1. Seeding 1 seed selection Mainly choose high-quality and high-yield varieties, strong resistance, strong adaptability, good commodity, insensitive to long-term sunshine response. Jiangsu area mainly uses fine varieties such as Hongfei F1, Hongsheng F1 and Ziyang. 2 Sowing in time The selection of onion sowing time should be based on local temperature, light and ripeness of the selected varieties. The Jiangsu area is generally sown from September 10 to 20, with a seedling age of 50 to 60 days. 3 Seedbed preparation Seedbeds should be selected for plots with high topography, easy irrigation and drainage, and no onion or garlic planted for 2 to 3 years. After the previous crops are harvested, shallow tillage and fine rakes are applied in a timely manner, and sufficient base fertilizer is applied to make a flat border. Generally, 3,000 to 3,500 kg of decomposed high-quality organic fertilizer is applied to each seed bed, mixed with 50% phoxim emulsifiable concentrate 400 ml and wheat bran 6.5 kg, mixed well and mixed with organic fertilizer to control underground pests. Then turn the ground to mix the soil and fertilizer, rake thin, level, and make the border. 40～50 kg of diamine phosphate and 25 kg of potassium sulfate are applied per mu in the border. The seedlings are raised with high borders, with a border width of 1.2 m and a border width of 0.3 m. Do a good job after bordering, irrigate the bottom water, and sow after the water seeps down. Planting 1 mu of field onions requires seedlings of 60-75m2. 4 Sowing methods Before sowing, soak the seeds in 50℃ warm water for 10min; or use 50% Fumeishuang and 35% Metalaxyl wettable powders, and mix the seeds according to the seed weight 0.3%. Seeds are mixed with 3 to 5 times the fine soil, evenly spread on the border, and then covered with 0.8 to 1.5 cm thick fine dry soil, covered with plastic film on the border. The seeding amount of 1 m2 seed bed is generally controlled at 2.5～3.0g. 5 Seedling management Generally, seedlings start to emerge 7 days after sowing. After more than 60% of the seeds emerge, the plastic film is removed in the afternoon. Keep the seedling bed moist after sowing. When “drawing the bow†(the young stem grows to a length of about 4 cm, the cotyledons of the plant are arched and stretched tightly) and “stretching the waist†(the upper half of the cotyledon pulls the lower half and the seed coat out of the ground), There must be no shortage of water. Properly control water about 15 days before planting to promote root growth. Seedlings generally do not need top dressing. If the seedlings grow weaker, apply 5 kg of diammonium phosphate per mu of seedbed in combination with watering. 6 Strong seedling standard The standards for strong onion seedlings vary according to the variety and the season of seedling growth. Generally, the plant height is 15-18 cm, the pseudo-stem thickness is 0.6-0.8 cm, it has 3 to 4 leaves, the seedling age is 50 to 60 days, the plant is strong and free from diseases and insect pests. 2. Reasonable colonization 1 Fertilize, prepare the land, do the furrow For medium soil fertility, 3000-4000 kg of decomposed organic fertilizer per mu, 15-20 kg of diammonium phosphate, and 5-10 kg of urea are used as base fertilizers. After fertilization, flatten the rake and make it 1.5 to 1.8 m wide, flatten the flattened surface, pour enough water, use 72% metolachlor emulsifiable concentrate 50 ml or 33% pendimethalin emulsifiable concentrate 100ml per mu For 50 kg of water, spray the entire field to prevent and control weeds, and then cover with plastic film to compact it. 2 Colonization time The Jiangsu area is generally planted in mid to late November. 3 Colonization density The planting density of onions should be determined according to the variety, soil fertility and seedling size. Generally, the plant spacing is 15 to 16 cm, the row spacing is 15 to 18 cm, and 23 000 to 29 000 plants can be planted per mu. 4 graded seedling selection When planting, choose seedlings with well-developed roots, strong growth, and uniform size. After the seedlings are planted, classify them according to the size of the seedlings. Remove seedlings with diseased, weak, injured, and pseudo-stem diameters greater than 0.9 cm or less than 0.4 cm. Colonize separately. 5 Colonization methods Before planting, cut the roots of the seedlings to 2 cm, then dip the roots with 50% carbendazim 500-800 times solution. When planting, plant according to the size of seedlings. First plant holes according to plant and row spacing, and then plant seedlings into the planting holes. The planting depth should be such that the stem discs are buried and the leaf holes are not buried. 3. Field management 1 watering After the onion is planted, the planting water is poured immediately, and the planting is overwintering. The temperature is low and the growth is slow. The irrigation should be properly controlled. The main cultivation is to protect the soil moisture. The frozen water is poured once before the soil is frozen. After returning to the green in the second year, pour back the green water in time to promote the growth of the seedling. Watering in the early growth period of leaf spring should not be too diligent. Keep the soil dry and wet. Generally, water once every 7 to 10 days. When the bulb begins to swell, the squat seedlings should be properly controlled with water for about 10 days. After squatting the seedlings, the bulbs start to swell, which is the key period for top dressing and irrigation. It should be watered frequently, and it is better to irrigate sooner or later. Stop watering 8 to 10 days before harvest. 2 Fertilization According to soil fertility and growth conditions, top dressing in stages. When returning to green, apply 10 to 15 kg of ammonium sulfate and 20 to 30 kg of superphosphate per mu per mu. After returning to green, the plant enters Ye Wangsheng growing season for the second top dressing, with 15-20 kg of ammonium sulfate applied per mu. 50 to 60 days after returning to green, 10 kg of ternary compound fertilizer of nitrogen, phosphorus and potassium was applied topped with water at the expansion stage of bulb, and applied again at intervals of 15 to 20 days. Bulbs are in full bloom and fertilize as needed. The last time of top dressing should be more than 30 days from the harvest period. 3 Picking buds and sprouting The onion bolting phenomenon often occurs during the growth of spring. On the production side, the methods of picking buds and splitting bolts are often used to promote the differentiation of lateral buds and obtain some yield. According to the experience of some vegetable farmers in Shandong and Tianjin, it is better to remove the buds at the top of the flower stems in the early stage to avoid nutrient waste. There is also the splitting method, which splits the flower sedge in half from top to bottom to promote the growth of lateral buds, squeeze the stalk stem to the side, and finally form a fuller bulb. Jishan Huayao 4. Disease and Pest Control In accordance with the plant protection policy of "prevention first, comprehensive prevention and control", agricultural prevention, physical prevention, and biological prevention methods are given priority, and chemical prevention techniques are used scientifically and rationally. Use 75% chlorothalonil wettable powder 500 times liquid or 70% mancozeb 500 times liquid or 58% metalaxyl manganese zinc 500 times liquid during growth to prevent purple spot disease, use 72% manganese zinc · cream urea wettable powder 600 times liquid or 64% um cream·manganese zinc wettable powder 600～800 times liquid to prevent downy mildew, use 40% pyrimethanil emulsifiable concentrate 1000 times liquid or 40% gray mold sclerotium net suspension agent 1 200 times liquid to prevent gray mildew. In the early peak period of Liriomyza sativae adults and the peak period of larval leaf damage, it is controlled with 1.8% avermectin emulsifiable concentrate 2000-3000 times solution or 75% desfluramine wettable powder 3000 times solution. Disclaimer: Some articles of this website are transferred from the Internet. 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