Jiaozhou native Chinese cabbage Jiaozhou has been planting Chinese cabbage for more than 400 years. Jiaozhou Chinese cabbage is characterized by large bundles of thin, tightly rolled, less fiber, white and sweet juice, rich nutrition, refreshing raw food and poor taste when eaten hot. Jiaozhou Chinese cabbage enjoys a good reputation at home and abroad, and is known as "glue white". This vegetable is resistant to storage and easy to preserve, and it is the main vegetable of Qingdao people in winter and spring. Fan Chengda, a poet in the Song Dynasty, once wrote a poem in "Pastoral Miscellaneous Xing", "You must taste the honey lotus root when you pull out the snow." Chinese cabbage, the "king of ten thousand kinds of vegetables" here, is widely planted in China, but it is prone to bolting, summer rot, diseases and serious pests when planted in spring. In order to solve these problems, the author, on the basis of summarizing other people's experience and combining with the local actual situation, now introduces the cultivation techniques as follows: 1, selects suitable varieties, and selects Korean "Spring and Summer King" Chinese cabbage varieties as sowing dates. This variety is not sensitive to low temperature, not easy to vernalization and premature bolting. Through the investigation on the actual growth of three different treatments in the field around April 10 and around April 20, after June 1 sowing and direct seeding in the open field at the beginning of May, it was found that few plants were planted in May 10 except for cold bed seedling on April 8. 2. Determine the suitable seedling age. Generally, Chinese cabbage leaves are composed of 35-70 leaves. When 8 true leaves are unfolded, the differentiation of these leaf primordia is completed. It takes about 1 month for 8 true leaves to unfold in spring. If the seedling stage is too long, the survival rate of planting in the field will decrease; If the leaf transplantation is insufficient, it will affect the differentiation of leaf buds, leading to the premature formation of flower buds and bolting. After sampling 30 plants, the number of leaves of "Chunxiawang" variety is between 48 and 59. This not only avoids the decline of survival rate caused by too long seedling period, but also avoids the influence of too short seedling period on the number of fully differentiated leaves. 3. Strengthening field management Field management of spring-sown Chinese cabbage is different from autumn cultivation, and the word "guarantee" is emphasized throughout the whole process. 3. 1 The soil configuration of seedbed emphasizes "fat", "warm", "fine" and "loose". The formula of 2/3 non-cruciferous garden soil, 1/3 decomposed manure and 0.2% diammonium nutrient soil laid a good foundation for cultivating strong seedlings. 3.2 When planting, all plants are covered with plastic film. Apply 4000 kilograms of farm manure per mu, diammonium 15 kilograms, and the row spacing is 0.5× 0.4 meters. 3.3 After planting water, water the seedlings immediately when the ground is wet and dry. Don't squat during the whole growth process. Keep the fields moist and dry. After planting 1 month, topdressing urea 1 time, per mu10-15kg. 4. Pest control According to the investigation of this experiment, soft rot only occurred slightly in the first stage (seedling raising on April 8, sowing in May 10), and this phenomenon was almost absent in the second and third stages. Spraying streptomycin 1.50 mg/kg for control. The incidence of downy mildew showed a trend of heavy before and light after. Use 600-800 times of mancozeb solution or 400 times of propargite solution for prevention and control. 5, timely harvest