First, it is not easy to select varieties with strong winter varieties, such as Zhong Gan 11 and Chunfeng. Second, the appropriate sowing date sowing too early, when the seedlings are often too large, when the seedling stem diameter more than 6 mm, more than 7 leaves, the low temperature can be met by vernalization, prone to premature twitching. Therefore, sowing should be done in due course. Third, scientific management (a) seedling management. Precocious spring cabbage generally has a seedling age of 60 to 70 days, and the management of each period is mastered according to the seedling age. After sowing until the emergence of a higher temperature requirements, the daytime temperature is maintained at 20 °C ~ 25 °C, the night temperature is maintained at 15 °C. After the seedlings have been excavated, the daytime temperature is maintained at 20°C and the nighttime temperature is maintained at 13°C to prevent seedlings from growing. After transplanting, the daytime temperature was maintained at 15°C and the nighttime temperature was maintained at 10°C. Seedlings at night should pay attention to the temperature management at night, and should not be below 10°C for a long time. 7 days before planting, the seedlings can be practiced. The daytime temperature is maintained at 15°C and the nighttime temperature is maintained at 6°C to 8°C. The water should be controlled throughout the seedling stage. The seedlings should be irrigated during planting and transplanting. Afterwards, the water should be kept dry and not poured. The watering should be selected in the sunny morning. (b) Proper colonization. When the soil temperature at 5 cm depth is stable above 5°C, the temperature can be set at above 8°C. After the planting of seedlings, seedlings should also be properly planted. When the leaves start to cling, the seedlings should be stopped and timely irrigation and top dressing. (+)Sparteine Natural Sparteine,Plant Therapy Sparteine,Sparteine Cas 492-08-0,Sparteine Extract Powder Shaanxi The River Pharmaceutical Co., Ltd. , https://www.dahepharma.com