It's the right time for winter potato planting, seize the good sowing window
In recent years, the cultivated area of potatoes has expanded year by year. To achieve high and stable potato yields, the following key cultivation points should be well managed:
I. Sowing period.Generally, sowing from mid-October to late November is more suitable. Too early and the high temperatures easily cause seed rot; too late and the late growth stage falls in the rainy season, making the plants prone to disease.
???II. Choosing varieties.Choose mainly potato varieties that suit local planting and consumption habits and offer high yield, drought tolerance, high-temperature tolerance, late blight resistance and good marketability. Examples include Favorita, Yueyin 85-38, Jinong 958 and others. After the previous crop is harvested, immediately plow deeply and harrow finely to ensure a loose soil layer of more than 25 cm. Form ridges and beds: bed surface width 90 cm, two rows per bed, furrow width 25 cm, bed height 25 cm.
III. Applying sufficient base fertilizer.Base fertilizer should account for more than 2/3 of the total fertilizer applied during the whole growth period, mainly organic fertilizer supplemented by chemical fertilizer, with nitrogen, phosphorus and potassium combined. Generally, per mu use 750-1000 kg of farmyard manure or burned soil, plus 300-500 kg of decomposed human and livestock manure, plus 30-40 kg of NPK compound fertilizer, 25-30 kg of superphosphate, and 10 kg of potassium chloride or potassium sulfate as base fertilizer.
??IV. Seed potato treatment.
1. Seed potato disinfection: Spread out the selected seed potatoes and spray them with a 200-fold dilution of 40% formalin or a 400-fold dilution of 75% chlorothalonil solution, then cover with plastic film for 2 hours, ventilate and air-dry (do not expose to strong sun), and store in a cool, dry place.
2. Seed potato cutting: Cut the seed potatoes one day before sowing. Before cutting, each person should prepare two cutting knives and sterilize them alternately with 75% alcohol or 0.5% potassium permanganate solution. When cutting, all the tuber flesh must be cut onto the seed pieces; do not merely bring the flesh near the eyes onto the piece while leaving the rest of the flesh behind, and never hollow out the seed piece into a small slice or small cone. Each seed piece should preferably weigh 50 g, with a minimum of no less than 30 g, and retain 1-2 eyes. Tubers of about 50 g need not be cut; those of 60-100 g are cut lengthwise from the top into two pieces; those of 110-150 g have the tail 1/3 cut off first, then are cut lengthwise from the top bud into 3 pieces; those above 160 g are cut lengthwise first and then crosswise.
???V. Sowing specifications.Generally, for a double-row bed of 85-90 cm, the row spacing within the bed is 25-30 cm, and the plant spacing is about 25 cm. Early-maturing varieties may be planted somewhat densely, and mid-to-late-maturing varieties somewhat sparsely. Open furrows for sowing, with a sowing depth of 5-6 cm. When sowing, avoid contact between seed potatoes and fertilizer, and at the same time sow seed pieces from the same part of the mother tuber or with similar sprout length in the same bed to facilitate uniform seedling management; place the sprout tip or eye upward, perpendicular to the horizontal plane. After sowing, cover with a thin soil layer of 5-6 cm, then cover the bed surface with rice straw.
???VI. Field management.
1. Early thinning of seedlings and intertillage earthing up: After the seedlings emerge uniformly, keep 1-2 strong seedlings per plant and remove excess weak seedlings, so as to promote strong seedlings, large tubers and high yield. Two earthings up are required during the whole growth period. The first is carried out when the seedlings are 10-15 cm tall, covering with 5-6 cm of soil, mainly to loosen the soil and control weeds; the second is carried out before the rows close, piling soil toward the seedling roots as much as possible, with wide earthing up and 3-4 cm of soil.
2. Early topdressing: Carry out the first topdressing when 70% of the seedlings have emerged, to promote strong seedlings and increase leaf area. After that, apply fertilizer once every 7-10 days, for a total of 4-5 topdressings by the time the stems and leaves close the rows. For the first, use 10-12 kg of compound fertilizer per mu plus 2-3 kg of urea, mixed with 1500-2000 kg of water and applied as a drench; for the second, use 7-10 kg of compound fertilizer per mu plus 2-3 kg of urea; from the third time onward, gradually reduce the amount of urea and add 2-3 kg of potassium chloride or potassium sulfate. At the same time, at the seedling stage, tuber formation stage and peak tuber bulking stage, spray a foliar fertilizer once each with a 500-fold dilution of "Yunda 120" or a 0.3% potassium dihydrogen phosphate solution, to regulate plant growth. One month before harvest, 1 g of "920" may be mixed with 75 kg of water and sprayed to extend the post-ripening period.
3. Management during the tuber formation stage: During tuber formation, avoid excessive vegetative growth. Especially during the tuber bulking stage, the demand for fertilizer and water is relatively high, and root uptake alone can no longer meet the plant's needs, so a mixed solution of 0.5% urea and 0.3% potassium dihydrogen phosphate or 0.8% potassium nitrate can be sprayed on the leaves, and the soil water-holding capacity should be maintained at about 80%. In addition, pay attention to supplementing magnesium fertilizer, that is, when the plants are 45 cm tall, apply 100 g of magnesium sulfate per mu mixed with 75 kg of water as a spray.