Management Techniques After Transplanting Greenhouse Celery
Greenhouse celery has a relatively long seedling stage, generally requiring 2 to 3 months. It can be transplanted when the seedlings grow to 10 cm tall with 7 to 8 true leaves.
Before transplanting, apply 6000 kg of high-quality organic fertilizer and 50 kg of diammonium phosphate per mu in the protected area, dig deep and rake fine, make flat beds 1.3 m wide, with a transplanting row spacing of 25 cm and plant spacing of 20 cm. Water the seedling bed thoroughly one day before transplanting. It is best to transplant on a cloudy day or in the evening, select strong single seedlings with soil balls, water while transplanting, promptly put up the greenhouse film, pay attention to ventilation in the greenhouse, and strictly prevent the seedlings from being scorched.
After transplanting, if there is sudden clear hot weather, shade promptly at noon for 2 to 3 days. After transplanting, preserve soil moisture to help the seedlings recover, and water 2 to 3 times. After the seedlings recover, cultivate deeply and appropriately restrain growth. When the minimum temperature drops to 5°C, pay attention to keeping warm at night, and ventilate during the day to lower temperature and humidity, preventing the plants from excessive vegetative growth and disease. Keep the daytime temperature at 20°C to 25°C and the nighttime temperature at about 10°C. In mid-November, straw curtains should be added for insulation, and ventilation should be carried out for more than 2 hours every day. On cloudy days, also pay attention to ventilation to reduce humidity, and shorten the ventilation time. When the plants grow to 25 to 30 cm tall, apply fertilizer once, with 20 kg of urea per mu, and water immediately afterward. After that, the plants enter a period of vigorous growth and must not lack water. Water about every 7 to 10 days, and topdress fertilizer once between waterings. Watering is generally done in the morning on sunny days. At the same time, seal the greenhouse tightly and raise the temperature, which can make the soil temperature rise quickly, and ventilate at noon to remove humidity. During the vigorous growth period of celery, lack of water, nitrogen deficiency, or low temperature can easily lead to hollow petioles, boron deficiency can easily cause stem cracking, and calcium deficiency may cause black heart disease, etc. Therefore, water and topdress fertilizer in a timely manner, keep warm, and apply more organic fertilizer to ensure the supply of trace elements. In the middle and late stages of growth, spray potassium dihydrogen phosphate or urea solution on the leaves. Pay attention to preventing and controlling pests and diseases. For leaf spot and late blight, spray with 75% chlorothalonil wettable powder at 600 times dilution; on cloudy days, use chlorothalonil smoke agent for fumigation. For gray mold, spray with carbendazim or mancozeb at 800 times dilution. For aphids, spray with pirimicarb at 1000 times dilution.
When the plants grow to the standard height, they can be harvested, generally from late December to early February of the following year. The growing period must not be too long, as hollowing will occur and quality will decline if it is too long.
Vegetable Bureau of Xiajin County, Shandong Province Wang Deming Yang Defeng