How to grow tomatoes in the open air in South China

How to grow tomatoes in the open air in the south? Please give an introduction to guide the open-air cultivation of tomatoes in the south, you can refer to the following methods: first, the quantitative index of tomato high-yield cultivation: tomato temperature requirements: tomato likes temperature, the suitable temperature in daytime is 25 ℃-28 ℃, night 16 ℃-18 ℃. Below 15 ℃, tomato seed germination, pollination and fertilization and tomato turning red were affected: below 10 ℃, the growth was slow, the reproductive development was inhibited, the stem and leaf stopped growing at 5 ℃, 2 ℃ was chilled, and 0 ℃ was frozen to death. The reproductive development was affected when it was higher than 35 ℃, and died of heat due to physiological disorder above 40 ℃. Sufficient light and suitable temperature difference are beneficial to the accumulation and maturity of nutrients, promote the healthy development of plants, prevent overgrowth, enhance the disease resistance and stress resistance of tomato, and increase the yield. Humidity requirements of tomato: the basic principle is that except for the slow seedling stage after germination, emergence and planting, higher temperature and humidity are required, and high humidity is not needed in other periods. In addition to the proper control of water before planting, flowering and maturing, adequate water supply should be ensured in all other stages. The principle of tomato nutrition supply: tomato needs a large amount of fertilizer, and adequate nutrition should be ensured in each period, but there are certain differences in fertilizer demand in each growth period, focusing on nitrogen fertilizer in the early stage, potash fertilizer in the later stage, and phosphate fertilizer throughout the growth period. But the demand for potash fertilizer should be guaranteed throughout the growth period. Under the condition of ensuring the normal growth and development of tomato, low temperature training of tomato can not only improve the heat and cold resistance of the plant itself, but also reduce the cost of heating and heat preservation. In general, the optimum temperature is needed at the turning point and critical period of tomato growth, such as germination, emergence, flower bud differentiation, pollination, fertilization and maturation, as well as after seedling planting, to ensure the appropriate temperature, in order to promote the normal reproductive physiological process and the healing and recovery of growth as soon as possible after injury. Adequate exercise should be done before seedling division and planting to ensure safe passage through the difficult period after injury, and in the normal growth stage, the temperature can be slightly lower. The key to tomato cultivation is to cultivate strong seedlings. The index of strong seedlings is 6 mi 7 leaves, seedling age 60 mi 70 days, 20 mi 23 cm high, 60% Mel 70% flower buds. 2. To prepare nutritious soil according to a certain proportion, it is required that the porosity of nutritious soil is about 60% Ph6-7, containing more than 100 mg / kg of available phosphorus, more than 100 mg / kg of available potassium, 150 mg / kg of available nitrogen, loose, fertilizer and water retention, and complete nutrition. Spread the prepared nutrient soil evenly in the seeding bed (10 cm thick), or in the seedling tray. Third, seed treatment. Tomato seed disinfection treatment. There are two methods: (1) soak the seeds in warm soup, that is, soak the seeds in clean water for 1-2 hours, then remove the seeds and put them in hot water at 55 degrees Celsius, keep the water temperature for 15 minutes, and then continue to soak the seeds for 3-4 hours. When soaking seeds in warm soup, it is usually one seed and two parts of water; stir constantly and quickly so that the seeds are uniformly heated to prevent scalding seeds; third, keep heating water constantly and keep the water temperature of 55 degrees Celsius. It can prevent the occurrence of leaf mold, canker, early blight and other diseases. (2) soak the seeds with trisodium phosphate, that is, soak the seeds in clean water for 3-4 hours, remove and drain, then soak them in 10% trisodium phosphate solution for 20 minutes, remove and wash. This method has obvious effect on tomato virus disease. Freeze the potato tubers and then slowly thaw them, then squeeze the juice and soak the tomato seeds in potato juice overnight. The next day, a thick cloth without fluff is dipped in the juice, and the soaked seeds are loosely placed on it so that the seeds do not touch each other. Cover them with polyethylene film to avoid dryness, but keep them breathable, and then put them in a warm place (not heated). After the seeds germinate, insert them into the soil to raise seedlings. This method of accelerating germination can mature 2-3 weeks earlier than ordinary germinated tomatoes. Fourth, sprouting and sowing amount should be determined. General tomato seeds contain about 300 seeds per gram, according to the planting density, generally 20-30 grams per 667 square meters of field seeds. Each square meter of seeding bed can sow 10-15 grams. If the seed germination rate is less than 85%, the sowing rate should be increased appropriately. Determine the sowing date. The suitable sowing date was determined according to the planting season, climatic conditions, cultivation methods, seedling facilities and other factors. For example, in open field cultivation in spring, seedlings are usually sown in Beijing from mid-February to early March. For open field cultivation in autumn, the effect of sowing in the south of the Yangtze River, such as Shanghai and Nanjing, is the best from late July to early August, while the yield of sowing in the eastern part of Sichuan is higher in early July. The output is also higher. In some areas where tomato diseases are serious, the sowing date can be postponed for 1-2 months, and then higher yield can be obtained through close planting, early coring, increasing fertilizer and water and other measures. Seeds can be sowed directly after treatment, but it is best to accelerate germination and sow. When accelerating germination, usually untreated seeds need to be soaked in warm water for 6-8 hours to fully expand, and then placed at a temperature of 25-28 degrees Celsius for 2-3 days. On the other hand, the seeds soaked with chemicals only need to rinse the seeds with clean water and then sprout directly. In the process of sprouting, it is necessary to provide appropriate temperature, moisture and air, so that the seeds should be checked and turned frequently to make the seeds loose, and rinse with clean water 1-2 times a day to update the air and maintain humidity. It is best to use a thermostat to promote budding. After accelerating the germination of the seeds, the seedlings emerge quickly and neatly after sowing, which is conducive to the cultivation of robust seedlings. Sowing method. There are usually broadcast, broadcast and on-demand. The soil should be covered immediately after sowing, and sifted fine soil should be used for covering. The thickness of the covered soil is about 0.8-1.0 cm, and the thickness should be consistent. After sowing, 8 grams of carbendazim 50% wettable powder mixed with fine soil is scattered evenly on the bed surface after sowing, which can prevent the occurrence of seedling quenching disease. The surface of the seedling bed should also be covered with plastic film in winter and spring. The surface of the seedling bed should be covered with sunshade net or straw in summer and autumn, and the mulch should be removed when there is 70% seedling top soil. 5. under the general situation of seedling management, if the temperature of the nursery bed is higher, the heat preservation condition is good, and the seeds are accelerated first, they can emerge 2-3 days after sowing, on the contrary, it will take 5 days or more to emerge. The management of seedling stage is mainly the control of temperature and light. (1) seedbed management from sowing to emergence, which refers to the period from sowing to the full expansion of two cotyledons. The nursery period of tomato cultivated in open field in spring is arranged in the cold season, and the bed temperature must be controlled at 25-28 degrees Celsius during the day and 15-18 degrees Celsius at night. If a cold bed or hotbed is used to raise seedlings, solar energy should be fully utilized to increase the bed temperature and mulch should be used to maintain a higher bed temperature. Generally do not uncover the film and open the window before emergence. When the young buds begin to emerge from the top soil, if the cover soil is too thin and the top shell phenomenon is found, it should be covered with soil again immediately. The temperature management in winter and spring nursery period is shown in the table below. (2) seedbed management from emergence to pre-seedling division. The main purpose of this period is to adjust the temperature and humidity of seedling bed, timely interseedling and soil mulching, improve light conditions, prevent and control seedling diseases, and so on. After the two cotyledons of the seedlings are fully expanded, the bed temperature should be reduced appropriately, which can be controlled at 20-25 degrees Celsius during the day and 10-15 degrees Celsius at night to prevent excessive growth. 4-5 days before seedling separation, in order to adapt to the lower temperature of the seedling bed, improve the survival rate after transplantation, and promote slow seedling, the bed temperature can be further reduced by 2-3 degrees Celsius. Raising seedlings in cold beds, especially in hotbeds and greenhouses, should gradually increase ventilation vents during the day, prolong ventilation time, and gradually uncover grass or thin mats early and late to prolong light time. The disease of standing blight or quenching which is easy to occur in the seedling stage is often caused by the gradual increase of air humidity in the seedbed without proper ventilation and covering with grass grass and thin film for a long time in bad weather. During this period, special attention should be paid to protecting cotyledons, improving light conditions, equal harmful time seedlings, water and fertilizer management, and reasonable soil mulching. 6. growth period management should pay attention to the management of growth period, including ploughing and weeding, water storage and soil moisture conservation, setting up and binding vines, pruning and branching, removing old leaves, ventilation and transparent light, strengthening the prevention and control of diseases and insect pests, strengthening temperature management, and so on. Among them, tomato diseases are mainly virus disease, bacterial wilt, early blight, late blight and so on; pests are mainly cotton bollworm, aphids and so on. Tomato diseases can be prevented and difficult to treat, so prevention should be given priority to. The prevention and control methods of virus diseases are as follows: selection of disease-resistant varieties, seed disinfection, seed stubble, prevention and control of aphids, early planting and so on. Temperature management is to appropriately increase the ventilation rate of the shed during the day to keep the temperature in the shed at about 25 ℃. The night temperature is kept between 10-13 ℃. At the beginning of the vent, the vent should be from small to large, from less to more, and gradually reduce or close the tuyere after the temperature drops in the afternoon. Do a good job of fertilizer and water management. Tomatoes generally do not need to be watered during the summer and autumn rainy season, but they should also be watered properly when 2-3 ears are ripe. According to the growth of tomato plants, topdressing should be applied timely to promote fruit development and protect flowers and fruits. Generally, Gymboree microbial fertilizer can be applied as base fertilizer, and Gymboree seedling strengthening agent and Gymboree Zengtianling can be applied as topdressing to make it look more beautiful and delicious. Conditional application of bean cake, cottonseed cake and other cake fertilizer. 7. Pick the fruit at the right time. There are four stages of tomato ripening: green ripening, discoloration, ripening and ripening. Storage and preservation can be harvested in the green ripening period. The transport sale can be picked during the discoloration period (the fruit turns red at 1pm 3). On-the-spot sale or self-feeding should be picked during the ripening period, that is, when the fruit turns red above 1 / 3. It should be picked and handled gently when harvesting, and it is best to pick without fruit stalks, so as to prevent the fruits from being stabbed each other during shipment. Before the first frost, if there are unripe green fruits, they should be stored in the greenhouse after harvest, and the fruits should be listed after ripening, which not only prolongs the supply period, but also increases the economic benefits. It is not suitable to use hormone to stimulate fruit coloring in the post-ripening period, and it can be boxed and sold after selection. Its advantage is that it not only reduces the production cost, improves the fruit quality, but also ensures the safety of consumers. 8, pest control 1, tomato peel control this is a physiological disease, also known as tendon rot or stripe rot or with rot, the main harm to the fruit, the following to introduce to you, there are two common types. One is browning. The young fruit began to occur, mainly harming 1 to 2 ears, local browning appeared on the fruit surface during the fruit expansion period, the fruit surface was uneven, some fruits showed tea-brown hardening or necrotic spots, and the diseased fruit was dissected. It was found that the vascular bundles in the pericarp showed tea-brown strip necrosis, hardening of the core or browning of the pulp, losing commercial value. The second is the white variant. It mainly occurs in the period when the green ripe fruit turns red, the disease is that the fruit coloring is uneven, the light fruit shape does not change much, the heavy part near the fruit stalk appears green protuberance, the red part is slightly sunken, and the diseased part has waxy luster. The diseased fruit is found to be in the shape of "bran heart", the vascular tissue of the flesh is dark brown, and the light vascular bundles turn brown and necrotic, and the browned parts do not turn red, the dull meat hardens, and the quality is poor. The food is insipid and tasteless. In the seriously diseased fruits, the vascular bundles of the pulp were all dark brown, some of the fruits were hollow, and the bright face was uneven in red and green. The vegetable farmer said that he belonged to the white variant. Tomato tendon rot is generally not seen on the stem and leaf, but the stem 70 cm away from the root shows brown pathological changes in the transport tissue of the stem, which has been destroyed, leading to the above disease in the fruit, which is different from the virus disease. Etiology: as it is a physiological disease, the degree of damage depends on the variety, sunshine hours, light intensity and the proportion of nitrogen, phosphorus and potassium in the soil. Prevention and control methods: mainly make efforts in management, appropriately increase the light to scientifically determine the sowing and planting date, and adopt formula fertilization. Those who have the above symptoms can be sprayed with multi-element fertilizer. Techniques for prevention and control of cucumber diseases and insect pests in protected areas (1) physical control of high temperature and disinfection of soil: during the period of high temperature in three summers. After pulling seedlings in the spring protected field, first clean the fields and remove the diseased plants, diseased leaves and diseased roots from the field and bury or burn them; apply 50-100kg of lime and 1000 kg of crushed rice straw (or wheat straw) per mu evenly on the surface; turn the soil 66 cm deep, super-high ridge 33 cm, irrigation, so that the ditch is always filled with water; plastic film and airtight shed for 7-10 days can control cucumber Fusarium wilt, blight, root-knot nematode and so on. Baking soda or high-fat membrane to control powdery mildew: when powdery mildew just occurs, spray 500 times of baking soda once every 3 days for 5-6 times, which can not only prevent powdery mildew, but also decompose carbon dioxide and increase cucumber yield. Or use 27% high-fat emulsion 80-100 times, spray once in 6 days, 4 times in a row. (3) yellow board or silver gray film to avoid aphids. (2) Biological control and disease prevention: for powdery mildew, anthrax and black spot, when individual spots first appear, you can spray 200 times of 2% agricultural antibiotic 120 or agricultural antibiotic B0-10 water agent, spray once every 6-7 days, and spray 3-4 times successively, and it can also treat gray mold and downy mildew. Bacterial diseases, such as angular spot, can be sprayed with 100 times of Nongkang 751 water agent every 5-6 days for 2-3 times. Insect control: when cucumber aphids occur, spray Shaoguan mycin 200 times, add 0.01 neutral detergent, or spray with 0.65% anisinin 200 ml, plus 60-80 kg of water. Tea yellow mite can spray 20% compound liuyangmycin 800-1000 times solution, spray once every 6-7 days, 2-3 times in succession. (3) Pesticide control for cucumbers in protected areas with high efficiency and low residual pesticides can be selected for proper control. Downy mildew can be treated with 7% carbendazim dust or 80% Damei 45 wettable powder or 72% dew wettable powder; Botrytis cinerea uses 5% carbendazim dust or 50% carbendazim or 50% carbendazim 2 1000 times; corner spot uses 5% anti-bacterial dust or carbendazim; scab can use anti-scab dust or 40% Foxing EC; anthracnose uses 8% carbendazim dust or 80% anthrax Fumei wettable powder. Aphids and whiteflies can be controlled with aphids, whitefly dust or 10% imidacloprid wettable powder. 2. Tomato fruit is hollow for a reason. Tomato hollow fruit refers to the fruit with holes between the peel and the gelatinous matter of the pulp. Although the hollow fruit has little effect on the yield of tomato, it will seriously affect its commerciality and reduce the economic benefit, which can not be ignored in the production. Tomato hollow fruit is a physiological disease, which is easy to occur in varieties with a small number of ventricles. There are many reasons for the formation of tomato hollow fruit, such as improper spraying time of hormone, lack of light, insufficient watering in peak period, too much fruit left, lack of nutrition supply and so on. In order to avoid the occurrence of hollow fruit, tomato varieties with more ventricles should be selected in cultivation, and regulators should be used rationally. When the flowers of each inflorescence have 2 scarps and 3 blossoms, the concentration of 15ppm~25ppm should be sprayed, and attention should be paid not to repeat them. In addition, sufficient base fertilizer should be applied in cultivation, and formula fertilization technology should be adopted to topdressing and watering in time in the peak period to meet the nutrient needs of plants. The growth trend of each tomato variety is different, so it should be pinched in time according to the characteristics of each variety, so that the vegetative growth and reproductive growth of the plant can be developed in a balanced way. Click to get more tomato planting techniques click to get more vegetable planting techniques