Key points of cultivation techniques of cabbage in spring

1. Timely sowing and timely sowing is one of the important technical measures for spring cabbage cultivation. If the sowing is too early, the seedling growth is larger, and the continuous low temperature in early spring makes the seedlings pass through the vernalization stage prematurely, and early bolting is easy to occur. On the contrary, the sowing is too late and the mature period is delayed, which affects the economic benefits. Hangzhou area generally carries out protected sowing and seedling raising from mid-late February to mid-March, and dry seed sowing. The seedbed was watered before sowing and covered with fine soil after sowing, which was about 1 inch thick. the sowing amount was about 25g seeds per mu of field. 2. Management of seedling stage in order to cultivate strong seedlings, temperature management at seedling stage is very important. After sowing, the temperature is controlled at 20-25 ℃ during the day and 10 ℃ at night. If you encounter low temperature, you need to cover the grass curtain at night, and the temperature can be reduced appropriately after the seedlings come out, no matter in sunny or rainy days. After emergence, the disease and insect pests were prevented and treated in time, Haizheng Chongling was used to control Plutella xylostella, and Luheng No. 1 was sprayed to prevent cabbage sudden collapse. The standard of strong seedlings is dark green leaves, thick and large leaves, stout stems, short internodes, well-developed roots and disease-free seedlings. 3. According to the climatic conditions in Hangzhou, it is generally planted to the field in the first and middle April, when the seedlings have 6-7 leaves, and apply sufficient basic fertilizer 10 days before planting. Generally, 75 kg of n, p, k ternary compound fertilizer and 35 kg of phosphate fertilizer are applied per mu. After fertilization, combined with ditching and border covering soil, the width of the border is 1.2m, the row spacing of planting plants is 40 × 50cm, and the seedlings are protected by 3000-3200 plants per mu. 4. watering in time after field management and planting, in order to improve the survival rate of seedlings, clear ditches and drainage during the growth period, and keep the root system developing well. Timely use of Haizheng insecticidal spray to prevent the harm of cabbage insects. In the rosette stage, fertilizer should be applied in time to promote the rapid expansion of the leaf bulb, and the fertilization should be stopped one month after the rosette stage. 5. The harvest is generally in the first and middle of June, when the leaf ball is fully grown and tight, and the ball weighs 1.5-2 years. It can also be harvested according to the market situation. If the vegetable price is low at this time, the harvest can be delayed.