Management measures of rosette stage of Chinese Cabbage

First, fertilizer and water management Chinese cabbage rosette stage, the growth rate and growth are very fast, the amount of fertilizer required increased. At the initial stage of the rosette, the "hair" fertilizer should be applied with 8-10 kg of urea per mu. The method is to open a 10 cm ditch on one side of the ridge, fertilize and close the ditch and water it. When opening the ditch, pay attention to hurt the root as little as possible. Second, squatting seedlings to promote root Chinese cabbage squatting seedlings by controlling watering from mid-rosette to heading stage, controlling vigorous growth, thickening leaves, promoting root development, conducive to nutrient accumulation, reducing field humidity, and controlling the occurrence and development of diseases. The squatting time varied from 10 to 20 days, and the leaf color changed from green to yellow or wilted slightly at noon. There are less squatting seedlings in the following situations: varieties with short growth period and fast growth, sowing too late, transplanting large seedlings, poor seedling condition, drought, less rain, higher temperature and lack of water, fertilizer and sand. Third, the main diseases in rosette stage of Chinese cabbage are downy mildew and soft rot. Prevention and control methods: one is to control humidity to prevent downy mildew and soft rot. The second is to find the disease, timely use of drugs to control the development of the disease.