Full analysis of celery seedling-raising techniques: easily grow strong, healthy seedlings
Key points of celery seedling-raising techniques. Celery can be cultivated all year round, and its seedling-raising time and methods vary with the cultivation time and method. 1. Seedling raising for spring cultivation (1) Seed treatment. 5 to 6 days before sowing, sun the seeds for 1 to 2 days. When sunning the seeds, do not spread them directly on a concrete surface. Soak the seeds for 24 hours, and change the water 1 to 2 times during soaking...
Key points of celery seedling-raising techniques
Celery can be cultivated all year round, and its seedling-raising time and methods vary with the cultivation time and method.
1. Seedling raising for spring cultivation
(1) Seed treatment. 5 to 6 days before sowing, sun the seeds for 1 to 2 days. When sunning the seeds, do not spread them directly on a concrete surface. Soak the seeds for 24 hours, and change the water 1 to 2 times during soaking.
(2) Sowing. For open-field seedling raising, the sowing time is from late October to the end of November, with mulch coverage for freeze protection during the overwintering period, or raise seedlings in a greenhouse in early to mid-February. The sowing rate is 10 grams per square meter of seedbed, and the seed rate is 7500 grams per hectare. At sowing, every 1 kilogram of seeds can be mixed evenly with 5 kilograms of fine soil before broadcasting. After sowing, cover with a 0.3 cm layer of fine soil and a shade net.
(3) Seedbed management. Before emergence, mainly maintain the moisture of the seedbed, and remove the shade net when the seedlings push through the soil. After emergence, the seedbed should maintain a certain humidity, but should not be watered too much. 2 to 3 days after emergence, begin thinning the seedlings, and thin again at the 2-leaf stage. When the seedlings grow to 3 to 4 leaves, appropriately control watering for hardening off to promote root development. When the temperature drops below 0°C, cover with a shade net or straw curtain, etc. For seedling raising and cultivation in a greenhouse, more fertilizer can be applied in the later stage of seedling raising to promote growth. If the night temperature in the greenhouse is too low, attention should be paid to keeping it warm.
2. Seedling raising for summer cultivation
The sowing period is from late March to late May. The sowing rate is 7 grams per square meter of seedbed. Sow after soaking the seeds for 24 hours. Cover with soil 0.8 to 1 cm deep. After emergence, thin the seedlings in time, with a seedling spacing of about 2 cm. For sowing in late April, no longer cover with plastic film. After sowing and before emergence, cover with a shade net to help retain moisture. The seedbed specifications and requirements are the same as for spring cultivation seedling raising.
3. Seedling raising for autumn cultivation
The sowing period is from early June to mid-July for seedling raising, and planting out from late July to late August. Because the sowing period for autumn cultivation falls in the high-temperature summer season, and the suitable temperature for celery germination is 15 to 25°C, with emergence being difficult above 30°C, seed treatment must be carried out.
(1) Alternating temperature treatment. After soaking, wash the seeds clean, wrap them in gauze, squeeze out part of the water, place them in a refrigerator, and keep them at about 5°C for 2 days, rinsing with clean water twice each morning and evening. Then spread the seeds out to air in a lighted environment at 15 to 22°C, still rinsing the seeds with cool water twice a day, after which an electric fan can be used to blow on them for 5 to 10 minutes to blow away excess water attached to the seeds, preventing too much water from causing insufficient oxygen and affecting germination. Generally, after 4 to 5 days of treatment, they will germinate.
(2) Hormone treatment. After soaking the seeds for 12 hours in 5 mg/L gibberellin (920), rinse them clean with clean water, then soak them in clean water for 8 hours, and then spread them out to air in a lighted environment at 15 to 22°C according to the above method.
(3) Cool treatment. Wrap the seeds already soaked according to the first method in gauze and squeeze them dry, then hang them in a deep well 40 to 50 cm above the water surface, also rinsing twice a day by the same method as above. After 5 to 6 days, they will germinate.
After sowing, cover with a 0.8 cm thick layer of fine soil, lay 1 to 2 layers of shade net flat on top, then spray enough water, and afterward keep the soil moist. After emergence, promptly remove the shade net laid flat on the ground. Thin the seedlings once when the true leaves appear, and thin again at the 2-leaf stage, with a seedling spacing of 4 cm × 2 cm, and plant out at 4 to 6 leaves.
4. Seedling raising for winter cultivation
Sow from late August to early September, which can be done in a greenhouse, and in high temperatures a shade net is still needed for coverage. Because the seeds used for winter cultivation are mostly new seeds harvested that year, they are still in dormancy at sowing time, and the method for breaking dormancy is the same as for autumn cultivation. The sowing method can refer to autumn cultivation seedling raising. For seedbed management, if the temperature has already dropped, proceed according to the spring seedling-raising method.