Light is an essential energy source for plant growth. As we all know, light regulates photosynthesis, growth and development, morphogenesis and material metabolism of plants. At present, fluorescent lamp, high pressure sodium lamp and incandescent lamp are used to make up for the lack of sunlight in greenhouse and greenhouse planting. The spectral energy distribution of these light sources is designed according to the light demand of human eyes, while the spectrum required for plant growth is different from that of human eyes. But the LED wavelength type is rich, the adjustable room is bigger, suitable for the plant lighting
The effects of different wavelengths of light on plant photosynthesis are different. The wavelengths of light needed for plant photosynthesis are about 400 ~ 720nm. The absorption ratio of chlorophyll and carotenoid is the largest in the light of 400-520nm (blue), so it has the greatest impact on photosynthesis. The effect of 610 ~ 720nm (red) light on Photosynthesis and photoperiod was significant. 520 ~ 610 nm (green) light, pigment absorption rate is very low. Therefore, the plant lamp is generally made into three forms: Red Blue ratio, all blue and all red. Generally, the red light wavelength is 620-630nm or 640-660nm, and the blue light wavelength is 450-460nm or 460-470nm. To provide red and blue wavelengths of light, covering the wavelength range required for photosynthesis. In the visual effect, the combination of red and blue plant light is pink.
The proportion of red and blue light of plant lamp is generally 5:1 ~ 10:1, and the proportion of 7 ~ 9:1 is usually selected.
Through the application test, the wavelength of LED plant lamp is very suitable for the growth, flowering and fruit of plants. General indoor plants and flowers will grow worse and worse with time. The main reason is the lack of light. Through the LED light which is suitable for the spectrum of plants, it can not only promote their growth, but also extend the flowering period and improve the quality of flowers. The application of this high-efficiency light source system to the greenhouse, greenhouse and other facilities of agricultural production can also solve the problem that the lack of sunlight leads to the decline of the taste of vegetables in the greenhouse, such as tomatoes, cucumbers and so on.
