What to Do About Early Bolting in Angelica sinensis? Causes and Control Methods
During the cultivation of Angelica sinensis, early bolting often occurs. Angelica sinensis that flowers and bolts prematurely has high woodiness, lacks medicinal value, and cannot be used as medicine, causing huge economic losses for farmers. So what causes early bolting in Angelica sinensis? How can it be prevented? Let's take a look at the detailed introduction below.
I. Causes of Bolting
1. Genetic factors: When planting with seeds from bolted Angelica sinensis, seeds retained from normal seed plants, over-mature seeds, or old seeds, the seedlings cultivated have a relatively high bolting rate, around 80-90%.
2. Ecological factors: When planted on sunny slopes at lower altitude and high temperature, drought easily causes early bolting. In addition, seedlings stored in shady places have a bolting rate about half lower than seedlings stored in sunny places. When shaded at about 50% after transplanting, the bolting rate decreases by 60%. When the sunshine duration reaches more than 14 hours, its bolting rate reaches a peak.
3. Nutritional factors: Early bolting in Angelica sinensis is also closely related to the size and quality of its seedlings. At the same seedling age, the heavier the seedling, the faster its bolting process and the earlier the bolting time, and the bolting rate increases significantly. In addition, early bolting also has a certain relationship with the nitrogen content and sugar content of the seedlings.
4. Improper cultivation: The earlier the sowing time, the higher the early bolting rate. Too high sowing density can also cause early bolting. Transplanting too early also easily causes bolting, while later transplanting reduces the bolting rate. When too much flower fertilizer is applied, the bolting rate of the plants increases significantly, among which diammonium phosphate is the highest. Phosphate fertilizer has an obvious effect on the bolting rate of Angelica sinensis. Applying nitrogen and phosphorus fertilizer accelerates bolting, and applying too much nitrogen and potassium fertilizer significantly increases the bolting rate of Angelica sinensis. During the vegetative growth period, under high temperature and drought climate, its bolting rate also increases significantly.
II. Control Methods
When planting, select good seeds, choose seeds that are not prone to bolting for planting, and sow at the right time, control large seedlings and old seedlings, and reduce the early bolting and flowering rate. The sowing time should be delayed, and the seedling age should be controlled within 110 days, with seedling weight below 40 grams. In the later stage of seedling growth, appropriately increase nitrogen fertilizer application to raise the nitrogen content of the plants and lower the sugar content of the plants, thereby inhibiting bolting and flowering. In addition, when sowing, control the density. Generally, 3-5 kg of seeds per mu is sufficient. It should not be too much, so as to avoid excessively high density, which makes bolting very likely.
The above is an introduction to the causes and control methods of early bolting in Angelica sinensis. We hope it can help you. If you want to learn more related knowledge, please stay tuned to us.