How does the Spectrum of LED Grow Light Affect the Plant Growth?
For indoor planting, lighting is an essential energy source for photosynthesis, and more and more people choose to invest LED plant lighting systems. There are various LED lights like incandescent lamps, fluorescent lamps in the market. But only LED plant lights to have the overwhelming advantages that traditional supplemental lights do not have, and will certainly become the first choice for commercial growing such as vertical farms and greenhouses.
Because the lighting that plants need for photosynthesis is different from the light we use for everyday lighting. Photosynthesis is the process by which plants use the sun's light energy to assimilate carbon dioxide (CO2) and water (H2O) to make organic matter and release oxygen.
First, let’s look at how different spectrums affect the growth of plants.
- 280 ~ 315nm: little effects on morphological and physiological processes;
- 315-400nm: Chlorophyll absorption is low, which affects photoperiodic effect and prevents stem elongation;
- 400-520 nm (blue): the absorption ratio of chlorophyll and carotenoids reaches the largest, which has the greatest effect on photosynthesis.
- 520 ~ 610nm (green): the absorption rate of pigment is not high;
- 610 ~ 720nm (red): the chlorophyll absorption rate is low, which has a significant effect on photosynthesis and the photoperiodic effect
- 720 ~ 1000nm: low absorption rate, stimulate cell elongation, affect flowering and seed germination
- >1000nm: convert into heat.
According to the above data, different wavelengths of light have different effects on plant photosynthesis. The wavelength of light needed for plant photosynthesis is about 400 ~ 720nm. Light at 400 ~ 520nm (blue) and 610 ~ 720nm (red) contributed the most to photosynthesis. At 520 ~ 610nm (green), the rate of absorption by plant pigments is very low.
- Wavelengths of 400 ~ 420nm help to generate anthocyanins and resists the elongation of branches and leaves.
- The wavelength of 450 ~ 460nm improves the growth of stem and leaf, accelerates plant development and regulate stomatal opening.
- At 550nm, it promotes the generation of oxygen and helps tissues store nutrients better.
- The wavelength of 580nm can promote the growth of roots and early germination.
- The wavelength of 650-660nm promotes the overall growth of the plant, especially in the flowering and fruit-bearing period, increasing the growth rate (20 days earlier flowering, 30 days earlier harvest), increasing the number of fruit by 25% to 35%, and reducing the incidence of malformed fruit.
- The low absorption rate at 720 ~ 1000nm stimulates cell elongation and takes influences flowering and seed germination.
Plants must have appropriate light rays to carry out photosynthesis, and the spectrum range is very important for the impact of plant physiology. So only LED light can meet the above conditions because only LED light can emit the spectrum required by plant growth.
LED grow lights are basically featured with red and blue light, covering the wavelength range required for photosynthesis. Visually, the combination of red and blue plant lights is pink.
When using LED plant filling with actual power lower than 50W for indoor growing, the distance from the plants should be between 0.2 ~ 0.8 meters, 50W+ be 0.5 ~ 1.5 meters.
LED grow lights are the best choice for your growing.
- XU HONG