How to Prevent and Control Celery Bolting? A Full Analysis of Practical Measures
Celery belongs to the Apiaceae family. There are two types: water celery and dry celery (upland celery); their functions are similar, but dry celery is better for medicinal use. Dry celery has a stronger aroma and is also known as “fragrant celery.” The fruit (or seed) of celery is small and has a fragrance similar to that of the plant; it can be used as a seasoning, especially for soups and pickles. Celery seed contains about 2 to 3% essential oil, whose main components are d-limonene (C10H16, i.e. limonene) and selinene (C15H24). Celeriac (A.g. var. rapaceum) has an edible thick root and can be eaten raw or cooked as a vegetable.
According to modern scientific analysis, every 100 grams of celery contains 2.2 grams of protein, 0.3 grams of fat, 1.9 grams of carbohydrates, 160 milligrams of calcium, 61 milligrams of phosphorus, 8.5 milligrams of iron, and also contains carotene and various other B vitamins. Celery is rich in nutrients and contains relatively high amounts of calcium, phosphorus, iron and provitamin A, vitamin C, vitamin P, etc.; it has long been used both as food and as medicine. Celery is sweet and cool in nature and flavor, and has the effects of clearing the stomach and eliminating phlegm, dispelling wind and regulating qi, benefiting the mouth and teeth and refreshing the throat, clearing the eyes and improving vision, and lowering blood pressure. In addition, celery contains abundant volatile aromatic compounds, which can not only increase appetite and promote blood circulation, but also have a dietary therapeutic effect of refreshing the mind and invigorating the spirits.
Traditional Chinese medicine holds that celery is sweet and cool in nature and has the effects of clearing heat, promoting urination, lowering blood pressure, and reducing fat. For medicinal use, it can be decocted in water and taken orally or pounded into juice for external application, and can serve as an auxiliary treatment for early-stage hypertension, hyperlipidemia, bronchitis, tuberculosis cough, headache, insomnia, excessive menstruation, functional uterine bleeding, difficult urination, accumulated heat in the lungs and stomach, measles in children, mumps, and other conditions.
Preventive and control measures for celery bolting
1) Scientific cultivation management
In celery cultivation, increasing the temperature of the celery seedling bed and avoiding the low temperatures that lead to vernalization is one of the effective measures for reducing premature bolting in celery. Celery seedling raising now takes place in the cold winter. If the daytime temperature in the cold frame is kept at 15 degrees Celsius to 20 degrees Celsius and the nighttime temperature is kept at 8 degrees Celsius to 10 degrees Celsius, vernalization can be avoided. To achieve this goal, the following measures are usually taken: sow appropriately late. Raise seedlings late to avoid the severe cold season, and raise seedlings when the temperature warms up, thereby ensuring a relatively high temperature in the seedling bed. Before sowing, the seedbed can also be thoroughly “heated” to raise the temperature inside the sowing bed. Build windbreaks and add heat-preserving covers to improve wind protection and insulation performance. Frequently clean and wipe the plastic film so that it has relatively high light transmittance. During the seedling stage, water less and water lightly to avoid lowering the soil temperature. After spring celery has grown, most plants already have flower stalks; the earlier the harvest, the shorter the flower stalks, and the later the harvest, the longer the flower stalks. Therefore, harvest at the right time to avoid overly long flower stalks reducing celery quality. Using the method of harvesting by splitting off leaves can also prevent early bolting.
1. Select solid-stem varieties with strong winter hardiness that are not prone to premature bolting.
2. Use new, plump seeds. Such seeds have strong growth vigor and vigorous growth, with lighter premature bolting. When collecting seeds, strictly follow agronomic operation technical requirements, and strictly prevent the use of prematurely bolted plants for seed production; otherwise, the winter hardiness of the variety will be greatly reduced, causing quality degeneration and intensifying the occurrence of premature bolting.
3. When raising seedlings in the low-temperature seasons of winter and spring, take all effective measures to avoid low temperatures below 8°C to 10°C. The nighttime temperature should be above 8°C to 12°C, and the daytime temperature should be 15°C to 20°C, to prevent seedlings from passing through vernalization.
4. During the growth period, increase water and fertilizer management to ensure normal growth and development, promote vigorous vegetative growth, and inhibit reproductive growth. Prevent environmental conditions such as drought, insufficient fertilizer, and seedling hardening.
5. On the premise of strengthened management, spray growth hormones in a timely manner. During the peak growth period, spray once every 7 to 10 days, for 2 to 3 consecutive sprays of 20 to 50 mg/L gibberellin, which can promote vegetative growth and inhibit bolting and flowering.
6. Harvest appropriately early; do not wait until bolted plants are old before harvesting.
2) Skillful use of gibberellin
Gibberellin can promote vegetative growth, increase yield, improve quality, and slow premature bolting in celery. The commonly used concentration is 20 to 50 PPm. Gibberellin must not be mixed with alkaline pesticides, and its application concentration must not be increased arbitrarily; otherwise, celery will die or grow abnormally. The application time should be during the peak growth period of celery, spraying once every 7 to 10 days, for 2 to 3 consecutive sprays, and stopping spraying 15 days before harvest. Proper spraying can increase celery yield by more than 20 percent, and its leaf stalks will become longer, crisp, and tender.