The broccoli planting has a high economic benefit and is widely planted in the Nanmazhuang Special Vegetable Base in Yongnian County. However, a few days ago, some farmers reported that the quality of the broccoli they planted was poor and their production was about 50% lower than in previous years. After the on-site investigation, it was discovered that the broccoli occurred in early twitches. Broccoli is a long-term low-temperature crop. The vernalization effect is not strict with the low temperature. After the seeds germinate, they can experience low temperatures. However, the vernalization is quite different due to different varieties. For early maturing varieties, the diameter of the seedling stems is required to be 3.5 mm, vernalization is completed at 20° C. for 10 days at 10° C.-17° C., and the diameters of medium-maturing varieties and seedling stems are to be 10 mm, and the temperatures are 5° C.-10° C. The vernalization is completed in a day; the late-maturing varieties require the seedling stems to have a diameter of 15 mm, and vernalization is completed at 50C for 2 days at 2°C to 5°C. Varieties that are ripe early can easily complete vernalization, and early bolting can occur. For example, mid-maturing varieties should be suitable for winter and spring cultivation. The temperature management should be strengthened during the nursery period. After sowing, the bed temperature was controlled at 23°C-25°C; the temperature was lowered slightly after emergence, kept at 15°C-18°C during the day, not higher than 25°C, and not lower than 10°C at night. For early maturing cultivars, the seedling temperature is not less than 12°C for a long period of time. Generally, it will not pass through the vernalization prematurely, causing early seizures. Within one week after planting, the temperature in the protected area shall be raised, and the requirement shall be around 30°C during the day and not less than 18°C ​​during the night so as to facilitate the easing of seedlings. Broccoli grows vigorously, hi fat, hi moist, must apply enough basal fertilizer, ensure top dressing, do enough fertilizer, in order to obtain high yield and high quality. In short, the focus must be taken to avoid low seedling temperature and prevent broccoli seedlings from passing vernalization prematurely, causing early convulsions. Hair Rejuvenation Laser Helmet,Hair repair device,Anti-hair Loss Laser Hair Growth Cap,Laser Medical Hair Loss Laser Cap Shenzhen Guangyang Zhongkang Technology Co., Ltd. , https://www.szlighttherapymachine.com