Artemisia annua L. and its cultivation techniques in greenhouse

Chrysanthemum belongs to semi-cold-resistant vegetables, like cold and humid climate, growth temperature is 18-20℃, growth is poor above 29℃, growth is slow below 12℃, can tolerate short time. Low temperatures around 0 ° C. The light requirements are not strict, more resistant to weak light, is a long-day crops. If the temperature can be controlled, it can be planted in the greenhouse. Select land. The height of the stem can reach 20-30 cm during the vegetative growth period, so it can be planted in the south low part of the greenhouse where high-seedling crops (such as kidney beans, tank beans, etc.) are planted. Select the species. Chrysanthemum has two kinds of big leaf varieties and small leaf varieties, and small leaf varieties are mainly used in greenhouse cultivation. Small leaf varieties are more cold-resistant, with a growth period of 40-50 days. Cultivation techniques. Cultivation of chrysanthemum requires that the soil be kept moist frequently. In order to separate from the planting beds of high-seedling crops, the beds for planting chrysanthemum should be made into independent flat beds for watering. In order to promote emergence, seed soaking and germination can be carried out, and wet method for strip planting or broadcast. After sowing, cover with soil 1 cm, tightly cover with plastic film. Usually 4-5 kg per mu. After emergence, remove all plastic films, keep the ridge surface dry and wet for 1-2 true leaves, thin seedlings and pull out weeds, and keep the seedling spacing about 4 cm. Pay attention to regular observation of humidity in the shed, so as to avoid excessive moisture, resulting in the occurrence of diseases of high-seedling crops in the shed. During the growth period, quick-acting nitrogen fertilizer is applied for 1-2 times with water. When the plant reaches about 20 cm, harvest is started, not too late, so as not to affect the quality. After the first cut, water and topdressing are applied to promote the occurrence of lateral branches, and harvest is carried out after 20-30 days. The topdressing amount per mu is 10 kg urea each time.