Celery field management technology in February

Celery is a vegetable crop with very high edible value. It is rich in nutrients. Eating celery regularly can clear away heat and detoxify, cleanse the intestines and strengthen the stomach, moisten the lungs and relieve coughs. It is not difficult to grow. Let’s talk about the field management techniques of celery in February.

1. Suitable temperature management promotes germination

Celery has a hard seed coat, small seeds, poor water permeability, slow germination and difficulty in germinating. Under suitable conditions, seedlings generally begin to emerge a week after sowing. In early spring, the temperature is low and delayed germination is prone to occur. The suitable temperature for celery germination is 15-20°C. Above 25°C or below 15°C, the germination rate decreases and the germination time is prolonged. The lowest germination temperature is 4°C. Therefore, in order to ensure uniform seedlings, good temperature management is required. The nursery can adopt methods such as adding a small arch shed to the seedbed, heating the seedling shed, laying electric heating wires, etc. to maintain the greenhouse temperature as much as possible. The nursery with a germination room can carry out centralized germination for 5 to 7 days. Variable temperature treatment can promote germination. The daytime temperature is controlled at 22-25°C and the night temperature is reduced to 15-18°C.

2. Timely seedling transplanting to promote growth

Celery seeds are small, with a germination rate of about 80%. It is difficult to sow one seed per hole using bare seeds. Generally, a 128- or 105-hole hole tray is used, with 3 to 4 seeds per hole, or a flat tray direct seeding method is used. Therefore, seedling adjustment and separation are required in a timely manner to promote later growth, thereby ensuring that the seedlings in the same hole tray are of uniform size for unified management. The time for transplanting seedlings is generally about 40 days after sowing, when the seedlings are at the 2-leaf stage. When transplanting seedlings, gently remove the substrate lump in the seedling tray, break the substrate lump with your hands, sort the seedlings by size, move seedlings of the same size into the same hole tray, take out the seedlings one by one with a fork or tweezers, and move them into the seedling tray filled with substrate, remove weak and small seedlings, and water them thoroughly in time after transplanting.

3. Cutting technology promotes root growth

For celery seedlings that have not been divided, have underdeveloped root systems, and are growing weakly, the pruning method can be used to promote root development. When the seedlings are 5 to 6 cm tall, use scissors to cut off the upper leaves, leaving only the heart about 1 cm above the substrate to continue growing. This can be done 1 to 2 times during the entire seedling period. It should be noted that pruning will prolong the growth time of seedlings, so it is necessary to sow in advance and make plans according to the planting time.

4. Precise environmental control to prevent diseases

After celery seedlings emerge, temperature and humidity management must be strengthened to avoid diseases such as damping-off and sudden wilting. After the seedlings have all grown, the daytime temperature should be between 15 and 20 degrees Celsius, not exceeding 25 degrees Celsius, and the nighttime temperature should not be lower than 8 degrees Celsius to prevent the seedlings from growing too tall due to excessive temperature. When the temperature is high in the morning on a sunny day, lower the temperature and humidity in the greenhouse and open the upwind vents in time for ventilation. If it is cloudy and the temperature is low, to promote growth, take measures to increase temperature and supplement light, appropriately shorten the time of opening vents, and reduce watering.

5. Reasonable water and fertilizer to prevent excessive growth

Celery seedlings are relatively old and grow slowly, usually 70 to 80 days old in the winter and spring, and have 4 to 6 leaves at the physiological age. The principle of irrigation in the seedling stage is generally to water frequently with small amounts of water to avoid excessive watering and to keep the substrate "dry and wet" to prevent root rot. Reasonable topdressing can basically supply nutrients for growth in the substrate during the germination period. After all the seedlings have emerged, depending on the growth of the seedlings, the cotyledons flatten to the 2-leaf stage. It is recommended to use 0.1% concentration of ternary compound fertilizer water-soluble fertilizer (NPK is 19-19-19). Increase the fertilizer concentration by 0.3% from the 2-leaf stage to seedling formation. Prevent the formation of leggy seedlings with thin leaves and long petioles when the temperature is too high or there is too much nitrogen fertilizer.

6. Heat preservation in the later stage to prevent bolting

Celery is a green vernalization vegetable. It can sense low temperatures after the seedlings have 3 to 4 leaves, and is most sensitive when they have 5 to 6 leaves. If the celery seedlings experience low temperatures below 10°C for 10 to 15 days or longer, they will pass the vernalization stage. When the celery encounters high temperature conditions or long periods of sunshine again, they will bolt and bloom prematurely, affecting the commercial value of the celery. The longer the seedlings are in low temperatures, the higher the bolting rate. Therefore, measures should be taken in two periods. First, in the later stage of seedling raising, long-term low temperature should be avoided. Second, after transplanting, seedlings should not be allowed to stand, and sufficient fertilizer and water should be supplied to promote the nutritional growth of celery, and the bed surface should be kept moist. As the temperature rises, gradually increase the number of waterings, water once every 4 to 5 days in the early stage, and once every 2 to 3 days in the later stage, to keep the soil moist.

That’s it