What causes early bolting in Angelica sinensis? How to prevent and control it
During the cultivation of Angelica sinensis, early bolting often occurs. Angelica sinensis that bolts and flowers early is highly woody, lacks oiliness, and cannot be used medicinally, causing huge economic losses to farmers. So what causes early bolting in Angelica sinensis? How should it be prevented? Let's take a look at the detailed introduction below.
I. Causes of bolting
1. Genetic factors: When planting with seed from bolted Angelica sinensis, the bolting rate of seedlings grown from seed kept from normal seed plants, over-mature seed, or old seed is relatively high, at around 80-90%.
2. Ecological factors: When planted on sunny slopes with lower altitude and high temperatures, drought easily causes early bolting. In addition, seedlings stored in shaded areas have a bolting rate about half lower than seedlings stored in sunny areas. When shading after transplanting reaches about 50%, the bolting rate drops by 60%. When the day length reaches more than 14 hours, its bolting rate reaches its 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, with the bolting rate clearly increasing. 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. Excessive sowing density can also lead to early bolting. Transplanting too early also very easily causes bolting, while later transplanting lowers the bolting rate. When too much flower fertilizer is applied, the bolting rate of the plants clearly increases, 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 clearly increases the bolting rate of Angelica sinensis. When Angelica sinensis is in the vegetative growth stage and in a high-temperature, dry climate, its bolting rate also clearly rises.
II. Control methods
When planting, select good seed and choose seed that is not prone to bolting. At the same time, sow at the proper time, control large seedlings and old seedlings, and reduce the rate of early bolting and flowering. The sowing time should be delayed, the seedling age should be controlled within 110 days, and the seedling weight should be below 40 grams. In the later seedling stage, appropriately increase nitrogen fertilizer application to raise the nitrogen content of the plants, reduce the sugar content of the plants, and inhibit bolting and flowering. In addition, density should be controlled when sowing. Generally, 3-5 kg of seed per mu is sufficient. Do not use too much, so as to avoid excessively high density, which makes bolting very likely.
The above is an introduction to the causes of early bolting in Angelica sinensis and the control methods. We hope it can help you. To learn more related knowledge, please stay tuned to us.