Want a high yield from autumn potatoes? Nailing the five key stages is crucial

I. The quality seed selection stage: For seed, choose healthy small potato tubers with smooth skin and relatively shallow eyes, weighing 30-50 grams. Store them in a cool, well-ventilated place. Cut the tubers into pieces and let them dry for 3-5 days before planting, to ensure uniform emergence in the autumn crop.

II. The seed soaking and sprouting stage: Take the selected tubers and cut them lengthwise from the top downward into two pieces, rinse the cut surfaces with cool water to wash away the exuded liquid and starch, then place them in 1% lime water (1 part lime powder to 100 parts clean water) and soak for 1 hour, then remove and place in a shady spot to dry and sprout. There are two sprouting methods: 1. Natural sprouting method: Choose a well-ventilated, cool place with a relatively low temperature, cut the potatoes into small pieces (each piece ensuring 1-3 buds), then wash off the juice with cool water, dry them, and sprout them indoors by covering them in layers with moist sandy soil, piling up three or four layers, covering the surface with rice straw to retain moisture, and keeping the temperature at around 20°C. When the sprouts grow to 1-1.5 cm, take them out and place them in a cool outdoor spot to harden the sprouts for 1-3 days before sowing. 2. Gibberellin sprouting method: Soak the seed pieces in 5-8 ppm gibberellin for 0.5-1 hour, then remove them and immediately bury them in a moist sand bed to sprout. The sand bed should be set up in a cool, well-ventilated place, spread with 10 cm of moist sand, with one layer of seed potatoes and one layer of sand, arranged in 3-4 layers. After 10-15 days, when the sprouts grow to about 2 cm, the sprouts can be hardened and sown.

III. The land preparation and sowing stage

1. Drought prevention ① First treat the seed pieces properly, and wait until there is sufficient soil moisture before sowing. ② Open beds 3 m wide in the field, dig the sowing furrows well, with a row spacing of about 40-50 cm. 1-2 days before sowing, channel water into the furrows to soak the beds or manually water to increase soil moisture. Make the sowing furrows and the soil clods on both sides moistened by water seepage. In the sowing area, loosen the soil layer and place the seed pieces at a plant spacing of 20 cm. ③ If sowing on a very sunny day, it is best to do it before 10:00 in the morning or after 5:00 in the afternoon, and use staggered-row drilling between rows to facilitate ventilation and light. Generally do not ridge. ④ The soil and miscellaneous manure used to cover the seed must be finely broken up, mixed evenly and moistened with water beforehand; after applying it, also cover it with a thin layer of fine soil on top. ⑤ After sowing, spread coverings such as rice straw, thatch grass or wheat straw on the bed surface, and remove them after 20%-30% of the seedlings have emerged.

2. Timely sowing: The sowing period should be in early to mid-September, when the daily average temperature is stable below 30°C. Before sowing, control underground pests well; you can use 48% chlorpyrifos or a 1000-fold dilution of Suifeng for spraying. Sow and cover with soil at the same time; after covering with soil, use 50-60 g of 90% pendimethalin per 667 sq m diluted in 100 kg of water for uniform spraying to control weeds. At the same time, cover the bed surface with rice straw or green grass to retain moisture, prevent rain damage, lower soil temperature, and help seedling emergence. 3. Reasonable close planting: Autumn potatoes are generally planted at 5500-6000 hills per 667 sq m, with a seeding rate of 160-180 kg per 667 sq m, wide rows and narrow plants, with a row-to-plant spacing of 40 x 25 cm. When the seedlings are about 15 cm tall, earth up to increase soil permeability, which is conducive to high yield.

IV. The field management stage

1. Apply sufficient base fertilizer: Autumn potatoes have a short growth period, so sufficient base fertilizer must be applied. Apply about 1500 kg of decomposed livestock and poultry manure and 50 kg of 45% potassium sulfate compound fertilizer or 50 kg of special compound fertilizer per 667 sq m, applied in furrows and then covered with soil. At the 6-7 leaf stage, apply topdressing well according to seedling condition, and make sure to irrigate with running water during drought and prevent waterlogging on rainy days. For late blight, spray with a 700-800-fold dilution of 72% Kelu.

2. Topdressing and water management: Earthing up is very important for potato cultivation. It can not only increase the number of stem nodes buried in the soil and induce more stolons to form tubers, but also prevent stolons from being exposed to light and failing to form tubers, or tubers from turning green in the light and stopping growth. Because rice straw mulching is used, no earthing up is needed at the seedling stage; earth up once at the branching stage (around the 12-leaf stage), and earth up heavily once when the rows close. Earthing up can be done in combination with clearing the furrows, or by using ash to hill up the plants. Autumn potatoes need a lot of fertilizer and have a short growth period, so base fertilizer should be the main source, with topdressing 2-3 times according to seedling condition, and timely intertillage and weeding at the same time. At the branching stage, apply a tuber-promoting fertilizer once, splashing 700 kg of manure water per 667 sq m; this topdressing can be completed in combination with earthing up; at the tuber formation stage (around flowering), spray the stems and leaves 1-2 times with 3% monopotassium phosphate plus 3% urea solution; when doing foliar topdressing, adding a mixed solution of 0.1% copper sulfate and boric acid gives an even better yield increase effect. For water management of autumn potatoes, on the one hand prevent waterlogging at the seedling stage that causes tuber rot, and on the other hand prevent water shortage at the tuber formation stage; especially around flowering, the plants are extremely sensitive to water, and water shortage will cause severe yield reduction. When irrigating, just soak the furrows with a small amount of water; it should not overflow the bed surface.

V. The pest and disease control stage: Apply pesticides in time, and control potato late blight and aphids well. The most effective pesticide for controlling late blight is a 600-fold dilution of 25% metalaxyl mancozeb, or a 700-800-fold dilution of 72% Kelu for spraying; the effective pesticide for controlling aphids should be a 2000-3000-fold dilution of pirimicarb for spraying.