Detailed Explanation of Key Cultivation Techniques for Winter Potatoes

Potatoes are a crop that provides both food and income while enriching the soil. Using idle winter fields to grow potatoes is an effective way to build soil fertility and increase farmers' income. The key cultivation techniques are as follows:

1. Site selection and land preparation: For winter potatoes, choose sandy loam or tidal sandy mud fields with convenient transportation, fertile soil, deep soil layers, loose structure, and good drainage and irrigation conditions. When harvesting the late-season rice, cut the rice stubble low, plow deep and harrow fine, and form ridges and beds 1.2 m including the furrow, with a bed width of 0.85-0.9 m, a furrow width of 0.25 m, and a ridge height of 0.25 m. Land preparation requires fine, crumbly soil clods and straight, level ridge surfaces and furrow bottoms.

2. Seed potato treatment: (1) Seed potato storage. Remove diseased and rotten tubers from the seed potatoes, choose a cool, dry place for sand storage, use dry fine sand as a 5 cm base layer, place a layer of seed potatoes, then cover with another layer of fine sand. (2) Seed potato cutting. 1-2 days before sowing, cut into 25-50 g seed pieces with 1-2 buds. If a diseased tuber is cut, soak the knife in a 0.5% potassium permanganate solution for several seconds before continuing. When cutting, first make a diagonal or ring cut from the base, then cut the apical bud lengthwise into two pieces, keeping as much tuber flesh as possible. (3) Seed potato disinfection. Mix 2.5 kg gypsum powder, 12.5 g thiophanate-methyl, and 12.5 g metalaxyl-mancozeb, then dust it on the cut surfaces of the seed potatoes to prevent disease and rot, and store the apical tuber pieces and basal tuber pieces separately in a cool, dry place with scattered light.

3. Timely sowing: Sowing in early to mid-November is appropriate. Generally, sow 4000-5000 plants per mu. Before sowing, first open a deep furrow in the middle of the bed and apply base fertilizer: 1500 kg organic fertilizer, 15 kg phosphate fertilizer, and 10 kg urea per mu, mix evenly, and cover with soil. Plant two rows per bed, with a plant spacing and row spacing of (0.25-0.3) m x 0.25 m, in a triangular pattern of hole sowing, keeping them as close to the middle of the bed as possible to facilitate hilling after planting.

4. Scientific fertilization: Apply sufficient base fertilizer, apply topdressing early, skillfully apply foliar fertilizer, and apply frequently and lightly. When about 60% of seedlings have emerged, apply a full-stand fertilizer, using 3 kg urea per mu diluted with 1750 kg human excrement and urine or water for drenching; after 10 days, apply a tuber-setting fertilizer, using 7.5 kg urea per mu diluted with 1750 kg human excrement and urine or water for drenching; before flowering and ridge closure, heavily apply a tuber-bulking fertilizer, using 10 kg compound fertilizer plus 5 kg potassium sulfate per mu diluted with 1750 kg water for drenching, and combine it with spraying potassium dihydrogen phosphate solution as a foliar fertilizer; 0 days before harvest, spray 1 g "920" per mu diluted with 75 kg water to delay senescence and increase yield.

5. Water management: Potatoes are sensitive to water, and their water requirements are characterized by: little in the early stage, much during tuber setting and bulking, and little later. Therefore, after sowing, if drought causes the topsoil to turn white, promptly irrigate with running water to keep the soil moist, preventing alternating dry and wet conditions that cause deformed tubers. Drain all standing water 15 days before harvest to avoid tubers absorbing too much water and cracking or rotting.

6. Timely hilling: To prevent weeds from competing with potatoes for nutrients, increase the tuber-setting layer and raise yield, prevent tubers from turning green and becoming deformed, and improve the marketable rate, hilling is required at least twice. The first is carried out within 10 days after full emergence when the seedlings are about 20-25 cm tall, with furrows cleaned and heavy hilling done; the second is carried out before the stems and leaves close the rows. In the middle and late stages, frequently check the bed surface near the plants, and if there are cracks, hill up promptly. When hilling, avoid damaging the stems or pressing down the leaves.

7. Disease and pest control: The main diseases and pests of potatoes include cutworms, mole crickets, aphids, potato tuber moths, bacterial wilt, late blight, and ring rot. After full emergence, use pymetrozine plus acaricide to control aphids and mites; at the first fertilization, add 0.5 kg phoxim and 0.25 kg Yeqingshuang per mu to control underground pests, bacterial wilt, and ring rot; at the third fertilization, add 0.5 kg trichlorfon per mu to control potato tuber moths; in the later stage, control late blight by spraying 800-fold metalaxyl-mancozeb solution after row closure, once every 10 days.

8. Timely harvest: When potato stems and leaves turn yellow and the basal leaves fall off, they can be harvested. Choose a sunny day, use a plow without a moldboard to turn the ridges and pick up the tubers to reduce damage, and discard green-headed or green tubers, and directly @#@136@#@ or spread them indoors to dry, avoiding direct sunlight, which affects quality.