Vegetable planting technology in greenhouse 1. Construction of greenhouse 1. Types and structures of scaffolding. There are many types and structures of plastic greenhouses. At present, there are two kinds of prefabricated galvanized thin-walled steel pipe (referred to as steel pipe greenhouse) and bamboo-wood circular arch greenhouse which are widely used. It is mainly used for early-maturing cultivation in spring and delayed cultivation in winter in Natsuna, such as tomato, sweet (hot) pepper, eggplant and cucumber, as well as seedling raising and hybrid seed production. There is also a bamboo shed, which is often used alone or in combination with the greenhouse (that is, the greenhouse is covered with a shed) for seedling raising and early-maturing cultivation of eggplant and melon vegetables in winter and spring. There are two specifications for steel pipe greenhouses: one is that the center is 2.2 meters high, the width span is 4.5 meters, the length is 20 meters, and the area is 90 square meters; The other is that the center is 2.5 meters high, 6 meters wide and 30 meters long, with an area of 180 square meters. The service life is generally 15 years. In order to reduce the production cost, bamboo shed can also be used. The scaffolding is made of bamboo or small logs, with a height of about 2 meters and a width of 4-5 meters, and its general service life is 3 years. (II) Covering materials: There are the following kinds of covering materials for greenhouses: 1, and ordinary film: made of polyethylene or polyvinyl chloride, with a film thickness of 0. 1 mm, which is colorless and transparent. The service life is about half a year. 2. Multifunctional long-life film: It is made by adding proper amount of anti-aging materials and surfactants during polyethylene blow molding. The multifunctional membrane produced by Xinguang Plastic Factory in Zhejiang Province has a width of 7.5 meters and a thickness of 0.06 mm, its service life is twice as long as that of ordinary membrane, and its greenhouse temperature at night is1-2℃ higher than other materials. Moreover, the film is not easy to form water droplets, with good covering effect, low cost and high benefit. 3, grass quilt, grass fan: woven from straw, good thermal insulation performance, is a night thermal insulation material. 4. Polyethylene high foaming film: it is a white plastic film with many bubbles, with a width of 1 m and a thickness of 0.4-0.5 cm. It is light and can be rolled up, and its thermal insulation is similar to that of grass quilt. 5. Non-woven fabric: a kind of polyester filament, which is not woven and spun. There are two kinds of black and white, and they have different densities and thicknesses. The common specification is 50g/? Besides heat preservation, it is often used as a sunshade net. 6. Sun screen: a plastic woven screen. Commonly used are black and silver gray, and there are several density specifications, and the shading rate is different. It is mainly used for sunshade and rainproof in summer, and can also be used for thermal insulation and covering in winter. (3) Greenhouse construction: choose a place with sunny, sheltered, high dryness, good drainage and no soil infectious diseases to build a greenhouse. (4) Maintenance of plastic film: When the film is buckled, the mechanical damage of the shed film should be avoided as much as possible, especially for the bamboo shed. Before the film is buckled, the protruding part of the shelf surface should be flattened or wrapped with old cloth. When fixed by spring, a layer of old newspaper should be padded at the card slot. In addition, attention should be paid to avoid long-term contact between old and new films, so as not to accelerate the aging of new films. Be careful when ventilating. Freezing or exposure of the film will promote the aging. When the steel pipe is exposed to the sun in summer, the temperature can rise to 60-70℃, thus accelerating the aging and crushing of the film. In the process of using the film, it is inevitable that there will be holes, so it should be repaired with adhesive or tape in time. Second, the environmental characteristics and control greenhouse is covered with plastic film, which forms a special microclimate that is relatively closed and different from the open field. To cultivate vegetables in greenhouse, we must master the characteristics of the environment in greenhouse and take corresponding control measures to meet the conditions of vegetable growth and development, so as to obtain high quality and high yield. (1) Environmental conditions in the greenhouse:

1, illumination: it depends on the solar radiation intensity outside the shed, the optical characteristics of the covering material and the pollution degree. The transmittance of new plastic film is 80-85%, and the transmittance of old film polluted by dust and mud is often below 40%. Water droplets condensed on the film surface can reduce the illumination in the shed by10%-20% due to the diffusion of water droplets. The shed frame, film pressing line and the frame material of tall vegetables will be shaded, so the factors that weaken the light in the shed should be avoided and eliminated as much as possible in the management of the shed. 2. Temperature: (1) Temperature variation law: The daily variation trend of temperature in the greenhouse is the same as that in the open field, but the temperature difference between day and night varies greatly. There is plenty of sunlight during the day. If the temperature in the film closed shed rises rapidly, the highest temperature can reach 40-50℃, which is more than 20℃ higher than that outside the shed. On rainy days, the warming effect is poor, and the lowest temperature in the shed at night is generally1-3℃ higher than that outside the shed. The ground temperature in the shed is more stable than the air temperature, usually10-20℃. The temperature in the greenhouse also varies with different locations. The greenhouse is horizontally distributed as high in the middle and low on both sides, so the plants in the middle of the greenhouse are often taller than those on both sides. The greenhouse is distributed vertically. When the sun shines during the day, the temperature is high at the top and low at the bottom, but it is the opposite at night and cloudy days. (2) Inversion phenomenon: In a polyethylene-covered greenhouse, there is a breezy and sunny night in winter, and the temperature inside the greenhouse is sometimes lower than that outside the greenhouse. The reasons are as follows: at night, the temperature outside the shed is higher than that at the lower place. Due to the disturbance of wind, the heat can be supplemented from the upper air outside the shed, but it can't be obtained in the shed because of the obstruction of the cover; In winter, it is cool during the day, and the soil stores less heat. In addition, the polyethylene film has higher long-wave emissivity, slightly poor thermal insulation, large effective heat radiation from the ground and more heat dissipation, which leads to the phenomenon that the temperature inside the shed is lower than that outside the shed. (3) Temperature control: The temperature control of the greenhouse is mainly carried out by ventilation and heating. It is the most commonly used method to reduce and control the air temperature in the shed during the day by uncovering the film. Using sunshade materials can reduce the light receiving amount of the shed and also prevent the air temperature in the shed from being too high. In winter, in order to reduce heat loss and improve air temperature and soil temperature, the shed film should be tightly covered as much as possible. Wind barriers can be set up around the greenhouse, and small sheds can be set up in the greenhouse, and then multi-layer coverage such as grass slices, non-woven fabrics and foamed plastics can be adopted. Heating measures can also be adopted to increase the temperature, such as using electric hot wires to increase the soil temperature, and in conditional areas, the waste heat of factories, geothermal water or coal stoves can be used to increase the temperature in the shed. The water bag (plastic bag filled with water) is built in the greenhouse. By using the characteristics of high specific heat of water, the water bag absorbs a large amount of solar energy during the day, converts it into heat energy, stores it, and gradually releases it at night, which can improve the greenhouse temperature. 3. Regulation of Air Humidity (1) The change law of air humidity in greenhouse: the plastic film is closed, the exchange between the air inside the greenhouse and the outside air is hindered, and the water vapor from soil evaporation and leaf transpiration is difficult to disperse. Therefore, the humidity in the shed is high. During the day, the relative humidity of the air in the greenhouse is 70-80% under the condition of ventilation. It can reach more than 90% on rainy days or after irrigation. The relative humidity of air in the shed decreases with the increase of temperature, and it is often 100% at night. Wet air in the shed condenses into water film or water droplets after being cold and adheres to the inner surface of the film or plants. (2) Control of air humidity: Excessive air humidity in the greenhouse not only directly affects the photosynthesis of vegetables and the absorption of mineral nutrients, but also facilitates the germination and infection of pathogen spores. Therefore, the relative humidity in the shed can be effectively reduced by ventilation and promoting the exchange of high humidity air in the shed with low humidity air outside. Heating the hot line in the shed can also reduce the relative humidity. Using drip irrigation technology combined with plastic film mulching cultivation to reduce soil moisture evaporation can greatly reduce air humidity (about 20%). 4. Air composition in the shed: Due to the film covering, the air flow and exchange in the shed are limited. In the case of tall vegetable plants and lush foliage, the concentration of carbon dioxide in the air in the shed changes dramatically. Before sunrise in the morning, due to crop respiration and soil release, the concentration of carbon dioxide in the shed is 2-3 times higher than that outside the shed (about 330PPM); After 8-9 o'clock, with the enhancement of leaf photosynthesis, it can be reduced to below 100PPM. Therefore, after sunrise, ventilation should be carried out as appropriate to replenish carbon dioxide in the shed in time. In addition, artificial carbon dioxide fertilization can be carried out with the concentration of 800-1000 ppm, which can be used after sunrise and before ventilation. Artificial application of carbon dioxide, in the case of weak light and low temperature in winter and spring, has a very significant effect on increasing production. In the low temperature season, greenhouses are often sealed and insulated, and it is easy to accumulate toxic gases, such as ammonia, nitrogen dioxide, sulfur dioxide, ethylene and so on. When the ammonia gas in the greenhouse reaches 5PPM, water-soaked spots will appear at the tip of plant leaves, and then turn black and die; When nitrogen dioxide reaches 2.5-3 ppm, irregular green and white spots appear on the leaves, and in severe cases, all the leaves are bleached except the veins. The production of ammonia and nitrogen dioxide is mainly caused by improper use of nitrogen fertilizer. The production of carbon monoxide and sulfur dioxide is mainly caused by heating with coal fire, incomplete combustion or poor quality of coal. Because the aging of plastic film (plastic pipe) can release ethylene, causing premature senescence of plants, so excessive use of ethylene products is also one of the reasons. In order to prevent the accumulation of harmful gases in the shed, fresh manure can not be used as base fertilizer, nor can it be used as topdressing; It is forbidden to use ammonium carbonate as topdressing. When urea or ammonium sulfate is used as topdressing, it should be watered or covered with soil in time after hole application. The amount of fertilizer should be appropriate and not excessive; Proper ventilation is also needed in low temperature season to eliminate harmful gases. In addition, the quality of coal used is better and it should be fully burned. If possible, use hot air or hot water pipes to heat up and discharge the burnt waste gas outside the shed. 5. Soil moisture and salinity: The distribution of soil moisture in greenhouse is uneven. The soil near the two sides of the shed has more water infiltration outside the shed and higher humidity of water droplets flowing on the shed film. The middle part of the shed is relatively dry. Cucumber and eggplant planted in greenhouse in spring, especially those cultivated with plastic film, often suffer from insufficient soil moisture, which seriously affects the quality. It is best to lay hose drip irrigation belt and apply fertilizer water at any time according to actual needs, which is an effective measure to increase production. Due to the long-term coverage of the greenhouse and the lack of rainwater leaching, the salt moves from bottom to top with the groundwater, which is easy to cause excessive accumulation of salt in the cultivated soil and cause salinization. Therefore, it is necessary to pay attention to proper deep tillage and application of organic fertilizer to avoid long-term application of fertilizers containing chloride ions or sulfate ions. Topdressing should be light, and it is best to test soil and fertilize. Every year, there should be a certain period of time without covering the film, or in summer, only covering the sunshade net for shading cultivation, so that the soil can be leached by rain. When soil salinization is serious, flooding can be used to suppress salt, and the effect is very good. In addition, using soilless culture technology is a fundamental measure to prevent soil salinization. Third, the arrangement of annual stubble of vegetables in greenhouse is only the early cultivation of eggplant in spring, which is only used for 4-5 months a year, and the utilization rate and benefit are not high. If the greenhouse is also used for cultivation, seedling raising and seed retention in autumn, winter and summer, the production benefit can be improved. (1) Seedling-cultivation type; It is characterized by seedling raising in winter → early maturity cultivation in spring → seedling raising in summer → autumn and winter cultivation. In winter, seedlings of solanaceous fruits, melons and beans are generally cultivated from 1 1 month to the middle and late March of the following year. Planting in the middle and late March, and early-maturing cultivation in spring. Cultivate seedlings from June to August in summer, such as cabbage, cauliflower and tomato. Autumn and winter cultivation of autumn tomatoes, cucumbers, leafy vegetables, celery, onions and garlic. (2) Cultivation type: mainly cultivated vegetables, combined with seedling raising. There are two main forms: one is to cultivate eggplant, tomato, cucumber and pepper in early spring, fast-growing vegetables in summer, cucumber, tomato, cabbage and cauliflower in autumn and celery, spinach, lettuce and onion and garlic in winter; The second is intercropping, in which tomatoes and peppers are cultivated early in spring, and loofah is planted next to the arch pole in the greenhouse in April-May, so that it can climb along the arch pole, or in the later period of tomato growth, wax gourd is planted in the border, and the vines are climbed by the tomato bracket; Planting lettuce and cabbage in autumn; Seedling raising is carried out in winter. (3) Seed-reserved seed production: There are two main ways: one is to keep seed production of eggplant and melon in spring, and its stubble mode is to raise seedlings in winter → keep seeds in spring → cultivate celery and cabbage in autumn; One is to collect and reserve seeds mainly for self-incompatibility of Cruciferae in winter and spring, raise seedlings in summer and cultivate eggplant and melon vegetables in autumn. Four, cultivate vegetables in greenhouse. (1) Early-maturing cultivation of eggplant and melon vegetables in Natsuna in spring is the most common project for greenhouse cultivation. Open field cultivation is generally planted from late March to mid-April, and harvested from early May to July. Greenhouse cultivation can be planted in1-March in advance and harvested from late March to July. Early listing, higher yield, longer flowering and fruiting period and obvious economic benefits. In addition, according to the market demand, we can sow amaranth, auricularia, water spinach and other warm green leafy vegetables in advance and go on the market in advance. 1, variety (combination) selection: Zaofeng, Japanese Red× Aihong are selected as early-maturing tomato varieties; Zheza No.5, Sukang No.4 and No.5 are selected as the medium-mature varieties, and excellent varieties with early maturity, disease resistance, high yield and marketability are selected as the sweet peppers. Pepper: chicken feet× Jilin F 1, Zaofeng 1; Sweet pepper: Add No.3; Eggplant: Min eggplant 1, Pingtung eggplant; Cucumber: Jinchun No.2 and No.3, etc. 2. Planting: Before planting, cover the shed with plastic film/0/0 day. Apply 3000 kg of manure or decomposed garbage manure, 2000 kg of human excrement and urine, and 50 kg of compound fertilizer per mu, and apply it in deep ditches or all layers, and turn it into the soil. Tomatoes are planted in a greenhouse with four rows of furrows 1.5 m, with a row spacing of 75 cm and a plant spacing of 20-30 cm, with 2,500-3,000 plants per mu. There are 3000 plants of pepper per mu. Eggplant spacing is 40-50 cm, and 2000-2400 plants are planted per mu. 2,000-2,400 cucumbers are planted per mu. 3. Field management: (1) Temperature management: No ventilation within one week after planting, mainly heat preservation, especially eggplant and cucumber, which should be kept at a high temperature to facilitate seedling return. After returning seedlings, it is necessary to maintain a high temperature. The optimum temperature for tomato seedling growth is 20-25℃ during the day and10-15℃ at night. The optimum temperature for eggplant growth is 20-30℃, and when the temperature is lower than 15℃, it will cause poor pollination and fertilization. The optimum growth temperature of sweet (spicy) pepper is 25-28℃; The temperature of cucumber is 28-30℃, and the temperature at night should not be lower than 10℃. The temperature rises gradually in the middle and late May, and the skirt film can be gradually removed. The film should be closed at 9: 00-10 at seedling stage and covered after16 in the afternoon. (2) Fertilizer and water management: after planting and returning seedlings, raise seedling fertilizer with thin human excrement or livestock fertilizer. Tomato, ① the first ear fruit expansion stage, compound fertilizer 10 kg/mu; The second-third ear fruit begins to swell, and the compound fertilizer is 30 kg/mu; The fourth-fifth ear fruit begins to swell, and the compound fertilizer is 20 kg/mu. (2) After applying fertilizer to sweet (spicy) pepper seedlings, during the whole growth period, keep the field moist, not dry, not accumulating water, and apply thin fertilizer frequently. Generally, topdressing is performed once every two harvests, with compound fertilizer 10 kg/mu, and the fertilization amount is increased by 20 kg/mu in the full fruit stage. Eggplant topdressing is similar to pepper, and cucumber topdressing is done once every two harvests. (3) Erection and pruning: tomatoes and cucumbers should be planted with bamboo to support the plants and lead vines to the shelves, which is beneficial to the results. Tomato should be pruned with two poles, the first lateral bud above the first flower ear should be retained, and all the axillary buds and branches below should be removed. The first flower and the 1 branch below the fruit of eggplant are left, and all others are removed. Sweet (spicy) pepper has a regular flowering and fruiting. When the growth, flowering and fruiting are too strong and the plant growth potential is small, the upper flowers and fruits should be removed to facilitate the normal growth of the lower flowers and fruits. (4) flower protection and fruit protection: when the temperature is low in spring, tomatoes and the first and second panicles need hormones to protect flowers and fruits, so as to increase the early yield, and 40PPM anti-falling agent is used to spot pedicels; Eggplant should be spotted before flowering1-2 days (trumpet-shaped) or sprayed with anti-falling agent 15PPM; Pepper can also be sprayed with anti-falling agent. The flower and fruit protection treatment should be carried out at the temperature below 15℃ and above 15℃, and it should not be treated if there is sufficient sunlight. The concentration should be strictly controlled and not too high to avoid side effects.

(II) Delayed cultivation in autumn and winter in Natsuna The general harvest period of delayed cultivation in autumn and winter in Natsuna is10 ─1February, which can be extended to the Spring Festival if it is preserved, with high economic benefits. 1, cultivation season and variety: (1) tomato, sowing in early July, seedling age of 30 days, planting from late August to September, harvesting in10-1February. The varieties are Zheza 7 and Zaofeng. (2) Cucumber: direct seeding from the end of July to mid-August, and harvesting from September to 1 1 month. Varieties are Jinyan No.4, Jinchun No.4, Autumn Cucumber 1, Xiafeng, etc. (3) Autumn tomatoes, flowers that bloom before mid-September, often fall off because of high night temperature, while flowers that bloom after 10 are not easy to bear fruit because of low temperature. Therefore, it is necessary to spray flowers with 10─ 15PPM, or coat pedicels with a concentration of 40PPM to prevent flowers from falling and fruits from falling. (3) In addition to high-stalk vegetables such as melons and eggplant, leafy vegetables with high economic value, such as auricularia, water spinach, celery, lettuce, etc., can be cultivated in the greenhouse in advance of spring, delayed in autumn and overwintering, so as to avoid freezing injury, promote growth, increase yield, extend supply and go on the market out of season, with good economic benefits. Leaf vegetables that like temperature and heat tolerance, such as auricularia auricula and water spinach, can be planted in greenhouse in September-10, and then covered with heat preservation in the later stage, put on the market in advance, and with conventional cultivation, basically achieve annual supply. Lettuce and other vegetables that like to be cold but are less frost-tolerant are best planted in the open field from late August to early September and from March to April in spring. If they are planted in 1 1 month to March of the following year, they will be cultivated in greenhouses. (4) Shading and rainproof seedling cultivation in summer. From late June to early August in southern China, strong light and high temperature, thunderstorms and typhoons and rainstorms have seriously affected vegetable production and early autumn vegetable seedling. In recent years, the application of sunshade nets and non-woven fabrics has promoted the greenhouse to play a role in seedling cultivation and cultivation in summer. 1, the function of shading and covering in greenhouse (1) Shading function: Shading net significantly reduces the light intensity in the greenhouse. The greater the density specification, the better the shading effect. The shading effect of black in the same specification is better than that of silver gray. Generally, the shading rate of black is 42%-65%, and that of silver-gray is 30%-42%. (2) cooling effect: the temperature in the greenhouse is reduced due to the sunshade net covering, especially in the surface and soil tillage layer. The temperature in the upper part of the greenhouse is as high as 37-40℃ in the morning 10-2 pm, while the temperature around the surface plants is 22-26℃ and the soil temperature is between18-22℃, which is suitable. (3) Moisture conservation and rainstorm prevention: evaporation in the shed is reduced, soil water content is higher than that in the open field, and topsoil is moist. Because the sun-shading net has certain mechanical strength and is dense, it can decompose the rainstorm into drizzle, avoid the vegetable leaves from being injured by the rainstorm, and the soil is not easy to harden, with large porosity and good ventilation. It is better to cover the sun-shading net with plastic film in the greenhouse. 2. Precautions for Shading and Covering Cultivation (1) Choose suitable shading nets according to the types of vegetables. Usually, black shading nets are used for short-term covering of green leafy vegetables in summer and autumn, and silver-gray shading nets are used for seedling raising in autumn and winter in summer, which can avoid aphids. Eggplant should be planted or cultivated later, and it is best to use net film together. (2) Coverage period: Generally from July to August, the light intensity at other times is suitable for vegetable growth, and it is not necessary to cover it if there is no heavy rain. (3) Shading management: Shading nets can't be covered on the scaffolding for a long time, especially black shading nets. Only at noon on sunny days in summer and autumn, the light intensity under the nets will reach near saturation, and it is best to cover them at 10-10 in the morning and uncover them at 4-5 in the afternoon. 3-4 days before uncovering the net, the time for covering the net should be gradually shortened, so that the seedlings and plants can gradually adapt to the open environment. (5) The local successful experience of soilless cultivation of vegetables in greenhouses: soilless cultivation of leafy vegetables, annual cultivation of lettuce, 8-9 crops a year, annual yield per mu 1 10,000 kg, the growth period from high to low with the temperature, generally about 20-40 days. Tomatoes can be planted in spring and summer in a year, and the annual yield per mu can reach 1 10,000 kg. Cucumber can be cultivated all year round, with good economic benefits. V. Prevention (correction) of pests and diseases and physiological obstacles Vegetables are planted in greenhouses most of the time, especially in winter, which provides suitable ecological conditions for the overwintering reproduction of pests and diseases, and makes vegetable pests and diseases and physiological obstacles increasingly serious. Therefore, the prevention and control of pests and diseases and overcoming the physiological obstacles of crops are the key to the success of vegetable cultivation in greenhouse. In addition to timely control of pests and diseases in various cultivated varieties and periods, chlorothalonil is fumigated irregularly to eliminate germs. Control of underground pests with carbofuran. (1) Physiological obstacles of greenhouse cultivation and its corrective measures 1, high temperature physiological obstacles: mainly affecting flower bud differentiation, such as the increase of male flowers and the decrease of female flower differentiation in cucumber under high temperature and long sunshine; When tomato and pepper flower buds differentiate, they encounter high temperature, resulting in smaller flowers and poor development. ① Sunburn: the main symptom: at the initial stage, the leaves become milky white after fading, and finally turn yellow and die. (2) Fallen flowers and fruits, resulting in deformed fruits. High temperature, especially high temperature at night, not only delays the differentiation of female flowers in the first inflorescence of tomato, but also affects the normal physiological function of stamens, which can not pollinate normally, causing flower drop and fruit drop. ③ Affect the normal pigment formation: The high temperature hazard in fruit ripening stage is poor coloring. When tomatoes are ripe, the lycopene formation is slow when the temperature exceeds 30℃. When the temperature exceeds 35℃, lycopene is difficult to form, and the fruit appears several variegated fruits with alternate colors of yellow and red. Preventive measures: mainly to strengthen ventilation, so that the leaf surface temperature drops. Covered with sunshade net, you can also spray with cold water to reduce the shed temperature. 2. Physiological obstacle of toxic gas Ammonia poisoning: When the concentration of ammonia gas reaches 0.1%-0.8% in the air, it can harm vegetables. If the temperature is high in sunny days and the concentration of ammonia gas is high,1-2 hours can lead to the death of cucumber plants. Prevention and control measures: organic fertilizer should be fully matured and applied, and chemical fertilizer should be applied less frequently. (2) Typical physiological disorder symptoms of cucumber and tomato and corrective measures: 1, cucumber vine grows excessively; The flower tops, and the internodes near the growing point are shortened, forming a hybrid flower cluster, and the top of the melon seedling does not produce a heart leaf but presents a flower with a head; Yellowing leaves and acute wilting. Cause: Partial application of nitrogen fertilizer. Low temperature in early spring, large temperature difference between day and night, insufficient sunshine, poor root activity and insufficient soil nutrients during seedling raising. Prevention and control measures: timely transplanting, early cover with a small arch shed to raise the temperature. Strengthen ventilation, apply fertilizer correctly, and manage moisture, temperature and sunshine. 2, cucumber, tomato abnormal fruit tomato has overnutrition and too much nitrogen and phosphorus during flowering, especially in winter or early spring. Before and after flower bud differentiation, abnormal fruit will appear when it encounters a low temperature of 6-8℃ for a few days. When the concentration of hormone is too high, or the temperature is too low during treatment, the light is insufficient, the air is dry, or the nutritional conditions are extremely poor, the flowers that were supposed to fall are treated with hormone, which inhibits abscission, but the obtained photosynthetic products are less granular.