Plant lighting refers to the use of LED lights to promote plant growth. Plant lighting generally uses LED plant growth lamps, which are artificial light sources that use LEDs as light bodies to meet the lighting conditions required for plant photosynthesis. Light not only supplies the energy required for plant growth through photosynthesis, but is also an important regulator of plant growth and development. Supplementing or irradiating plants with artificial light can promote plant growth, increase yield, improve product shape, color, enhance functional components, etc., and reduce the occurrence of pests and diseases. The spectrum of plant lighting is relatively complex and diverse. Different plants have different growth cycles and even in different growth environments, and the required spectra are quite different. In order to meet these differentiated needs, there are currently several solutions in the industry:
1. A variety of monochromatic light combination schemes, mainly with the most effective peaks of 450nm and 660nm for plant photosynthesis and the 730nm band for plant flowering induction, plus 525nm green light and lower than 380nm The most suitable spectrum is combined according to the different needs of plants.
2. The full-spectrum solution realizes the full coverage of the spectrum required by plants. This type of spectrum may not be the most efficient, but it is suitable for all plants, and the cost is much lower than that of the monochromatic light combination solution.
3. Based on full-spectrum white light, plus a combination of 660nm red light to improve the effectiveness of the spectrum. This scheme is more economical and practical. Monochromatic light LED plant growth lights are not suitable for the growth of any plant, so the advantages of full-spectrum LEDs are highlighted. The full spectrum must first achieve full coverage of the full spectrum of visible light (400-700nm), and in addition to increase the blue-green light (470-510nm). ), dark red (660-700nm) two-band performance. Use ordinary blue LED or ultraviolet LED chip with phosphor to achieve "full" spectrum, and its photosynthetic efficiency has its own level. Most manufacturers of plant lighting white LED packaging devices use Bluechip+ phosphors to achieve full spectrum. In addition to the packaging mode of monochromatic light and blue light or ultraviolet chip plus phosphor to realize white light, plant lighting packaging devices also have a mode of composite packaging using two or more wavelength chips, such as red ten blue/ultraviolet, RGB, RGBW . This packaging mode has great advantages in dimming. From the perspective of application fields, plant lighting fixtures are mainly used in greenhouse supplementary light, full artificial light plant factories, plant tissue culture, field supplementary light, home vegetable and flower planting, and laboratory research. 1. In solar greenhouses and multi-span greenhouses, the proportion of supplementary light using artificial light is still low, and metal halide lamps and high-pressure sodium lamps are the main ones. The penetration rate of LED plant lighting systems is low, but the growth rate increases with the cost. The decline began to accelerate. The main reason is that users have long-term experience in using metal halide lamps and high-pressure sodium lamps, and the use of metal halide lamps and high-pressure sodium lamps can also provide about 6% of greenhouse gas consumption while avoiding burning plants. 8% heat energy. However, the LED plant lighting system did not provide specific and effective instructions and data support, which delayed its application in sunlight and multi-span greenhouses. At present, it is still dominated by small-scale demonstration applications. Since LED is a cold light source, it can be relatively close to the plant crown and has a small temperature effect. In sunlight and multi-span greenhouses, the application of LED plant lighting is more inter-plant lighting.
2. Field application. The penetration and application of plant lighting in facility agriculture has progressed relatively slowly, while the application of LED plant lighting systems (photoperiod regulation) for outdoor long-day crops (such as dragon fruit) with high economic value has achieved rapid development. 3. Plant factory. The fastest and most widely used plant lighting system is the full artificial light plant factory, which is divided into centralized multi-layer and distributed movable plant factories according to categories. The development of all artificial light plant factories in China is very rapid. The investment subjects of centralized multi-layer fully artificial light plant factories are not traditional agricultural companies, but more companies engaged in semiconductors and consumer electronics. In distributed and mobile plant factories, shipping containers (new or second-hand containers) are still used as the standard carrier. Most of the plant lighting systems in artificial plant factories use linear or flat-panel array lighting systems, and the number of planting varieties continues to expand. LED light sources with various experimental light formulas have begun to be widely used and widely used. The products on the market are mainly green leafy vegetables. 4 . Household planting. LED can be used in household plant table lamps, household plant planting racks, household vegetable growing machines, etc.
5. Cultivation of medicinal plants. The cultivation of medicinal plants such as clematis, Dendrobium candidum, etc. The products in these markets have higher economic value, and it is an industry with more applications in plant lighting at present. 6. Flowering lights. As an essential tool for adjusting the flowering time of flowers in the flower gardening industry, the earliest flowering lamps were incandescent lamps, followed by energy-saving fluorescent lamps. With the progress of LED industrialization, more LED flowering lamps have gradually replaced traditional lamps. Plant Tissue Culture. The traditional light source for tissue culture is mainly white fluorescent lamp, which has low light efficiency and high heat generation. LEDs are more suitable for efficient, controllable and compact plant tissue culture due to their remarkable features such as low power consumption, low heat generation and long life. At present, white LED lamps are gradually replacing white fluorescent lamps.