In the winter and spring season, the light conditions in plastic greenhouses directly affect the growth, yield, and quality of greenhouse vegetables. There are mainly five measures to improve lighting conditions in greenhouses.

The first is to improve the structure of the greenhouse. One is building materials. The best conditions to use the galvanized steel canopy, Shouguang string-style greenhouses, shed 8 with galvanized iron wire tension, not only saving building materials, but also reduce the shading, it is worth promoting. It is best to use a non-drop film for the film, and a polyethylene film for the common film. The whitening of building materials and walls can increase the reflected light and extend the service life; appropriately increasing the height of the greenhouse can also improve the lighting conditions in the shed. The second is the orientation of the greenhouse and the angle of the greenhouse. It should be adjusted according to the greenhouse use time, production purpose and crop light conditions. In plastic greenhouses, which are mainly cultivated in the spring and autumn, the angle of the greenhouses can be smaller, and the greenhouses can be laid flat so that the transmitted light is evenly distributed and evenly distributed. In winter, the greenhouses are required to have a larger angle of the greenhouse and the arches are arched to facilitate daylighting. .

The second is a reasonable mix of planting. When planting different varieties of vegetables in plastic greenhouses, they should be rationally planted in accordance with the principles of North-South High. When sowing seeds, the seeds are moved in the same direction. When transplanting, the cotyledons are arranged in parallel, and the specifications are strictly regulated so that the plants grow neatly and the shading between the plants is reduced as much as possible. The east and the west were planted in the east and the west, and the north and the south were used in the winter and spring to make the plants evenly distributed. In addition, the strengthening of cultivation and management is also conducive to improving lighting conditions in the shed.

The third is to keep the film clean. Water droplets and dust on the shed film have a great influence on the lighting conditions in the shed. The water droplets and dust on the shed film should be cleaned and cleaned frequently, and the snow should be promptly removed after snow, in order to increase the transparency and the amount of light. Outside the greenhouse, covered with warm materials such as grass rakes, etc., under the premise of not significantly affecting the temperature within the shed, appropriate early cover to ensure that the lighting area, extend the lighting time; sheds in the greenhouse after the release of humidity for half an hour, can Decrease the surface of water droplets, which can also increase the light transmittance.

The fourth is to do artificial light. In the winter season or in a sun-defying plastic greenhouse, artificial fill light is particularly important. Specific requirements and practices are: (1) Fill light intensity. Artificial fill light requires greater light intensity. (2) Light source. Studies have shown that crops have the strongest absorption of red light and blue-violet light, so it is better to use fluorescent lights, high pressure mercury lamps, and arc xenon lamps. (3) fill light time. The winter fill light should be carried out after sunrise. Normally, it will take 2 hours to 3 hours per day. After the light intensity in the shed increases, it will stop and the rainy weather will fill the light all day.

The fifth is to promote the use of aluminum film reflective screen. The use of polyester aluminized film spliced ​​into 2 meters wide, 3 meters long reflective screen, hanging in the plastic post after the upper end of the column, hanging down to the ground. In this way, the ground can be increased by 40% to 43%, the greenhouse temperature can be increased by 3°C-4°C, and the ground temperature can be increased by 1.8°C-2.9°C. The laying of silver ash film or aluminum foil on the ground can also increase the light intensity of the plants so that the vegetables and vegetables can be well colored and prevent the premature decay of the lower leaves.

COVID-19 Coronavirus Rapid Test Kit

Anesthesia Medical Co., Ltd. , https://www.honestymed.com