Do potted plants need greenhouses? Do potted plants need greenhouses? knowledge

Greenhouse, also known as plastic shed, is an arched shed facility covered with plastic film and a simple shed covered with plastic film without heating. Compared with the glass greenhouse, it has the advantages of simple structure, convenient construction and disassembly and less investment. Disadvantages are poor heat preservation effect, rapid temperature rise and fall, and large daily temperature difference. According to China's national conditions, using greenhouse cultivation facilities to produce potted flowers is the most economical and reasonable planting method at this stage.

(1) Types of greenhouses At present, managers must be free to work in greenhouses for potted flower production. The most commonly used greenhouses with good performance have the following two specifications:

1. The arched shed is 30m long, 6m wide and 2.2m high, with a culture area of180m2 and an arched tube spacing of 60cm. The material can be galvanized pipe or welded round steel.

2. The arched low shed is 30m long, 2m wide, 1.5 ~ 1.8m high, and the distance between arched pipes is 40 ~ 50cm. Suitable for the propagation of flower seedlings, galvanized pipes are used as materials.

In recent years, with the continuous expansion of potted flower planting scale, there are not only single-span greenhouses, but also double-span and multi-span greenhouses. Its coverage area is1000 ~ 3000m2 (see plate 2). Jiangsu Changshu Kaicheng Greenhouse Manufacturing Co., Ltd. also produces double-layer plastic greenhouses.

(II) Greenhouse Structure There are three kinds of plastic greenhouses commonly used: bamboo or bamboo structure greenhouses, cement structure greenhouses and assembled galvanized steel pipe greenhouses.

1. Bamboo and plastic greenhouses are widely used in Northeast China, North China, Northwest China and Huanghuai area. The shed is 4 ~ 5m wide, 1.8 ~ 2.0m high and 30 ~ 50m long. No columns are set up in the shed. Its advantage is low investment cost. The disadvantage is that the fastness is poor and it is easily damaged by wind and snow.

2. Reinforced concrete greenhouses are generally 6m wide, 2.5m high, with an arch distance of 1m and a length of 30 ~ 50m. It's strong, but it has more shading surfaces.

3. The width of the assembled galvanized steel pipe shed can be 2.5 ~10m, the shed height is 2 ~ 3m, the shed length is10 ~ 60m, and the arch spacing is 50 ~ 65cm. The advantages are convenient and firm disassembly.

(III) Application of Grid Covering Film In the application of greenhouse covering film, with the rapid development of science and technology, there are more and more products with better performance. At present, the most commonly used greenhouse films are as follows:

1.PVC scaffolding formwork has the advantages of good light transmission, strong dust absorption, good heat insulation at night, high temperature and sunlight resistance, durability and easy pasting. But the low temperature resistance is poor.

2. The advantages of polyethylene (PE) shed mould are strong light transmittance, difficult dust absorption and good low temperature resistance. But the high temperature resistance is poor, and the heat preservation at night is slightly poor. The film width can reach 10 meter.

3. The advantages of ethylene-vinyl acetate (EVA) shed mould are good light transmittance, low temperature resistance, aging resistance and good mechanical strength.

(4) Bad environment in the shed According to the greenhouse covered with plastic film, the temperature, light and humidity in the shed are quite different from those in the open field. At the same time, there are obvious differences in temperature, light and humidity in different parts of the shed.

1. temperature, the temperature in the shed is affected by the film quality and natural temperature, and the daily temperature difference and seasonal temperature difference are very obvious. Generally, the temperature near the roof is the highest during the day, near the ground at night, and the temperature on both sides of the greenhouse is lower than the middle. The temperature in the shed can be adjusted by proper ventilation and covering with grass curtains.

2. In terms of light, the light intensity in the shed is not only affected by the light transmittance of the film and the natural light intensity. But also related to the orientation and structure of the greenhouse, and the difference is very obvious. The greenhouse extends from north to south, with strong light on the east side in the morning and strong light on the west side in the afternoon. The light condition of bamboo shed is obviously worse than that of steel pipe structure. The light transmittance of a single greenhouse is better than that of multiple greenhouses. The control of light is not only adjusted by shading net, but also the position of potted flowers should be changed appropriately when they are cultivated, which is beneficial to the orderly growth of stems and leaves.

3. Humidity: The air humidity in the greenhouse increases or decreases due to the changes of greenhouse temperature and weather. Often adjusted by ventilation and shading. Soil moisture is mainly determined by irrigation. When potted flowers, it is necessary to avoid high temperature and high humidity during the day and freezing injury at night.