Detailed Explanation of Key Points for Winter Potato Cultivation Techniques

Variety selection: Choose virus-free potato varieties with high yield, wide adaptability and good market quality, such as Zihua 851 and Kexin No. 3.

Seed potato preparation: Generally, small seed potatoes of 25-30 grams are selected for sowing. Sprout the seed potatoes 20 days before sowing. Soak intact seed potatoes in a 10 mg/kg gibberellin solution for 15 minutes, then place them in moist sand to sprout. Be careful to keep the sand moist and prevent waterlogging. For cut seed potatoes, each piece should have more than 1 vigorous sprout. After cutting, dip the cut surfaces in plant ash for sprouting. When the sprout reaches 1 cm and white root points appear at the base of the sprout, this is the standard for completed sprouting. If the sprouts are too long, they will break after being covered with straw; if the sprouts are too short, growth will be slow.

Land preparation: After the late rice is harvested, deep plow and finely harrow the paddy field, plow good high-yield furrows, break up and finely level the soil clods on the bed surface evenly, and make the bed surface slightly arched to prevent waterlogging. The ditch width is 30 cm, the ditch depth is 18 cm, the surrounding ditch depth is 30 cm, and the bed width is 80 cm.

Sowing: Sowing is carried out from "Minor Snow" to "Major Snow" solar terms, with double-row bed planting, plant spacing of 30 cm, and 3500-4000 plants per mu. When sowing, place the seed potatoes directly on the bed surface with the eyes facing upward and press slightly so that the seed potatoes make full contact with the soil, which helps rooting and emergence.

Straw covering: Immediately after the seed potatoes are placed, cover them neatly and evenly with rice straw. Use rice straw that has been cut for more than 5 days, cover it perpendicular to the bed surface, with a thickness of 8 cm, using about 1000 kg of rice straw per mu. After the straw covering is completed, press soil from cleaning the ditches on top of the straw to prevent light leakage and the straw from being scattered by strong wind. Do not cover with plastic film after straw mulching. If a cold wave occurs, plastic film should be added for cold protection, and the film should be removed promptly after the cold wave passes.

Water and fertilizer management: Before sowing, apply 1200 kg of decomposed human manure per mu, 50 kg of compound fertilizer, and 30 kg of calcium magnesium phosphate evenly between 2 plants. Be careful to keep a distance of 5-8 cm between the seed potatoes and the fertilizer to prevent potato rot and missing plants. After budding, spray TA milk powder once every 10 days, 3 times in total, for foliar topdressing.

After sowing, irrigate moderately through drainage and irrigation ditches to keep the soil moist, ensure uniform and strong seedlings, and drain promptly. Generally, natural rainfall in normal years can meet the growth needs of potatoes. In the middle and late growth stages of potatoes, if there is rainy weather, especially continuous spring rain, clear the ditches and drain promptly to reduce field humidity and prevent the occurrence of diseases such as late blight due to high humidity of the straw near the soil surface, which dries slowly.

Pest, disease and weed control: In potato cultivation with rice straw mulching, field humidity is relatively high. In the middle and late growth stages, under climatic conditions with relatively high rainfall, special attention should be paid to the control of late blight. After the budding stage, conduct field surveys frequently, and once disease is found, spray pesticides promptly for control. The main insect pests include aphids and the 28-spotted ladybird beetle, which can be controlled with general insecticides. Rice straw mulching cultivation can effectively inhibit weed growth, so no weeding is needed.