How to prevent early Chinese cabbage from being unprotected?

When Chinese cabbage was planted early, it often had only long leaves, no heart, small vegetable balls and low yield. the main reasons were high weather temperature, too much Rain Water, or rapid soil water loss, and serious damage to diseases and pests, especially soft rot, dry heart disease, downy mildew, powdery mildew, virus diseases, aphids, cabbage green insects and so on. In addition, improper fertilization, such as excessive nitrogen fertilizer, insufficient phosphorus and potassium fertilizer and uneven water supply, are also important reasons for the lack of care in Chinese cabbage. If the following technical measures are taken to strengthen the management, it can be promoted to keep the ball in mind. After 25 days of planting of Chinese cabbage, phosphorus and potassium fertilizer was applied once every 10 to 15 days, 25 ~ 30 grams of potassium dihydrogen phosphate per plant (sprinkled with clear water), or diluted with retting mature human and animal manure water into 80 times 100 times, and then applied continuously for 3 times. Spraying foliar fertilizer from the time when Chinese cabbage began to heart and bear balls, 0.3% potassium dihydrogen phosphate, 500x Zhuangfengyou and 1500 times Shennong chelate fertilizer mixture were sprayed on the leaves every 7 to 10 days, and were sprayed 3 times in a row for 5 times to wet all leaves evenly, so that it was appropriate to start dripping. To prevent water shortage during the growth of Chinese cabbage, we must ensure an adequate water supply, avoid more and less, sometimes dry and wet, so as to prevent the leaves of Chinese cabbage from curling and wilting; when the weather is dry, in addition to dripping water once in the morning and evening, 1.5 kilograms per plant, cover the border with wheat straw or other weeds to reduce water loss and keep the soil moist. Pest control Chinese cabbage is harmed by virus diseases, soft rot, hanging filariasis, aphids and other diseases and insects, which will cause no care and no heading. Therefore, during the heading period of Chinese cabbage, we should pay attention to check the leaves. If diseases and insect pests are found, the mixture of 1500 times of Nongdile and 1500 times of Dysenamine should be sprayed continuously for 3 times, or the mixture of 1500 times of Lexbene and 1000 times of Shoude should be sprayed for control. If the soft rot is seriously harmful, 500 times agricultural streptomycin should be added.