Measures to improve the daylighting rate of vegetable greenhouse

The light conditions in the greenhouse directly affect the growth and development, yield and quality of vegetables. Especially in the overcast, rainy, icy and snowy weather, the light is weak. The lack of light of vegetables in greenhouse is a common problem. Lack of light, not only can not carry out exuberant photosynthesis, transpiration is also reduced, plant growth is weak, affecting the yield and quality of vegetables. Therefore, it is necessary for the production of greenhouse vegetables to take some effective measures to improve the lighting conditions in the greenhouse. The measures are:

Rational layout. When planting different kinds of vegetables in the greenhouse, we should follow the principle of "high in the north and low in the south" to make the plants high and low in order and minimize the phenomenon of mutual shielding. When the same kind of vegetable is transplanted, the seedling size is the same, so that the plant grows neatly and the shading between plants is reduced. At the same time, it is better to plant the border in the north-south direction so that it can accept the sun as much as possible.

Keep the greenhouse film clean. Water droplets, dust and other sundries on the greenhouse film will reduce the light transmittance by about 30%. After using the new film for 2 days, 10 days and 15 days, the light in the greenhouse will be reduced by 14%, 25% and 28%, respectively. Therefore, it is necessary to often clean and wash the dust, dirt and water droplets on the surface of the shed to keep the surface clean so as to increase the transparency of the film.

Reasonably uncover the straw curtain. On the premise of doing a good job of heat preservation, removing the grass curtain and delayed cover curtain in advance can prolong the lighting time and increase the amount of daylighting. Usually open the curtain 0.5-1 hour after the sun comes out, and cover the curtain half an hour before sunset. Especially in rainy and rainy days, the curtain should be opened properly to make full use of the scattered light from the sun.

Choose drip-free film. Several active agents are added to the formulation of the drip-free film, which greatly weakens the affinity between the water molecules and the film, and the water droplets flow into the ground along the film surface without water droplets. The selection of drip-free film buckle shed can increase the light intensity in the shed and increase the temperature of the shed.

Set the reflective screen. The aluminized film reflective screen with a width of 2 meters and a length of 3 meters is hung on the north side of the greenhouse to make it perpendicular to the ground, which can increase the ground light by about 40% and the greenhouse temperature by 3 ℃-4 ℃. In addition, laying silver-gray plastic film on the ground can also increase the light intensity between plants.

Do a good job in finishing the plants. Timely field management such as pruning, branching, binding vines and beating old leaves is conducive to ventilation and light transmission in the shed.

Sunlight is a necessary condition for photosynthesis of green plants. In the season of less light hours and low intensity, collecting more sunlight in the greenhouse plays an important role in improving the yield and quality of vegetables.