Pollution-free cultivation of tomato in open field
1. Prepare before sowing. According to the different seasons and climatic conditions, we must use sunlight greenhouses, plastic sheds, warming greenhouses, Yangshuo, and seedbeds, and nursery facilities. In addition, summer and autumn nurseries should also be equipped with pest control and sunshade facilities. Conditional use can be made of plug seedlings and plants. Raising seedlings and disinfecting nursery facilities. To prevent or reduce the occurrence of pests and diseases at seedling stage, to create environmental conditions suitable for the growth and development of seedlings. In addition, we must also prepare nutritious soil. In general, it is necessary to select a pest-free gardenland soil, decomposed farmyard fertilizer, peat moss, vermiculite, alfalfa ash and compound fertilizer according to local conditions. Prepare a nutrient soil in a certain proportion and require that the porosity of the nutrient soil be about 60%, ph6-7, including Available phosphorus 100 mg / kg or more, available potassium 100 mg / kg or more, available nitrogen 150 mg / kg, loose, fertilizer, water, complete nutrition. Spread the prepared nutritious soil evenly on the seeding bed (thickness 10 cm), or on the seedling tray. Sowing amount is determined. The average tomato seed contains about 300 grains per gram. According to the density of planting, it is generally 20-30 grams per 667 square meters. Seed bed can be sown 10-15 grams per square meter. If the seed germination rate is less than 85%, the sowing rate should also be increased appropriately. Tomato seed disinfection. There are two methods: (1) soaking in warm soup, soaking seeds with fresh water for 1-2 hours, then removing the seeds into hot water at 55 degrees Celsius, maintaining the water temperature evenly for 15 minutes, and then soaking for 3-4 hours. When soaked in warm soup, it is generally a seed and two parts of water; it must be continuously and rapidly stirred to evenly heat the seeds so as not to scald the seeds; the third is to continuously heat the water and maintain the water temperature of 55 degrees Celsius. It can prevent diseases such as leaf mold, canker disease and early blight. (2) Soaking with trisodium phosphate, ie soaking with fresh water for 3-4 hours, removing and draining, then soaking in 10% trisodium phosphate solution for 20 minutes, remove and wash. This method has a clear effect on tomato virus disease. Seeds can be sown directly after treatment, but germination is preferred. When germination is performed, the seeds, which are usually not treated with chemicals, need to be soaked in warm water for 6-8 hours to fully inflate the seeds and then left to bud for 2-3 days at a temperature of 25-28 degrees Celsius. The seed soaked with the agent can be directly germinated by simply flushing the seed with water. During the germination process, suitable temperatures, moisture, and air must be provided. To this end, the seeds must be inspected and turned over frequently to loosen the seeds. The seeds must be rinsed once or twice a day to refresh the air and maintain the humidity. Germination is best used incubators. After the germination of the seeds, seedlings emerge quickly and neatly, which is conducive to the cultivation of robust seedlings. Before sowing tomatoes, enough seeding beds should be prepared according to the planting plan. In order to prevent the bacteria from harming, the nursery bed should be disinfected before sowing. In most regions of China, especially in the northern regions, the bottom water must be fed in the seeding bed before sowing, and the amount of water in the bed soil 8-10 cm deep should be saturated. General points seedlings are no longer watered before transplanting. In areas with high water level in the south or in the groundwater level, only a small ditch should be opened on the surface of the bed before planting. Use pots to pour in small water until the water seeps and then sow. Afterwards, use watering can to spray water in order to prevent soil compaction. . After the bottom of the water seepage, thin layers of fine soil on the bed surface. The seed bed is divided into a cooling bed and a hotbed. Cold beds are nursery impotence or nursery pots set in plastic greenhouses. It is a way of using sunlight to raise seedlings. The hotbed is based on the cooling bed, artificial heating equipment, a seedling raising temperature of the seedbed. 2, determine the sowing date. According to the planting season, climatic conditions, cultivation methods, nursery facilities and other factors taken into account to determine the appropriate sowing period. For example, in the open season in spring, the Beijing area is usually sown in mid-February until early March. In the open season cultivation in the autumn, sowing in late July to early August in the south of the Yangtze River, such as Shanghai and Nanjing, has the best effect, while the output in the eastern part of Sichuan is sown in early July. The output is also higher. In areas where the tomato disease has been seriously affected, the sowing date has been appropriately delayed for one to two months, and then higher yields can also be obtained through measures such as dense planting, early picking of the heart, and increase of fertilizer and water. 3, sowing method. Usually broadcast, drill and on demand. Immediately after sowing, the soil should be covered and fine soil should be used to cover the soil. The thickness of the cover soil is about 0.8-1.0 cm, and the thickness should be the same. After planting, use 8 grams of 50% carbendazim WP each time the seedlings are sown and spread on the bed with a thin layer of fine soil to prevent seedling damping-off. Winter and spring nursery beds need to cover the surface of the film. In summer and autumn, nursery beds need to be covered with shade nets or straw. When 70% of the seedlings grow in the top soil, the cover is removed. 4. Management during emergence. In general, the temperature of nursery beds is high, and the conditions for keeping warm are good. After the seeds are first primed, they can be seeded 2-3 days after sowing. Conversely, it takes 5 days or longer to emerge. Seedling management is mainly the control of temperature and light. (1) Management of seedbeds from sowing to emergence. This period refers to sowing until the two cotyledons fully develop. The nursery period of spring cultivated tomatoes in the open season is arranged in the cold season. The bed temperature must be controlled at the temperature of 25-28 degrees Celsius, and the night temperature is 15-18 degrees Celsius. The use of cold or warm nursery, during this period should make full use of solar energy to increase the bed temperature, and use the cover to maintain a high bed temperature. Before the emergence of the general does not lift the film, open the window and let go of the wind. When the young shoots start to appear in the top soil, if the cover is found to be too thin due to overburden, it should be covered once more. Winter seedling temperature management in the following table. (2) Seedling management before emergence to sub-seedling. This period is mainly to adjust the seedbed temperature and humidity, and time seedlings, soil cover, improve lighting conditions, prevention and treatment of seedling diseases. After the two cotyledons of the seedlings are fully developed, the bed temperature should be appropriately lowered, and the temperature can be controlled at 20-25 degrees Celsius during the day and 10-15 degrees Celsius at night to prevent leggy. 4-5 days before seedling separation, in order to adapt to the lower temperature of the seedbed, improve the survival rate after transplantation, and promote seedling, the bed temperature at this time can be reduced by 2-3 degrees Celsius. Cold bed nursery, especially seedbeds and greenhouse nursery, should gradually increase the ventilation during the day to extend the ventilation time, grasshoppers or thin mats also have to gradually cover the late cover, extend the lighting time. Seedling blight or damping-off often occurs during bad seedlings, and proper ventilation and air exchange are not carried out during bad weather. Long-term use of grass cover, film, and other coverings cover the air, causing the air humidity in the seedbed to gradually increase. of. During the period, special attention should be paid to protecting cotyledons; improving lighting conditions; waiting for harmful time seedlings; water and fertilizer management;