The growth spectrum required for plant growth

The sensitivity of plants to the spectrum is different from that of the human eye. The most sensitive spectrum of the human eye is 555nm, between yellow-green light. Poor sensitivity to blue and red areas. Plants, on the other hand, are most sensitive to red light and less sensitive to green light, but the difference in sensitivity is not as great as the human eye. The maximum sensitive region of plants to the spectrum is 400-700nm. This region of the spectrum is often referred to as the effective energy region of photosynthesis. About 45% of the energy of sunlight is in this part of the spectrum. Therefore, if an artificial light source is used to supplement the amount of light, the spectral distribution of the light source should also be close to this range.

The energy of the photons emitted by the light source varies according to the wavelength. For example, the energy of 400nm (blue light) is 1.75 times that of 700nm (red light). But for photosynthesis, both wavelengths work the same way. The excess energy in the blue spectrum that cannot be used for photosynthesis is converted to heat. In other words, the rate of plant photosynthesis is determined by the number of photons that can be absorbed by the plant in 400-700nm, and has nothing to do with the number of photons sent out by each spectrum. But the common sense is that the color of light affects the rate of photosynthesis. Plants differ in their sensitivity to all spectra. The reason for this is the special absorption of pigments in leaves. Of these, chlorophyll is the best known. But chlorophyll is not the only pigment useful for photosynthesis. Other pigments also participate in photosynthesis, so the efficiency of photosynthesis cannot only consider the absorption spectrum of chlorophyll.

Weizhao industry plant growth lamp planting effect

Differences in photosynthetic pathways were also unrelated to color. Light energy is absorbed by chlorophyll and carotene in leaves. Energy is converted from two photosynthetic systems that fix water and carbon dioxide to glucose and oxygen. This process uses the entire spectrum of visible light, so the effect of different colors on photosynthesis is almost the same.

Some researchers believe that the orange part of the light has the greatest photosynthetic capacity. But this does not mean that plants should be grown in such monochromatic light sources. Plants should receive a balanced light source for their morphological development and leaf color.

Blue light source (400-500nm) is very important for plant differentiation and stomatal regulation. If there is not enough blue light and the proportion of far red light is too high, the stem will grow excessively and the leaves will be yellowing easily. The ratio between the energy of the red light spectrum (655-665nm) and the energy of the far red light spectrum (725-735nm) is between 1.0 and 1.2, and the development of plants will be positive growth. But each plant has a different sensitivity to these spectral ratios.

High-pressure sodium lamps are often used as artificial light sources in greenhouses. Taking the Philips Master SON-TPIA lamp source as an example, it has the highest energy in the orange-red spectral region. However, the energy of far infrared light is not high, so the energy ratio of red light/far red light is greater than 2.0. But because the greenhouse still has natural sunlight, it doesn't shorten the plants. (This light source may have an impact if used in the growth chamber.)

In natural sunlight, blue light accounts for 20% of the energy. For artificial light sources, such a high ratio is not required. For normally developing plants, most plants only need 6% of blue light energy in the 400-700nm range. In natural sunlight, there is enough blue light energy. Therefore, artificial light sources do not need to add more blue light spectrum. However, when natural light source is insufficient (such as winter), artificial light source needs to increase blue light energy, otherwise blue light source will become a limiting factor for plant growth. But if you don't use the light source improvement method, there are still other ways to remedy this light source shortage problem. Such as temperature regulation or the application of growth hormones.

Shenzhen Feili Rui Technology Co., Ltd. is a company specializing in the development and production of plant lights in our country, engaged in the development and production of plant growth lights sales for more than 10 years, products have nearly 10 years of overseas export experience and qualification. As an important supplier of plant growth lamps in China, our products have also been supplied to Europe and the United States for a long time, including tissue culture plant lamps, industrial hemp plant lamps, modern three-dimensional farm plant lighting lamps and system applications. We have a complete set of perfect and mature plant spectral technology and plant lighting application scheme.