Key Techniques for Three-Membrane Covered Cultivation of Winter-Spring Potatoes

Three-membrane covered cultivation techniques for winter-spring potatoes (large arch shed, small arch shed, plastic film). Generally, sprouting is promoted and sowing is done in December, and harvest takes place at the end of March the following year. Each mu can yield about 3500-4000 kg of potatoes. It reaches the market one month earlier than early-spring plastic film covered potatoes, and the economic benefits are very significant. The cultivation techniques are as follows:

1. @#@185@#@ Shed construction specifications and planting specifications

(1) Site selection and shed construction specifications. Choose plots with loose soil, sufficient water sources, and convenient drainage and irrigation to build sheds. Large arch sheds are generally 60 m long, 6 m wide, and 2-2.50 m high. Inside the large arch shed, build two small arch sheds 0.80-1.20 m high and 2.40 m wide. The small arch sheds are 35 cm away from the large arch shed, and the two small arch sheds are 50 cm apart. This serves as a walkway and also facilitates management.

(2) Planting specifications. Within each small arch shed, use 2.40 m as one planting belt. After land preparation and bed making, four ridges can be formed for cultivation.

2. Land preparation and fertilization

Greenhouse land is generally deep-plowed 20-25 cm, leveled and raked fine. In combination with land preparation, apply 2000 kg of decomposed organic fertilizer, 20 kg of diammonium phosphate, and 200-250 kg of plant ash per mu.

3. Variety selection

For winter-spring three-membrane covered potatoes, it is advisable to choose early-maturing varieties with a short dormancy period, early tuber formation, and resistance to rot, such as Luyin No. 1, Kexin No. 13, etc.

4. Seed potato treatment

For sowing, it is best to choose small whole seed potatoes of about 50 kg, as they are less likely to rot after sowing and grow vigorously. Large seed potatoes can also be cut into pieces for sowing. Generally, 15-20 days before sowing, soak the seed potatoes in a 0.01% gibberellin solution for 3-5 minutes, then remove and air-dry them, place them in a hotbed at 15-18°C to promote sprouting, maintain 60%-70% relative air humidity, and after 20 days, when sprouts are 1-1.50 cm long, they can be planted.

5. Timely sowing

(1) Winter-spring potato three-membrane cultivation can be sown in late December, after seed potato sprouting is completed, choosing sunny, warm, and windless weather.

(2) Sowing density. Since winter-spring potatoes with three-membrane coverage are mostly cultivated for early maturity, generally about 5000 plants can be cultivated per mu, with row spacing and plant spacing of 60 cm x 18-20 cm.

(3) Sowing method. When sowing, open furrows at a row spacing of 60 cm in each finely leveled and raked bed, with a furrow depth of about 3 cm. After opening the furrows, water them, then sow at a plant spacing of 18-20 cm. After sowing, form ridges and cover with 8 cm of soil, then cover with plastic film, and then cover with small arch sheds. This forms three-membrane coverage.

6. Field management

(1) Temperature and humidity management. Since sowing occurs during the cold season, the temperature inside the small sheds should be maintained at 18-20°C during the day and 10-15°C at night to facilitate seedling emergence. If cold waves or heavy wind and snow occur during the growing season, straw mats can be placed over the small arch sheds to maintain shed temperature. During the growing period, keep the soil moist. After the branching stage, maintain sufficient moisture to facilitate stem and leaf growth. If drought occurs, timely irrigation can be carried out by furrow irrigation.

(2) Fertilizer and water management. If fertilizer is lacking during the growing period, fertilization can be carried out in combination with watering, generally applying 5 kg of urea per mu.

(3) Because plastic film is used for coverage, when seedlings push through the soil, the plastic film should be cut open in time to facilitate seedling emergence. When potatoes show buds, remove the flower buds in time and irrigate heavily to facilitate tuber expansion.

7. Pest and disease control

(1) Early blight can be controlled with 1:1:200 Bordeaux mixture or with 64% Mancozeb (Shadufan) wettable powder at 500 times dilution. Late blight can be controlled with 72% Kelu wettable powder at 700-800 times dilution.

(2) Aphids, etc. can be controlled with 50% omethoate at 600 times dilution.

8. Timely harvest

Generally, in late March, when the plant leaves have basically turned yellow and the tubers have fully expanded, harvest can be carried out in time according to market conditions.