Celery is rich in carotene, vitamin B2 and volatile aromatic oil, which is one of the main vegetables that the masses love. Celery is grown in the summer, usually in mid-June, transplanted in late July, and launched in late September. Because celery is a cold-tolerant vegetable, it is required to be cold and moist, avoid hot, and the optimum temperature is 15-20 °C. Therefore, seedlings in the high temperature period must be covered with shading nets, low temperature germination and other related measures to achieve the purpose of improving local microclimate, create environmental conditions suitable for celery growth, achieve high yield and quality, and enrich the summer and autumn "vegetable blue" market. The main breeding techniques are now introduced as follows. 1, variety selection Summer celery should be selected from heat-resistant, early-maturing and disease-resistant varieties, such as green celery celery, Jinnan Shiqin No. 1, glass crisp celery and so on. These varieties have fewer petiole fibers, grow faster, are less prone to aging, and have good quality. 2, sowing seedlings (1) Selection of seedlings and preparation of seedbeds In the summer stage of celery, due to the high temperature, the weak resistance of the seedlings is poor. As far as possible, choose a terrain with high dryness, convenient watering and drainage, good ventilation, fertile soil and a film-covered greenhouse. Before planting, it is necessary to apply enough base fertilizer, deep and flattened, high-pitched, narrow-necked, and wide 1.2-1.5 m wide. Pour enough water 1 to 2 days before sowing, and wait until it is slightly dry before planting the topsoil. (2) Soaking seeds and germination Because the celery seeds are small, the seed coat is thick. Before germination, the seeds are placed in a water temperature of 50-55 ° C for soaking and disinfecting, stirring constantly, so that the seeds are evenly heated and fully absorb water (killing the surface of the seeds) ). After 20 minutes, take it out and put it in cold water to continue soaking. After 16 to 24 hours, gently rub it 2 to 3 times by hand to remove the empty shell floating on the water surface. Rinse the granules with water, remove the seeds, and drain the water. When the surface of the seed is dry and wet, use gauze to wrap it in a cool place to germination, or put it in the refrigerator freezer (about 5 °C), or hang it in the well 30 to 40 cm above the water surface to promote germination. The temperature is 20 to 22 °C. Check and rinse the seeds several times a day to keep the seeds moist. After 7 to 12 days, the seeds begin to germinate, and more than 50% of the seeds can be sown after germination. (3) Fine hoeing before sowing sowing, so that the middle of the glutinous surface is slightly higher, and the sides are slightly lower. The kneading surface should be flat, not concave and convex, in order to prevent the rainy weather from being covered with water; in the nursery, spray 48% of the espresso emulsifiable concentrate 600 times to prevent the harm of underground pests to the seedlings. Before sowing, the seedbed should be fully watered to reduce the soil temperature. After the soil absorbs water, the topsoil is slightly dry and not sticky. When the temperature is low in the evening, the soil is sown. After sowing, cover a layer of 0.5 to 1.0 cm mixed with the seedlings. Disease. 3. Seedling management (1) Covering the shading net For the summer celery, the shading net is the most ideal for the silver-gray effect. The sowing time of the summer celery is generally in the middle and late June, and it is covered with a small arch shed or a flat shed before planting until the planting. The coverage time is from sowing until mid-July, after which the net is removed to facilitate its normal growth. On sunny days, the method of early cover and late release is adopted, that is, around 9:00 in the morning, when the morning dew is not dry, the net is covered to maintain a fresh, humid, cool and suitable microclimate, and promote its growth. At about 16 o'clock in the morning, the net is ventilated to reduce the temperature. At the same time, you can get the night dew to moisturize. Cloudy and light rain weather can be covered, and the net must be covered before the rainstorm. (2) Reasonable watering During the seedling period, special attention should be paid to the mastery of water: generally, the principle of small water is poured and the soil is moist. On a sunny day, increase the number of waterings per day and reduce the amount of watering each time. Watering 1 to 2 times a day before sowing, choose morning or evening. After the emergence of the seedlings, pour 1 or 2 times a day, wait until the 2 leaves, 3 to 4 days after watering 1 or 2 times, after 4 to 5 pieces of true leaves, reduce the number of watering, keep the soil dry and see wet. Due to the slow growth of the seedling stage, the weather is hot, the soil is moist, the weeds are easy to breed, the intercropping is combined, the weeds are removed, and each time the seedlings are watered once, the water is gently poured once, and the thin layer of soil is covered after the seedlings. (3) Timely fertilization of seedlings in the early stage is generally not topdressing, and found that the growth is weak, after the seedlings can be applied to the foliar fertilizer, such as 0.3% potassium dihydrogen phosphate and 0.2% urea mixed fertilizer to promote the growth of seedlings. Gradually shorten the shading time during the day until all the shading equipment is removed, so that the seedlings can be exercised and the adaptability to high temperature is enhanced. (4) Spray control After planting (pre-emergence), chemical herbicides can be used. Generally, 50% of the grassy wettable herbicides are used in an amount of 100-150 grams per acre, 60-70 kilograms of water, evenly sprayed, and weeded. The effect is better. After the seedlings, in order to prevent the occurrence of squatting, the solution of 800% thiophanate-methyl WP can be sprayed 800-1000 times every 7 days for 3 times, which can effectively prevent dead seedlings and burning seedlings. Auto Hematology Analyzer,Clinical Hematology Analyzer,Blood Analyzer Hematology,Hematology Analyzer Guangdong Widinlsa International Co.Ltd , https://www.gdwidinlsa.com
The main points of nursery techniques of summer celery