How to prevent early bolting of Angelica sinensis?

How to prevent early bolting of Angelica sinensis? Please introduce the method of Angelica sinensis, which is native to alpine mountain area and is a plant with low temperature and long sunshine. In ontogeny, vegetative growth to reproductive growth needs to go through two stages: vernalization stage (low temperature of 0 ℃) and light stage (long sunshine for more than 12 hours). Therefore, artificial cultivation requires growing seedlings in the first year, harvesting roots for medicine in the second year, and bolting and flowering and fruiting in the third year. However, in production practice, Angelica often bolts and blossoms in June and July in the second year of cultivation, and the bolting rate in normal years is between 10% and 30%, and when it is serious, it is more than 60%. In bolting and flowering plants, the parenchyma cells of secondary xylem are lignified, the ratio of secondary phloem to secondary xylem changes from the normal 2:1 to 1:10, the fleshy root is gradually xylem and hollow, firewood is large, lack of oil and gas, and can not be used medicinally. Therefore, preventing and controlling early bolting is an important technical measure to improve the yield and quality of Angelica sinensis. According to the factors affecting bolting and flowering of Angelica sinensis, attention should be paid to: 1. Selection and retention of improved varieties. Under the same cultivation conditions, the seeds of early bolting and flowering plants generally have the character of early maturity and are easy to bolting and flowering. According to the experiment, under the same conditions of seedlings and cultivation and management measures, the seedlings were raised with seeds flowering and fruiting in the second year and the third year, respectively. as a result, the early bolting rate of the seedlings cultivated with the seeds of flowering and fruiting in the second year was 30% higher than that of the seeds in the third year, and the bolting time was 10% and 15 days earlier. At the same time, the seed bolting rate of Angelica sinensis is also related to the seed maturity, the fully mature seeds have strong vitality, the growth is exuberant after planting, the bolting rate is high, and the vitality of tender seeds is weak. Although it will not bolt early after sowing, it has low survival rate, weak growth and low yield. it is also difficult to adopt in production. Therefore, in order to improve the seedling quality and reduce the early bolting rate, the seedlings must be planted in the current three-year-old field with large roots, strong growth, late flowering, moderate seed maturity (fish belly white) and uniform seeds. Due to the inconsistent development of the main stem and lateral branches of Angelica sinensis, the main stem must be cut off at the early stage of bolting, so as to promote the uniform development of each branch in order to obtain seeds that meet the requirements of production. 2. Sowing at the right time, fertilizing reasonably, controlling seedling age and seedling weight. According to the production practice: Angelica seedlings not only need a certain low temperature, but also need enough sugar, so the tall seedlings are easy to bolting and flowering, but the early bolting rate of seedlings is very low. At the same time, the seedling age also had a great effect on bolting, and the early bolting rate of older seedlings was higher when the same batch of seeds were raised at the same time and the root weight was the same. According to the data of Taibai County, Shaanxi Province, using seeds harvested in three years to raise seedlings, the seedling age is more than 130 days, the early bolting rate is more than 90%, and there is almost no early bolting phenomenon when the seedling age is less than 70 days. But the seedling age is too small, the seedling root weight is small, the survival rate is low, the growth is weak, the yield is low and the benefit is poor. In order to control large seedlings and old seedlings and reduce the rate of early bolting and flowering, the sowing date should be postponed appropriately, the seedling age should be controlled within 110 days, the weight of 100 seedlings should be less than 40 grams, and nitrogen fertilizer should be applied properly in the later stage of seedling raising to increase the total nitrogen content of plants so as to reduce the total sugar content of plants. inhibit bolting and flowering. 3. Lower the storage temperature of seedlings and lower the storage temperature below 0 ℃. Because the suitable temperature required for vernalization is 0 ℃ 5 ℃, the seedlings will be stored in a dormant state when the seedlings are frozen below 0 mol. If they cannot pass the vernalization stage, the early bolting rate can be reduced to zero. 4. Change the cultivation mode, postpone the sowing time, change the seedling transplanting to autumn direct seeding, and control the early bolting. In addition, planting density, climatic conditions, altitude, soil fertility and other conditions have a certain impact on the early bolting of Angelica sinensis. Drought, thin land, sufficient light, low altitude and low sowing density are not conducive to the vegetative growth of Angelica sinensis. The early bolting rate is high. According to the growth characteristics of Angelica sinensis, the growers should manage strictly according to the cultivation requirements, reduce the early bolting rate and improve the yield and quality of Angelica sinensis. Click to get more Angelica planting technology click to get more medicinal material planting technology