Key Field Management Techniques for Winter-Grown Potatoes in Huizhou
Field Management Techniques for Winter-Grown Potatoes in Huizhou
I. Scientific Fertilization
The fertilization principles are: apply sufficient base fertilizer, apply topdressing early, and increase potassium fertilizer. Give priority to organic fertilizer with chemical fertilizer as a supplement; give priority to base fertilizer with topdressing as a supplement; apply nitrogen fertilizer moderately and increase potassium fertilizer.
1. Base fertilizer
The base fertilizer should account for more than 60% of the total fertilization for the whole period, mainly consisting of decomposed organic fertilizer. Generally, apply 300-400 kg of chicken manure per mu or 800-1000 kg of other poultry and livestock manure, add 25-30 kg of superphosphate, mix well and compost until decomposed (about 15 days), then add 25 kg of compound fertilizer (with nitrogen, phosphorus and potassium content each at 15%, the same below), 5-7.5 kg of potassium sulfate or potassium chloride, 2 kg of borax, and 3 kg of trichlorfon powder, mix evenly, open a fertilization furrow 5 cm deep in the middle of the ridge during land preparation, and cover with soil after application.
2. Topdressing
Topdressing is generally applied 3 times, with each application interval of 7-10 days. In the early stage, nitrogen fertilizer is mainly applied to promote early and rapid growth of seedlings; in the later stage, potassium fertilizer should be increased to promote tuber enlargement. The 1st topdressing is the seedling-promoting fertilizer applied when 80% of seedlings have emerged, with 5 kg of compound fertilizer and 3-4 kg of urea per mu; the 2nd is the plant-developing fertilizer applied at the 6-8 leaf stage, with 7.5 kg of compound fertilizer and 3-4 kg each of urea and potassium sulfate or potassium chloride per mu; the 3rd is the plant-strengthening and tuber-bulking fertilizer applied at the 10-12 leaf stage or when tubers are the size of a chicken egg, with 8-10 kg of compound fertilizer and 5 kg of potassium sulfate or potassium chloride per mu. Each topdressing should be dissolved in 2000-2500 kg of water per mu and applied as a drench. After the 3 topdressings, spray the foliage 1-2 times with 0.2% "Yunda 120" + 0.3% monopotassium phosphate solution.
II. Chemical Weed Control
After sowing and before emergence, spray 40-80 ml of 96% S-metolachlor per mu diluted in 75 kg of water onto the ridge surface, or before the 1st hilling, use paraquat for directed spraying on the ridge surface, but take care to avoid spraying on stems and leaves as much as possible.
III. Intertillage and Hilling
Perform intertillage and hilling 2 times throughout the period to prevent tubers from being exposed and reduce green-headed tubers. Generally, after the 2nd topdressing, carry out small hilling in a timely manner, with a soil thickness of 3-4 cm, covering all the rice straw; after the 3rd fertilization, combine with weeding to carry out large hilling, with a soil thickness of 5-6 cm. During hilling, try to avoid damaging stems, branches and leaves.
IV. Appropriate "Running Horse Water" Irrigation
Actively promote water-saving irrigation techniques. During the germination stage, potatoes can generally rely on the water supply from the seed tubers themselves to ensure emergence. During the seedling stage, the water requirement is relatively small, and the water needs for seedling growth can basically be met through drenching with water and fertilizer. Therefore, before the plant-developing stage, irrigation is generally not carried out, which helps save water, promote deep rooting of seedlings, and improve drought resistance. After entering the plant-developing stage, the water requirement of the plants increases, reaching its maximum before the tuber-setting stage (from the beginning of flowering to 7 days after flowering), and decreases in the later part of the tuber-setting stage. Therefore, after small hilling and large hilling, and at the bud stage, if there is no rain, apply 1 "running horse water" irrigation each time. In the later stage, if there is no rain for a long time and the soil is too dry, continue to apply 1-2 "running horse water" irrigations. Note that each "running horse water" irrigation should only fill to 1/2 the height of the furrow, and should be drained within 1 hour, leaving no standing water at the bottom of the furrow. After moderate to heavy rain, irrigation should not be carried out, and accumulated water in the furrow should be drained promptly to prevent tuber rot and the spread of diseases.
V. Timely Prevention and Control of Pests and Diseases
Potatoes have many pests and diseases. The key focus should be on the prevention and control of blackleg, late blight, ring rot, bacterial wilt, aphids, cutworms, potato tuber moths and other pests and diseases. For prevention and control: First, promote disease-resistant varieties, select virus-free seed potatoes and carry out strict disinfection; second, when applying base fertilizer or the 1st and last drenching with water and fertilizer, add 3 kg of trichlorfon powder per mu respectively and mix (drench) to prevent underground pests; third, after large hilling, spray the foliage 1-2 times with Ridomil or 58% Gold Ridomil at 600 times plus 72% agricultural streptomycin at 4000 times to prevent late blight, bacterial wilt, etc.; fourth, rationally apply fertilizer and water, avoid water accumulation in the field, and prevent excessive vegetative growth; fifth, strengthen field inspection and apply targeted pesticides promptly when pests and diseases are found.
VI. Timely Harvest
Harvest around the physiological maturity stage of potatoes, that is, when plant growth stops, most stems and leaves turn yellow and withered, and tubers are easily separated from stolons. This is the physiological maturity stage with the highest yield. Seize the market maturity stage when market prices are highest to harvest and supply the market in a timely manner, so as to maximize actual benefits.
The fertilization principles are: apply sufficient base fertilizer, apply topdressing early, and increase potassium fertilizer. Give priority to organic fertilizer with chemical fertilizer as a supplement; give priority to base fertilizer with topdressing as a supplement; apply nitrogen fertilizer moderately and increase potassium fertilizer.
1. Base fertilizer
The base fertilizer should account for more than 60% of the total fertilization for the whole period, mainly consisting of decomposed organic fertilizer. Generally, apply 300-400 kg of chicken manure per mu or 800-1000 kg of other poultry and livestock manure, add 25-30 kg of superphosphate, mix well and compost until decomposed (about 15 days), then add 25 kg of compound fertilizer (with nitrogen, phosphorus and potassium content each at 15%, the same below), 5-7.5 kg of potassium sulfate or potassium chloride, 2 kg of borax, and 3 kg of trichlorfon powder, mix evenly, open a fertilization furrow 5 cm deep in the middle of the ridge during land preparation, and cover with soil after application.
2. Topdressing
Topdressing is generally applied 3 times, with each application interval of 7-10 days. In the early stage, nitrogen fertilizer is mainly applied to promote early and rapid growth of seedlings; in the later stage, potassium fertilizer should be increased to promote tuber enlargement. The 1st topdressing is the seedling-promoting fertilizer applied when 80% of seedlings have emerged, with 5 kg of compound fertilizer and 3-4 kg of urea per mu; the 2nd is the plant-developing fertilizer applied at the 6-8 leaf stage, with 7.5 kg of compound fertilizer and 3-4 kg each of urea and potassium sulfate or potassium chloride per mu; the 3rd is the plant-strengthening and tuber-bulking fertilizer applied at the 10-12 leaf stage or when tubers are the size of a chicken egg, with 8-10 kg of compound fertilizer and 5 kg of potassium sulfate or potassium chloride per mu. Each topdressing should be dissolved in 2000-2500 kg of water per mu and applied as a drench. After the 3 topdressings, spray the foliage 1-2 times with 0.2% "Yunda 120" + 0.3% monopotassium phosphate solution.
II. Chemical Weed Control
After sowing and before emergence, spray 40-80 ml of 96% S-metolachlor per mu diluted in 75 kg of water onto the ridge surface, or before the 1st hilling, use paraquat for directed spraying on the ridge surface, but take care to avoid spraying on stems and leaves as much as possible.
III. Intertillage and Hilling
Perform intertillage and hilling 2 times throughout the period to prevent tubers from being exposed and reduce green-headed tubers. Generally, after the 2nd topdressing, carry out small hilling in a timely manner, with a soil thickness of 3-4 cm, covering all the rice straw; after the 3rd fertilization, combine with weeding to carry out large hilling, with a soil thickness of 5-6 cm. During hilling, try to avoid damaging stems, branches and leaves.
IV. Appropriate "Running Horse Water" Irrigation
Actively promote water-saving irrigation techniques. During the germination stage, potatoes can generally rely on the water supply from the seed tubers themselves to ensure emergence. During the seedling stage, the water requirement is relatively small, and the water needs for seedling growth can basically be met through drenching with water and fertilizer. Therefore, before the plant-developing stage, irrigation is generally not carried out, which helps save water, promote deep rooting of seedlings, and improve drought resistance. After entering the plant-developing stage, the water requirement of the plants increases, reaching its maximum before the tuber-setting stage (from the beginning of flowering to 7 days after flowering), and decreases in the later part of the tuber-setting stage. Therefore, after small hilling and large hilling, and at the bud stage, if there is no rain, apply 1 "running horse water" irrigation each time. In the later stage, if there is no rain for a long time and the soil is too dry, continue to apply 1-2 "running horse water" irrigations. Note that each "running horse water" irrigation should only fill to 1/2 the height of the furrow, and should be drained within 1 hour, leaving no standing water at the bottom of the furrow. After moderate to heavy rain, irrigation should not be carried out, and accumulated water in the furrow should be drained promptly to prevent tuber rot and the spread of diseases.
V. Timely Prevention and Control of Pests and Diseases
Potatoes have many pests and diseases. The key focus should be on the prevention and control of blackleg, late blight, ring rot, bacterial wilt, aphids, cutworms, potato tuber moths and other pests and diseases. For prevention and control: First, promote disease-resistant varieties, select virus-free seed potatoes and carry out strict disinfection; second, when applying base fertilizer or the 1st and last drenching with water and fertilizer, add 3 kg of trichlorfon powder per mu respectively and mix (drench) to prevent underground pests; third, after large hilling, spray the foliage 1-2 times with Ridomil or 58% Gold Ridomil at 600 times plus 72% agricultural streptomycin at 4000 times to prevent late blight, bacterial wilt, etc.; fourth, rationally apply fertilizer and water, avoid water accumulation in the field, and prevent excessive vegetative growth; fifth, strengthen field inspection and apply targeted pesticides promptly when pests and diseases are found.
VI. Timely Harvest
Harvest around the physiological maturity stage of potatoes, that is, when plant growth stops, most stems and leaves turn yellow and withered, and tubers are easily separated from stolons. This is the physiological maturity stage with the highest yield. Seize the market maturity stage when market prices are highest to harvest and supply the market in a timely manner, so as to maximize actual benefits.