Key Techniques for Plastic Film Mulch Cultivation of Spring Potatoes

Spring potatoes are sown from late January to early February and harvested and marketed in mid-May, yielding about 1700 kg of tubers per mu, with relatively high economic returns. The cultivation techniques are as follows:

1. Select good varieties and strictly treat seed potatoes. Choosing excellent virus-free potato varieties is the foundation of high-yield cultivation. Suitable varieties should be early-maturing, high-yielding, stable-yielding, with strong comprehensive disease resistance and good quality. Cut the seed potatoes lengthwise into pieces of 50-80 g each, ensuring each piece has upper buds, and dip them in a 1:200 solution of carbendazim or coat the cut surfaces with plant ash, then spread them out to dry for 1-2 days until the seed pieces begin to soften.

2. Apply sufficient fertilizer, deep plow and form ridges. Potatoes have a short growth period, and with plastic film cultivation, a one-time application of sufficient basal fertilizer is adopted. Apply 3000 kg of high-quality ash manure per mu, then deep plow, break up the clods and form ridges. The ridge base width is 85-90 cm, the ridge surface width is 60 cm, and the ridge height is 10-15 cm. Then open sowing furrows along the ridge surface, apply 30-40 kg of high-concentration compound fertilizer per mu along the sowing furrows, and lightly rake the soil surface after application to avoid contact between seed and fertilizer.

3. Reasonable close planting. Timely sowing and reasonable density are the keys to obtaining high yields. Sprout and sow from late January to early February. Use double-row ridge cultivation, with a row spacing of 40-50 cm and a plant spacing of 25-30 cm, 5000-5500 plants per mu.

4. Do well in chemical weeding and plastic film mulching. Before mulching, spray 100 ml of 72% Dual per mu mixed with 50-60 kg of water on the ridge surface. The ridge surface should be flat, the film should be sealed tightly, and the film should be laid firmly. After mulching, promptly clean the furrows and manage soil moisture.

5. Strengthen field management. Promptly break the film to lift seedlings, and use reserved seedlings to fill in dead or missing plants. After full emergence, apply a balanced fertilizer as a top dressing, using 5 kg of urea per mu diluted in water and applied as a spot irrigation. During the tuber formation stage, apply 5 kg of urea per mu as a top dressing, plus 10 kg of high-concentration compound fertilizer as a swelling fertilizer. Spring potatoes generally do not need pruning of branches, but before flowering the flower stems must be removed to concentrate nutrients for tuber expansion. Keep the field moisture appropriate at all times, especially after tuber formation; the field must not accumulate water, and drainage to reduce waterlogging should be timely, otherwise tubers are prone to rot. The main diseases include viral disease, bacterial wilt, and blackleg. Soaking seeds with 1:200 carbendazim can prevent viral disease and bacterial wilt, and drenching the roots with 200-250 PPM agricultural streptomycin can control blackleg. For fields where plants tend to grow excessively at the bud stage, spray 30 g of 15% paclobutrazol per mu diluted in 50 kg of water. At the full flowering stage, spray 25 ml of Vitavax No. 4 per mu diluted in 20 kg of water, which can dwarf the plants and promote the expansion of underground tubers, thereby increasing yield. According to field experiments, after spraying Vitavax No. 4, plant height can be reduced by 7.2 cm, the proportion of large tubers increased by 12.06%, and yield increased by 9.02%.