China News Service, March 2. According to the website of the Ministry of Agriculture and Rural Affairs, the recent outbreak of the new coronavirus has caused certain impacts on vegetable seedlings, transplanting, field management and market supply. In order to strengthen the management of spring vegetable seedlings, to ensure the smooth development of vegetable seedlings and transplanting during the epidemic period, and to ensure the stability of vegetables in late spring and early summer, the National Agricultural Technology Extension Service Center organized experts to develop intensive vegetable seedlings for 2020 Technical Opinions on Intensive Seedling Production (hereinafter referred to as "Opinions").
Data map: Farmers loosen soil in the field. Photo by Qu Honglun of China News Agency
The "Opinions" point out that we must strengthen the defense against severe weather. At present, sunlight greenhouses are the main facilities for vegetable seedling cultivation in the Northeast, North China, and Huanghuaihai areas. Plastic greenhouses or small and medium-sized arch sheds are the main facilities for vegetable seedling cultivation in the Yangtze River Basin and the southern and southwestern regions. At present, the types of vegetables that need to be transplanted include cucumber, tomato, eggplant, pepper, zucchini, watermelon, and melon. With the rise of temperature and the extension of light hours, the weather conditions will be conducive to the growth of seedlings as a whole, but the temperature is unstable in early spring, it will occur in the cold spring, cloudy days and haze days, which may cause seedling chilling damage, flower bud differentiation or seedling lengthening Such as adverse effects, reducing seedling quality and early production after planting, it is necessary to strengthen the monitoring of severe weather and make good technical plans for disaster prevention and mitigation.
The "Opinions" mentioned that it is necessary to strengthen the early warning and regulation of the nursery environment. Strengthen the maintenance and management of nursery facilities, and improve the tightness and thermal insulation of solar greenhouses and greenhouses. Under the premise of ensuring the temperature during the day, the northern solar greenhouse should cover the insulation quilt as soon as possible as soon as possible. After the temperature rises, open the indoor insulation film in time. In rainy and rainy days, the insulation quilt should also be removed in a timely manner. When the temperature in the southern plastic greenhouse is high at noon, ventilation should also be carried out to reduce the humidity in the greenhouse. In continuous cloudy and haze weather, if there is supplementary light condition, artificial supplementary light should be performed in time. Keep warm at night, cover the insulation quilt and inner insulation film, and ensure that the temperature of the seedlings of melons and vegetables is not lower than 15 ℃, and the temperature of eggplants is not lower than 12 ℃. Turn on the auxiliary heating device.
The "Opinions" said that it is necessary to strengthen the precise management of water and fertilizer in the seedling stage. Differential water and fertilizer management is implemented according to the seedling growth and development process. As far as possible, choose sunny morning and use the irrigation water stored in the greenhouse in advance. Normally growing seedlings are applied with balanced water-soluble fertilizers every 5 days at a concentration of 100-200 mg / L, and long-length seedlings are high-potassium, calcium-magnesium-containing water-soluble fertilizers. Weakly growing seedlings appropriately increase nitrogen content. In rainy days, try not to water to reduce the humidity in the shed. When the humidity is high, turn on the axial fan to increase the air disturbance in the shed to prevent the leaves from getting wet or dew. The conditional nursery can also use air dehumidifier to reduce the humidity in the shed.
The "Opinions" stated that the prevention and control of plant diseases and insect pests during the seedling stage should be strengthened. Clean the surroundings of nursery facilities. Bare land is covered with horticultural cloth to keep the room clean and hygienic. Waste substrates, plant residues and standing water are removed daily. The nursery floor is sprayed with 500 times potassium permanganate disinfectant once a week. Sprinkle lime powder at the corners. The facilities and seedbeds before nursery are disinfected by potassium permanganate and formalin smoke method, and the trays are disinfected by 40% formalin before reuse. The seeds are recommended to be disinfected by hot water or hypochlorous acid. The air outlet of the facility is equipped with insect-proof nets of more than 60 mesh, and yellow and blue sticky insect boards are hung on the seedbed. As the temperature rises, the humidity in the shed should be appropriately reduced to prevent seedling disease and bacterial wilt. Attention should be paid to the prevention and control of aphids, whitefly, and thrips. Observe new leaves. Once the diseases and insect pests are found, use the medicine as soon as possible.
The "Opinions" emphasized that the classification and regulation of seedlings should be strengthened. One week before the seedlings come out of the nursery, measures such as cooling, ventilation, water control, and lightening are used to refine the seedlings. Cooling should be carried out gradually, water control should be appropriate, and ventilation should be from small to large. During the day of seedling cultivation, the temperature during the day can reach 15-20 ° C, and the night temperature can be reduced to about 12 ° C for a short time. The relative humidity of the substrate can be gradually reduced to 40% -50%, and the relative humidity of the air can be reduced to 30% -40%. During seedling cultivation, try to make the seedlings more ventilated and more visible. If excessive growth occurs, you can reduce the use of nitrogen fertilizer, especially ammonium nitrogen, increase the use of potassium and calcium fertilizers appropriately, adopt the method of thinning disks, pull a certain distance between the trays to improve ventilation, and expand the nutrient area to avoid leaf obstruction. .
The "Opinions" finally pointed out that the prevention and control of epidemic situation in nursery farms should be strengthened. Vegetable seedling farms are relatively labor-intensive, and the internal operations of the seedling farms are highly mobile, such as the operation of machinery, production management, and the transportation of commercial seedlings. Do a good job of scientific protection and safe production of seedling farm epidemics, ensure the safe operating environment of seedling farm workers, ensure timely and stable supply of seedlings in main production areas, and focus on the following ten items: first, follow the order and arrange in an orderly manner; Isolate; Third, disinfect the environment and ventilate in a timely manner; Fourth, wear a mask and change it regularly; Fifth, measure the temperature to get on the job and change into the field; Sixth, keep a distance and work safely; Seventh, waste products and centralized treatment; Peak shift meals; Nine to raise awareness and scientific precautions; Ten to find suspects and report as soon as possible.