Practical Tips for Potato Planting, Management and Harvesting

(1) Site selection and fertilization

Choose deep, loose, fertile sandy loam soil, plow and break up the soil, level it, and then cultivate. Potatoes need a relatively large amount of fertilizer in the early and middle growth stages. To ensure normal growth and development, a heavy base fertilizer must be applied. Generally, apply 2500-3000 kg of farmyard manure, 50 kg of phosphate fertilizer, and 15 kg of potassium fertilizer (or 100-200 kg of plant ash) per mu. After thorough mixing, apply in holes or furrows at transplanting.

(2) Sowing

1. Choose improved varieties: It is advisable to choose varieties with high yield, good quality, strong disease resistance, and suitability for local planting, especially virus-free potatoes as the first choice.

2. Sow at the right time: For spring planting, generally about one month before the late frost, when the outside temperature is stable above 5°C, sowing can begin. In areas where the purpose is to grow commercial potatoes, on the principle of avoiding damage from late frost, strive to sow early at the right time to bring them to market earlier. The specific sowing time should be determined according to local microclimate conditions.

3. Seed potato treatment: To prevent infection carried by seed potatoes, before sowing it is best to soak them in 0.3-0.5% formalin for 20-30 minutes, then take them out and seal them in a plastic bag or airtight container for about 6 hours, or soak them in 0.5% copper sulfate solution for 2 hours for disinfection. At sowing, to prevent delayed emergence due to the seed potatoes not having passed dormancy, soak them in 2-3 ppm gibberellin solution for 5-10 minutes, or soak them in 0.5% lime water for 1-2 hours to break dormancy.

4. Sowing density and depth: Potatoes are mostly planted in a two-row relay intercropping system with corn, generally at a suitable density of 3000-3200 plants per mu, with row spacing of 1-1.2 chi and hole spacing of 7-8 cun. It is best to use small whole seed potatoes of 20-25 grams for sowing. If the seed potatoes are too large, they should be cut into pieces for planting, with cut pieces kept at 20-25 grams, and the cut surfaces disinfected properly, keeping the sowing rate at 60-80 kg. For pure cropping, maintain a planting density of 3600-4200 plants per mu, with a sowing rate of about 100 kg. The suitable sowing depth is 10-15 cm. A suitable sowing depth can prevent frostbite or sunscald of the tubers, increase the number of tuber-bearing layers, and help improve yield and quality.

(3) Field management

1. Cultivation and hilling: While removing field weeds, this can thicken the soil layer, raise soil temperature, increase the soil range for tuber growth, and increase underground stems and roots, playing an important role in increasing yield. Generally, cultivation and hilling should be carried out once in mid-to-late April and once from May to early June. Cultivating and hilling in the early growth stage of potatoes can raise soil temperature and promote sprouting and growth; cultivating and hilling in the middle and late stages can enhance soil permeability and help tubers expand.

2. Reasonable topdressing: Potatoes grow relatively fast. In addition to applying sufficient base fertilizer, attention should also be paid to topdressing to promote robust growth. Generally, topdress 2 times, in combination with cultivation and hilling. The first time should focus on nitrogen fertilizer, applying 10 kg of urea per mu, or about 25 loads of human manure and urine per mu, with each load mixed with 100 grams of urea for watering. The second time should focus on phosphate and potassium fertilizers, applying 20-25 kg of phosphate fertilizer and 5-10 kg of potassium fertilizer (or 100 kg of plant ash) per mu.

3. Flower removal and branch thinning: Potatoes have strong branching ability. If planted too densely or with too much nitrogen fertilizer, excessive growth and overly high density will affect underground development. Branches should be thinned in time, removing diseased and weak branches, enhancing ventilation and light penetration, and reducing disease. During the bud formation stage, remove flower buds in time to avoid nutrient consumption, promote concentrated nutrient supply to the tubers, and increase yield.

4. Pest and disease control: The main pests and diseases that cause serious damage to potatoes include late blight, viral diseases, potato tuber moth, and aphids. A prevention-first policy should be adopted, with active integrated control, such as selecting disease-resistant varieties and rational pesticide use. About 20 days after transplanting, apply 15-20 kg of urea per mu mixed with clear manure water for drenching; at the bud and bolt stage, apply 10-15 kg of urea and 5-10 kg of potassium chloride per mu, using a transplanter to make holes for hole application; at the early flowering stage and full flowering stage, spray leaves with 0.5-1 kg of urea, 0.15-0.2 kg of monopotassium phosphate, and 0.15-0.2 kg of borax mixed with 45-60 kg of water per mu each time.

Pest and disease control measures: Before the seedling stage (before the rosette stage), focus on controlling aphids, cabbage caterpillars, leafminers, and downy mildew; at the bud and bolt stage, focus on controlling downy mildew; at the early flowering stage, focus on controlling sclerotinia; at the pod-setting stage, pay attention to controlling aphids. When using pesticides, choose high-efficiency, low-toxicity, low-residue pesticides.

(4) Timely harvesting

About 30 days after the final flowering, when two-thirds of the whole plant's siliques are yellow-green, the siliques at the base of the main inflorescence are loquat-colored, and the seed coat is dark brown or yellow, it is the suitable harvest period, that is, "harvest at 80% maturity for a full 100% yield," and it should be harvested in time.