoes is late blight, which occurs severely when there is excessive rain or around the flowering stage. Spray early with 25% ridomil or metalaxyl 800-fold solution. The main pests include aphids, white grubs, and others. In the early stage of aphid occurrence, spraying with 2.5% deltamethrin diluted 2500-fold with water has a good effect. To control white grubs, dissolve 0.5 kg of 90% crystalline trichlorfon in water, then spray it onto 35 kg of fine soil, mix well to make poisonous soil, and spread it in the furrows. Around early May, spring potatoes can be harvested at the late tuber bulking stage.