G reenhouse Cultivation Techniques of LED Grow Light
With LED lighting applications gradually expanded, more and more bio-industry noted LED lighting business. In Canada, for example, sales of greenhouse fruits and vegetables more than 1.1 billion US dollars. How to provide effective lighting for the greenhouse is the key to support greenhouse production and increase revenue.
For the production side, even at moderate temperatures, adequate nutrition and water conditions, the greenhouse will be affected due to limited light. McGill University Canadian researchers believe that the current greenhouse supplementary lighting commonly used methods, such as traditional high pressure sodium lamp for plant growth is not the most efficient light sources, thus actively seeking other alternative lighting.
Researchers noted that the light which plant photosynthesis need is at a wavelength of about 400nm to 700nm, especially the blue and the red light region is the closest plant photosynthesis efficiency curve. They think that growers can use LED grow light to combine specific wavelengths of light according to the needs, so as to convert the light to photosynthetically active radiation. Not only can improve plant yield, but also to control invalid wavelength which impact the growth of plants. There is also conducted experiments to test whether LED lights can reduce lighting costs of greenhouse.
Scientists had a test with hydroponic tomato. They had a 120-day test with red and blue LED lights in three ratio according to three kinds of light intensity. They also compared with several other light supplement ways including high pressure sodium hundred percent, one hundred percent red light LED lamps, high pressure sodium lamp with the red LED lights in half, and without any supplements.
The results show that the five kinds of light mode which make the most fruit production are in order,red and blue LED ratio of 5: 1 high light intensity, 5: 1 middle light intensity,5: 1 low light intensity, 19: 1 high light intensity and one hundred percent LED lighting. The effect on plant growth assisted by the LED illumination is more ideal than high pressure sodium lamp. It is also said that the method to improve greenhouse lighting appeared.
On the other hand, the experimental results also show that high illuminance can enhance plant growth and fruit production. 19:1 can produce more plant material, 5:1 can increase fruit production. McGill University researcher pointed out that increasing the number of red LED lights hyperplasia plant material, fruit production is reduced slightly. Therefore, LED grow lights in strengthening greenhouse artificial lighting systems, by the relevant researchers believe is extremely useful method.