In the past ten years, the area of facility horticulture in my country has developed rapidly, and the light environment control lighting technology for plant growth has attracted attention. Facility horticulture lighting technology is mainly used in two aspects: first, as supplementary lighting for plant photosynthesis when the amount of sunshine is small or short, and second, as inducing lighting for plant photoperiod and light morphology.
1. Research on LED grow light as supplementary lighting for plant photosynthesis
Traditional artificial light sources generate too much heat. If LED supplementary lighting and hydroponic systems are used, air can be recycled, excess heat and water can be removed, and electrical energy can be efficiently converted into effective photosynthetic radiation, and finally into Plant matter. Studies have shown that the use of LED lighting can increase the growth rate and photosynthetic rate of lettuce by more than 20%, and it is feasible to use LEDs in plant factories.
Studies have found that, compared with fluorescent lamps, mixed-wavelength LED light sources can significantly promote the growth and development of spinach, radish and lettuce, and improve morphological indicators; it can maximize the bioaccumulation of sugar beets and the most significant accumulation of betanin in hair roots, and produce them in hair roots. The highest sugar and starch accumulation.
Compared with the metal halide lamp, the pepper and perilla plants grown under the wavelength LED have significant changes in the anatomical morphology of their stems and leaves, and as the optical density increases, the photosynthetic rate of the plants increases. LEDs plant light with multiple wavelengths can increase the number of stomata in marigold and sage plants.
2. LED grow light as the induced lighting for plant photoperiod and light morphology
The specific wavelength of the LED lights grow can affect the flowering time, quality and duration of the flowering period of the plant. LEDs of certain wavelengths can increase the number of flower buds and flowering of plants; LEDs of certain wavelengths can reduce the flower formation response, regulate the length of the stalk and the flowering period, and facilitate the production and marketing of cut flowers. It can be seen that the flowering and subsequent growth of plants can be regulated by LED regulation.
3. Research on LED grow light application in aerospace ecological life support system
Establish a controlled ecological life support system (Controlled Ecological Life Support
System, CELSS) is the fundamental way to solve the problem of long-term manned aerospace life support. The cultivation of higher plants is an important element of CELSS, and one of the keys is light.
Based on the special requirements of the space environment, the light source used in the cultivation of higher space plants must have high luminous efficiency, output light waves suitable for plant photosynthesis and morphogenesis, small size, light weight, long life, high safety and reliability records and no environment Pollution and other characteristics. Compared with other light sources such as cool white fluorescent lamps, high-pressure sodium lamps and metal halide lamps, LEDs lighting are more effective in converting light energy into photosynthetically effective radiation; in addition, it has the characteristics of long life, small size, light weight and solid state, so In recent years, it has received much attention in ground and space plant cultivation. Studies have shown that LED lighting systems can provide lighting with uniform spectral energy distribution, and the efficiency of converting electrical energy into light required by plants is more than 520 times that of metal halide lamps.