Detailed Explanation of Key Techniques for Spring Potato Cultivation

1. Selecting suitable varieties: Choose suitable varieties according to different soil conditions and climatic characteristics. At present, the improved varieties introduced, planted, demonstrated and promoted in our county mainly include: Dongnong 303, Favorita, etc. It is advisable to use virus-free potato foundation seeds or first-generation and second-generation seed potatoes, and it is forbidden to use commercial potatoes as seed potatoes.

2. Seed potato treatment: Seed potatoes should be healthy and disease-free, undamaged, with smooth skin, well stored, and showing the characteristics of the variety, and should be uniform in size. For large seed potatoes, cut them into pieces for propagation usually a few days before sowing. The method is: use a sterilized sharp knife to cut vertically from the top of the seed potato downward into small pieces. Note that the pieces cut from the top should be slightly smaller, and the pieces cut from the rear should be slightly larger. They should be cut into prism-shaped pieces, and must not be cut into thin slices. Each piece should weigh about 20-30 grams and retain 1-2 buds. After cutting the potato pieces, coat the wounds with plant ash to prevent decay from affecting sprouting.

3. Timely planting: In order to ensure high yield and increased income of potatoes, it is suitable to sow in mid-January with plastic film mulching, and potatoes can be harvested in early to mid-May of the following year.

4. Land selection and preparation: Choose fields where the previous crop was not Solanaceae crops or root crops such as carrots, with loose soil, rich in organic matter, medium or higher fertility, deep soil layer, and convenient drainage and irrigation. Deep plow, harrow finely, level evenly, and smooth the surface; then make beds at a width of 2 m including the ditch, with a bed height of 20 cm and a bed surface width of 165 cm. Plant 4 rows per bed, with a row spacing of 50 cm and a plant spacing of 25 cm.

5. Applying heavy base fertilizer: Generally, apply 1500-2000 kg of farmyard manure, 20-50 kg of phosphate fertilizer (calcium superphosphate), and 30 kg of compound fertilizer per mu. Mix them thoroughly, open planting furrows 10 cm deep on the prepared bed surface, spread the fertilizer evenly into the planting furrows, and then cover with a small amount of soil.

6. Reasonable close planting: Determine a reasonable planting density according to soil fertility conditions and variety characteristics. Under general fertility conditions, planting 5500 plants per mu is appropriate, and the seed requirement per mu is 130-150 kg. Place seed potatoes in the planting furrows with base fertilizer at a plant spacing of 25 cm, planting a single plant per spot, with the buds facing upward, then cover with 8-10 cm of fine soil, and then cover with ultra-thin plastic film.

7. Intensive field management:

1. Breaking holes and guiding seedlings out, covering soil to preserve heat: 3-5 days after emergence, manually break the film to release the seedlings, then seal the holes with fine soil to preserve heat and prevent sunlight from burning the seedlings. After the seedlings emerge, pay attention to weather changes and do a good job in protecting the seedlings against late frost and freezing damage.

2. Pest and disease control: When sowing, apply phoxim by watering into the planting furrows to prevent underground pests; if bacterial wilt or late blight occurs, spray 1-2 times with 50% carbendazim wettable powder or 50% thiophanate-methyl wettable powder at 800 times dilution.

3. Foliar fertilization: In the late growth stage, use 100 grams of potassium dihydrogen phosphate plus 250 grams of urea per mu, dilute with 50 kg of water, and carry out 1-2 foliar sprays to prevent premature senescence of the plants and promote more tuber formation and larger tubers.

4. Timely harvest: When potato growth stops, the stems and leaves gradually turn yellow and withered, and the stolons and tubers easily separate, harvest should be carried out in time. If harvested too early, the tubers are immature, dry matter accumulation is low, and yield is low; if harvested too late, it is easy to cause tuber rot, reduce quality, and affect yield. Choose sunny days to dig potatoes, store them by size category, and after the surface moisture of the tubers is dried, put them into mesh bags for transportation and sale.