Cultivation techniques of Artemisia annua in greenhouse in early spring

It is better to select varieties with strong cold resistance, and it is generally necessary to use 1.5-2kg per mu. Three to five days before sowing, the seeds were soaked in warm water of 30 ℃ for 24 hours. After washing and drying, they were placed under the condition of 15: 20 ℃ to accelerate germination. The seeds were washed with warm water once a day, and the seeds could be sown after germination. Fertilization and soil preparation combined with the application of diammonium phosphate 20kg / mu, potassium sulfate 10kg / mu, ammonium bicarbonate 25kg, deep turning and leveling to form a flat border with a width of 1.5m. There are two reasonable sowing methods: ① sowing watering in the border, sowing seeds evenly after water infiltration, covering soil 0.5cm thick. ② strips were planted in the border and ditched at a row spacing of 15 cm to 20 cm, with a depth of 0.5 cm. After watering in the ditch, the strips were sown with seeds, and then covered with soil. Strengthen management and keep the temperature at about 20: 25 ℃ during the day and 10 ℃ at night after sowing. The suitable time for seedling emergence is 15: 20 ℃ in daytime and 8: 10 ℃ at night. When the seedlings grow to 1 × 2 leaves, the seedlings should be kept between 4 × 4 cm, and the seedlings should be thinned and over-dense properly. Start watering when the seedling height is 3 centimeters, and fertilize with water when the seedling height is about 10 centimeters, and use ammonium sulfate 10 to 15 kilograms per mu. Combined with watering and topdressing for 1 and 2 times, 600 times of cytokinin was sprayed reasonably to improve the yield and quality. For pest control, such as leaf blight and downy mildew, spray control such as 72.2% Pulek or 72% or 800 times Kelu can be selected.