Analysis of Greenhouse Cultivation Techniques of LED Plant Lights

With the gradual expansion of LED lighting applications, more and more operators are paying attention to LED bio-lighting opportunities. In Canada, for example, the annual sales of greenhouse fruits and vegetables exceeds US$1.1 billion. How to provide effective illumination for greenhouses is the key to supporting greenhouse cultivation and increasing revenue.

With the gradual expansion of LED lighting applications, more and more operators are paying attention to LED bio- lighting opportunities. In Canada, for example, the annual sales of greenhouse fruits and vegetables exceeds US$1.1 billion. How to provide effective illumination for greenhouses is the key to supporting greenhouse cultivation and increasing revenue.

LED replaces traditional high pressure sodium lamp to help plant growth

In terms of yield, even in moderate temperatures, nutrients and sufficient water, greenhouse cultivation will be affected by limited light. Researchers at McGill University in Canada believe that the current way of supplementing light in greenhouse cultivation, such as traditional high-pressure sodium lamps, is not the most effective source of light for plant growth, and is therefore actively seeking alternative illumination.

The researchers pointed out that the light required for photosynthesis in plants, with wavelengths ranging from 400 nm to 700 nm, especially in the blue and red regions, is closest to the efficiency curve of plant photosynthesis. They believe that growers can use LED plant lights to combine specific wavelengths of light as needed to convert light into photosynthetically active radiation. Not only can it increase plant yield, but it also controls wavelengths that are ineffective for plant growth. In addition, relevant experiments were conducted to test whether LED lamps can reduce the lighting cost of greenhouse cultivation.

Red and blue LED5:1 performance of the best red LED to increase plant matter

The scientists used hydroponic cultivation of tomato as the test object. The three red and blue LED lamps were tested for three days according to the three light intensities. They were compared with other light filling methods, including 100% high-pressure sodium lamps and 100% red. Light LED lights, high pressure sodium lamps and red LED lights, and no fill light.

The results showed that the five light modes with the highest fruit yield were red-blue LED ratio 5:1 high light intensity, 5:1 medium light intensity, 5:1 low light intensity, 19:1 high light intensity, and 100% LED illumination. The use of LED lighting to assist plant growth is more effective than high-pressure sodium lamps, and it also indicates an improved lighting method for greenhouse cultivation.

On the other hand, the experimental results also show that high illuminance enhances plant growth and fruit yield. A ratio of 19:1 produces the most plant matter, and a ratio of 5:1 increases fruit yield. Researchers at McGill University pointed out that increasing the number of red LED lights can accumulate plant matter, and fruit production is slightly lower. Therefore, LED plant lights are considered to be a very helpful method for researchers to strengthen the artificial lighting system in greenhouses.