How to improve the light conditions in the greenhouse?

(1) Timely uncovering of straw thatch, to extend the time of light.

Generally, as long as the sun is visible, you have to pull back the straw. Cover the straw before and after sunset. To try to extend the light time of cucumber, improve the utilization of light energy. In case of rainy, snowy or cold weather, we should also pull open and cover the straw thatch at the right time, generally can be delayed for about half an hour than the sunny day to pull thatch, and never allowed not to pull open the straw thatch.

Possibly some people are worried that when the weather is cold, pulling thatch will cause the indoor temperature to drop. It has been proved that as long as the sun is out, after pulling thatch, the temperature will be increased because of the light, and it is cloudy, as long as it is not too early to pull thatch, the temperature will be increased because of the absorption of a large amount of diffused light. Even if there is a short period of cooling after pulling thatch, it is much better than not pulling thatch, or pulling thatch too late. Because the cucumber leaves as long as the light, even in 2 ~ 5 ℃ low temperature conditions, can also photosynthesize, just lower efficiency, the production of organic nutrients less. If you do not pull straw thatch, cucumber plants in a dark environment, only respiration, consumption of organic nutrients. The longer the dark environment lasts, the more organic nutrients consumed, the more unfavorable to the growth and development of cucumbers. Such a long-term operation, can only be low yield, poor quality, low efficiency, and even cause melon seedling death.

After unveiling thatch, it is necessary to wipe the film in a timely manner to remove the dust and grass clippings on the film, to maintain the transparency of the light film, with good light transmission, to ensure good light conditions indoors.

(2) Hanging reflective film.

The back of the greenhouse light is weak, should be in the greenhouse back wall and the back of the slope surface of the inner side of the reflective film, improve the back of the light conditions, improve photosynthetic efficiency. Practice has proved that the greenhouse after hanging reflective film, the back of the light intensity can be enhanced by more than 20%, so that the back of the crop yield increase of more than 10%.

(3) the implementation of north-south rows, wide and narrow rows planting.

Winter sun height angle is low, between plants, mutual shade heavy, such as the implementation of the east-west row planting, the south row of shade north row, a row of shade, a serious deterioration of light conditions. North and south rows planting, rows and rows, see the light evenly, wide rows and can significantly improve the light conditions between the cucumber plants, enhance photosynthetic intensity, and facilitate direct sunlight on the ground between rows, improve soil temperature, promote root development, improve root activity, to promote the root of strong seedling, and promote the growth of the above ground part of the effect.

Practice shows that effectively raising the soil temperature and promoting the development of the crop's root system is an extremely important technical measure for the success of overwintering cultivation.

(4) Adjust the planting structure and density.

①Strictly control the height of the melon seedling, keep the south low north high, layout uniform group structure. The overall height of the indoor group should be limited to 3/5 of the height of the greenhouse, and it is best to control the height of the plant between 1.5 and 1.7 meters, so as to avoid a high shelf surface, deteriorating lighting conditions, reducing photosynthetic efficiency.

② Appropriately reduce the planting density of the greenhouse north, from south to north, the planting density of each row should be gradually reduced. Planting cucumbers, the southern plant spacing of about 20 cm, the central plant spacing of about 25 cm, the northern plant spacing of about 28 cm, the northernmost 2 to 3 plants, the plant spacing can be expanded to 30 cm or so, try to achieve groups of individual plants between the light uniformity.

(5) Improve the photosynthetic efficiency of the cucumber plant itself.

①Select varieties with high photosynthetic efficiency that are resistant to low light, or more resistant to low light.

②Spray the plants with Tenda 2116, Konkai, brassinolide, photosynthesis micro-fertilizer, etc., to improve the photosynthetic efficiency of cucumber leaves.

(6) artificial supplemental light.

Greenhouse cultivation, if the sunshine time is too short, should be artificial supplemental light. Can be planted in the planting belt north-south span of 1/2 to 1/3, 3 to 4 meters between each phase, about 2 meters from the ground, hanging a 40 to 60 watt energy-saving lamps or incandescent lamps. Cover thatch after the light to 22:00 or so can be.