What is the effect of green light?

Author: Lillian Liu   

Many growers believe that green light is useless in the planting process, but it is not. Many people think that green is useless because many plants reflect green. But actually only part of the green is reflected, giving the plant a green appearance. So today we will discuss the role of green light and justify the name of green light.

Green light can be defined as light with a peak wavelength between 500 and 600 nanometers (nm). These green bands fill the gap between blue and red light in the visible spectrum, and when combined with amber light, green produces a full spectrum of "white" light. But you won't find green LED fixtures on the market, and you won't see green LEDs in full spectrum fixtures. While green LEDs are useful for research, they are not practical for commercial cultivation. Due to manufacturing technology limitations, green LEDs lack the electrical efficiency of other color LEDs. White LEDs, on the other hand, can efficiently provide green light and fill the rest of the spectrum. So instead of green LEDs, lighting engineers use "white" LEDs that produce both green and other wavelengths. It's important to note that although some manufacturers refer to green light, they usually refer to the white LED inside the lamp.

Research has repeatedly shown that cannabis plants use green light, which drives photosynthesis and plays other important roles. In the canopy, green light that is not reflected or absorbed by the upper leaves is transmitted, deep into the lower leaves. While leaves do reflect green light - and thus appear green to our eyes - most of the green light is still used. Only 5-10% of the green photons are lost by reflection; the rest are absorbed or transmitted. The transfer of green to the lower canopy also reduces the senescence of the bottom leaves, and their continued health allows them to continue to help with photosynthesis. Under intense white light, green has been shown to drive photosynthesis more efficiently than red light. And the inclusion of 24% of the green light in the blue-red spectrum has been shown to boost lettuce growth. There is no doubt that the green light promotes growth. It is reasonable to assume that cannabis plants use green light more than other crops. Cannabis is an extremely light plant with a dense canopy. Because green light penetrates leaves better than other colors—and because green light drives photosynthesis efficiently in intense white light—green wavelengths lead to larger flower development. Green light also signals plant morphology. It plays an important role in mediating plant responses to blue light and affects leaf growth and early stem elongation.

Through the article we believe you will have a different view on green light. And we hope this also helps you make better decisions about the spectrum.