How to plant broccoli in winter

Broccoli, also known as broccoli and green cauliflower, is fed by flower heads composed of fleshy, fat and tender branches with complete nutrients and high nutritional value; broccoli likes warm and cool climate, humid environment, avoid inflammatory heat, drought, and is not resistant to frost; the optimum temperature for seed germination is 15 ℃ 30 ℃, the optimum temperature for plant growth is 20 ℃, and the optimum temperature for flower ball formation is 1518 ℃, with dysplasia above 25 ℃. It is easy to cultivate, and it is an excellent vegetable species to make full use of winter fallow land after late rice harvest. First, to sow winter broccoli, we should first select varieties with wide applicability and strong cold tolerance, sow them on a pre-prepared seedbed, or raise seedlings in a nutrition bowl. The seeding rate is 20ml / mu and 25g / mu. After sowing for 30 days, the seedlings can be planted when they have 5m / m 6 true leaves. Spraying insecticidal and seedling-killing agents on the seedbed before planting. Second, ploughing and soil preparation for 10 days before planting and planting, ditching and deep application of base fertilizer. The amount of base fertilizer used is 2500 kg of rotten pig and cow manure and 25 kg of compound fertilizer per mu. After soil preparation, the border is in the south-north direction, generally covering the ditch of 1-1.2 meters in double rows, with a height of 15 mi 25 cm. The planting row spacing is 45 cm × 60 cm, and there are about 2500 seedlings per mu. Third, field management 1, watering: broccoli avoid hot, dry, generally 5mi 7-day watering, to be thoroughly watered. 2. Topdressing: 10 kg urea per mu after 20 days of planting, 10 kg of urea per mu when the plant has 15 leaves, 10 kg of urea per mu when the plant has 15 leaves, and 5 kg of urea, 30 kg of calcium magnesium phosphate and 50 kg of potash fertilizer when the plant has 21 leaves. 2Mel was sprayed with 0.1% borax for 3 times during pilling. After the flower head is harvested, the varieties with strong germinating ability of opposite lateral branches need to continue to be fertilized and watered. Each time the lateral flower heads were harvested and fertilized once. 3. Ploughing and sprouting: loosen the soil and weed before fertilization, and cultivate the soil after fertilization. For the special varieties of the main bulb, the lateral buds should be erased before the main bulb is harvested, and the varieties of the main and lateral bulbs should be selected to keep 4 strong lateral branches to erase the thin and weak lateral branches. 4. prevention and control of diseases and insect pests: check in the field frequently and prescribe the right medicine when diseases and insect pests are found. The main diseases are soft rot, Sclerotinia sclerotiorum, aphids, cabbage insects and so on. Fourth, after the flower bulb of broccoli harvest is mature, the suitable harvest time is when the bud particles are slightly loosened. During the high temperature period, it should be harvested 2 days earlier and cut off together with the flower stem when harvesting.