Detailed Explanation of Key Techniques for Saving Seed Potatoes from the Autumn Crop

1. Fine land preparation For autumn potatoes, choose a field with high terrain, convenient drainage and irrigation, and fertile soil, preferably loamy soil.

2. Sprouting seed potatoes In mid-August, remove diseased potatoes, cracked potatoes, and irregular potatoes from the harvested spring potatoes, and cut them into pieces according to the seed potato eyes. Cut each seed potato lengthwise into 4-6 pieces, and prepare a medicinal solution by mixing 0.1 g of gibberellin with 100 kg of water. Soak the potato pieces for 10-20 minutes, take them out and let them dry, then stratify them with wet sand to promote sprouting. During the sprouting period, generally do not sprinkle water, and keep the sprouting temperature above 30°C. Under low-temperature, ventilated, and moist conditions, when the sprouts grow to about 3 cm in 6-8 days, take the potato pieces out of the sand and air them in the shade of a tree for 1 day to harden the seedlings.

3. Sowing at the right time and applying sufficient base fertilizer For seed potatoes saved from the autumn crop, sowing should avoid the high-temperature season to ensure that the potatoes emerge smoothly and that the tuber-setting period avoids the high-temperature season, so as to reduce seed potato degeneration and maintain seed characteristics. Sow in late August when the temperature drops. At sowing, apply 3000 kg of high-quality farmyard manure, 15 kg of urea, and 20 kg of potassium sulfate per 667 sq m into the sowing furrow along with the seed potatoes, then plant the seed potatoes.

4. Reasonable close planting Autumn-sown potatoes should be appropriately denser than spring-sown potatoes. At sowing, open shallow furrows with a row spacing of 50 cm and a plant spacing of 20 cm. Use about 120 kg of seed per 667 sq m, and plant 7000 plants. After planting, cover with soil 10 cm thick to form natural ridge beds.

5. Field management In early September, after the seed potatoes have all emerged, strengthen water and fertilizer management to ensure the potato seedlings have sufficient fertilizer and water. During the seedling stage of autumn-sown potatoes, the temperature is relatively high, so pay attention to drought prevention and drainage. Water in time when drought occurs, keep the field surface moist and the furrows from drying out, so that the potato seedlings start early and grow quickly, form sufficient photosynthetic area, and promote tuber formation. After each watering, cultivate soil as needed. During the potato growing period, generally cultivate soil 2-3 times.

6. Pest and disease control Autumn-sown potatoes are prone to late blight and autumn aphids. If late blight-infected plants are found, pull them out promptly, take them out of the field, and burn them. You can use 65% mancozeb at 100 g per 667 sq m or 40% phosethyl-Al at 150 g, mixed with 30 kg of water for uniform spraying control, spraying once every 7-10 days, for 2-3 consecutive sprays. You can use 40% omethoate at 100 g per 667 sq m or 25% mieyaling at 50 g, mixed with 50 kg of water for uniform spraying to control aphids.

7. Harvest at the right time At the end of October, after the potatoes have emerged and grown for 60 days, when the leaves in the middle and lower parts of the plants begin to turn yellow, they can be dug up and stored.