What's the principle and Prospect of Plant Growth Lamps ?
After application test, the wavelength of plant lamp is very suitable for plant growth, flowering and fruit. Generally, indoor plants and flowers will grow worse and worse over time. The main reason is the lack of light irradiation. The irradiation of LED lamp suitable for the spectrum required by plants can not only promote their growth, but also prolong the flowering period and improve the quality of flowers; The application of this high-efficiency light source system to agricultural production such as greenhouses, greenhouses and other facilities, on the one hand, can solve the disadvantages of the decline in the taste of greenhouse vegetables such as tomatoes and cucumbers caused by insufficient sunshine, on the other hand, it can also make the winter Greenhouse Eggplant and fruit vegetables listed before and after the Spring Festival, so as to achieve the purpose of Off-season Cultivation.
1. As supplementary lighting, it can enhance the lighting at any time of the day and prolong the effective lighting time.
2. Whether at dusk or night, it can effectively prolong and scientifically control the light required by plants.
3. In greenhouse or plant laboratory, it can completely replace natural light and promote plant growth.
4. Completely solve the situation of relying on natural climate growth in the seedling raising stage, and reasonably arrange the time according to the delivery date of seedlings.
Significance of interior lighting in Greenhouse
What we need to know is that the growth rate of plants depends on the light intensity, that is, the amount of light radiation absorbed by the plant surface, not the number of light sources. Many people ask, what is the significance of greenhouse internal lighting, how to do it, and what kind of light source should be selected?
The significance of greenhouse interior lighting is to extend enough light intensity in a day. It is mainly used to grow vegetables, roses and even chrysanthemum seedlings in late autumn and winter. Greenhouse lighting has a great impact on the growth period and seedling quality. Usually, for tomatoes, light will start after the plant seedlings grow two cotyledons. Continuous light for 12 days can reduce the seedling preparation period of 6-8 days. But more than 24 hours of light is a disorder of plant growth. The most suitable lighting time is 8 hours a day.
In cloudy and low light intensity days, artificial lighting is necessary. At least 8 hours of light should be given to the crops at night, and the time of light should be fixed every day. However, the lack of night rest time will also lead to plant growth disorder and yield reduction.
For tomatoes, the most effective lighting time is from dusk to midnight, 16:00-24:00, or from midnight to 24:00-8:00 in the morning. Such lighting for 8 hours and rest for 8 hours. In practice, we should provide light for plants in the whole growth period, that is, from seedling to colonization. In the final period, we should reduce the light to 6 hours a day or even stop for 2-3 days. If it takes a long time to reach the planting period due to poor light conditions, the light usually lasts for one month.
Under the fixed environmental conditions such as carbon dioxide, water, nutrients, temperature and humidity, the "photosynthetic flux density PPFD" between the light saturation point and light compensation point of a specific plant directly determines the relative growth rate of the plant; Therefore, efficient light source PPFD combination is the key to the production efficiency of plant factory.
Selection of light source
Scientific selection of light source can better grasp the speed and quality of plant growth.
When using artificial light sources, we must choose the natural light that is closest to meeting the conditions of plant photosynthesis.
Measure the photosynthetic light flux density (PPFD) produced by the light source on the plant, master the rate of plant photosynthesis and the efficiency of the light source, and the light amount of photosynthetic effective photons to start plant photosynthesis in the chloroplast: including light reaction and continuous dark reaction.
The light source shall have the following characteristics:
1. Efficient conversion of electric energy into radiant energy
2. Achieve high radiation intensity within the effective range of photosynthesis, especially low infrared radiation (thermal radiation)
3. The radiation spectrum of the bulb meets the physiological requirements of plants, especially in the effective spectral region of photosynthesis.
Among all kinds of artificial light sources with comparative intensity in the effective area of photosynthesis and horizontal radiation, the energy conversion effect of sodium lamp is twice as high as that of mercury lamp. Sodium lamp is the most effective light source affecting plant photosynthesis and correct growth in greenhouse. Tubular sodium lamp can reach 150lm / w high light efficiency radiation, which is the most favorable choice for the growth of various crops. It is added in ceramic arc tube The sodium vapor pressure in can expand the spectrum of blue and red light, which is the high range wavelength pursued.
We recommend plantastar (OSRAM), son-t agro (Philips), Lucalox XO (GE) for high pressure sodium lamps used in horticultural products The difference between them is to increase the 0-40% blue light range and activate the chlorophyll of plants. In order to obtain the highest radiation energy, all sodium lamps are equipped with a reflective layer on the inner side of the lampshade. At present, most domestic factories generally use sodium lamps as street lamps on the spot, and plant sodium lamps are exported, causing a lot of losses to the majority of users.
Light environment is one of the indispensable physical environmental factors for plant growth and development. Controlling plant morphogenesis through light quality regulation is an important technology in the field of protected cultivation.
Effect of spectral range on Plant Physiology:
280nm ~ 315nm had little effect on morphological and physiological processes
The absorption of chlorophyll at 315 nm ~ 420nm is less, which affects the photoperiod effect and prevents stem elongation
The absorption ratio of 420 nm ~ 500 nm (blue) chlorophyll to carotenoid was the largest and had the greatest impact on photosynthesis
The absorption rate of 500 nm ~ 620nm pigment is not high
620nm ~ 750nm (red) chlorophyll absorption rate is "high", which has a significant impact on Photosynthesis and photoperiodic effect
The absorption rate of 750nm ~ 1000nm is low, which stimulates cell elongation and affects flowering and seed germination
>1000nm converted to heat
The wavelength types are abundant, which coincides with the spectral range of plant photosynthesis and photomorphogenesis; The half width of spectral wave is narrow, and pure monochromatic light and composite spectrum can be combined as required,; It can focus light of specific wavelength to irradiate crops evenly; It can not only regulate the flowering and Fruiting of crops, but also control the plant height and plant nutrients; The system has less heat and small occupied space, and can be used in multi-layer cultivation three-dimensional combination system to realize low heat load and miniaturization of production space;
Sunshine is a necessary factor for plant growth in addition to nutrition and water. But every grower knows that sunlight is uncontrollable. Therefore, artificial sunlight is more and more recognized in horticultural cultivation, because artificial sunlight can artificially control the season of plant growth and completely shorten the time of plant growth.
It can be used for the following purposes:
1. As supplementary light, light can be enhanced at any time of the day to always help plants photosynthesis. Especially in the winter months, the effective lighting time can be extended.
Whether at dusk or night, it can effectively prolong and scientifically control the light required by plants without being affected by any environmental change.
2. In greenhouse or plant laboratory, it can completely replace natural light to promote plant growth.
For most growers, plant sodium lamp and metal halide lamp are the best light sources to replace sunshine. Metal halide lamp is rich in blue light, which is suitable for the growth of plant branches and leaves in the early stage. Agricultural sodium lamp is rich in red orange light, which has a positive effect on promoting plant flowering and fruiting.
With the rapid development of protected horticulture area in China, the light environment control and lighting technology for plant growth has attracted much attention. Facility horticultural lighting technology is mainly applied in two aspects:
1、 It can be used as supplementary lighting for plant photosynthesis when there is little sunshine or short sunshine time;
2、 As an induced illumination for plant photoperiod and light morphogenesis.
3、 Main lighting of plant factory