How Important are green led grow lights to affect plant growth？
The effect that green LED grow lights have on plant growth has been debated for years, with both camps convinced of the correctness of their position. While it is true that plants reflect more green light than any other color of the spectrum, and absorb less of it than any other color, it’s also true that only a very small percentage of that green light actually gets reflected away from a plant. The truth is that most of the green light effect generated by lamps is actually useful for the photosynthesis process that takes place in plants.
This is a subject which thus far has not been widely researched or studied, so it cannot be stated positively just how useful green LED lights are for plant growth. However, there are some facts known about green lamp light and its impact on plants, and that’s what will be discussed in this article. You’ll have sufficient information to at least have an educated guess about the efficacy of green light in a grow room for plant growth.
Usefulness of green grow lights
Several different lights are often used to help manage various aspects of a plant’s growth, for instance, its potency or its taste. Green grow lights have an altogether different impact on plants, however, and it primarily involves checking plants for infestations or any kind of damage that might have occurred during the dark cycle. Since the green light wavelength imitates shade or moonlight, they do not disrupt a plant’s night cycle.
It has also been discovered that green light for plants works well in tandem with far-red light, and that can increase the effectiveness of the far-red light. The practical benefits of green plant light are heavily associated with using the green light to check on plants during their grow cycle. Without any kind of interference to the grow cycle, green light can be used to assess plant health, and steps can be taken if, for instance, a pest invasion were to be discovered.
There may be other benefits delivered by the wavelength of green light as well. It appears that green light is better at penetrating a canopy than any other color in the visible spectrum. This can promote the growth of more lushness on lower leaves of a plant, and the potential to achieve a greater yield from each plant. In controlled amounts and when coupled with other colors of light, it appears that green light can contribute to growing stronger, healthier plants.
Positive effect on photosynthesis
The process of photosynthesis is driven by photosynthetically active radiation (PAR), and green light is included in the PAR range. That means it can definitely drive photosynthesis, albeit not as effectively as red or blue light. The curious thing is that when green light accompanies the red or blue light, studies have shown conclusively that plants have a higher photosynthetic rate than they have when it is just red and blue light alone.
This same study also demonstrated that green light has the effect of increasing the number of genes involved with photosynthesis, and significantly lowers the negative impact of prolonged exposure to light. Since plants grown indoors will almost always be exposed to light for more hours than those grown outside, that extra exposure could harm a plant’s productivity. Green light can alleviate those negative effects and reduce any harm that might come from prolonged exposure to indoor lighting.
Given the fact that green light has the capability of lowering stress on plants being grown indoors, it can be very useful in keeping plants healthy and strong. A number of additional studies have found that green light can have a very beneficial impact on photosynthesis, especially a study conducted on the growth of sunflower leaves.
Increasing the height and mass of plants
Plant mass and height will generally be increased by having greater photosynthetic activity, and a number of studies have shown that green light increases photosynthetic activity. One study in particular that was conducted on flowering plants proved that green light exposure caused seedlings to grow faster and taller. Even more important, that same study showed that the plants had a higher yield when exposed to green light regularly.
A study conducted on the growth of tomatoes indicated that including green light in the spectrum of light the plants were exposed to increased the mass of the plants, as well as the stem length, the total leaf area, and the overall yield of the plants. These studies show conclusively that plants exposed to green light will generally increase in mass and height, in addition to having a higher yield.
Leaf penetration ability
The quality of a beam of light is what determines its ability to penetrate through the top layers of leaves, so it can reach leaves at the lower portion of the plant. Anyone involved with growing plants indoors knows that having good leaf penetration will increase the yield of a plant, and that’s why it is considered a very desirable thing.
If light is unable to reach the lower leaves on a plant, the total level of photosynthesis will decrease. That’s why light manufacturers have experimented for quite a few years with ideas that will increase leaf penetration, even modifying the design of grow lights to achieve the desired result. Eventually, some studies found out that green light is better than any other colored light in the spectrum at increasing leaf penetration.
That of course, makes green light extremely valuable to indoor growers, because the bottom line is that green light can help to increase yield of plants grown indoors. By adding green light into the spectrum of grow lights used, a grower can anticipate an increased level of photosynthesis, and ultimately, an increased yield.
All growers understand how critical it is to monitor plant health and growth during their grow cycles, because any serious issues can be identified early on, and steps can be taken to resolve any issues. However, many of today’s LED grow lights emit a light that shines so brightly, it tends to obscure visibility and makes it difficult to actually check on the health of plants. Most of these LED lights are comprised of red and blue lights, and the light they emit becomes purple.
This purple light decreases visibility and makes it much harder to monitor the health of plants being grown. Nowadays, many growers avoid buying these kinds of LED lights for that very reason, because they know how important it is to be able to check the health of plants at various stages of the grow cycle. The obvious solution was to add green light to the spectrum of colors used in these LED lights, and that’s what manufacturers have done.
Green light improves visibility significantly, thereby making it far easier to monitor plant growth and spot any problems in the early stages. This means that in addition to impacting height, mass, and yield, green light can also make it easier for growers to see any problems that might be affecting their plants, so they can be remediated.
How much green light do plants need？
So, from all the information above, it should be fairly apparent that plants will prosper better if they receive a certain amount of green light in the spectrum they’re exposed to. But how much green light is called for? It is known that not as much green light is needed as red and blue, and in fact, too much green light can cause harm to a plant.
Too much green light can inhibit or slow down the natural processes triggered by blue light. That means an excessive amount of green light can actually decrease photosynthesis and correspondingly cause a lower yield to be harvested. It is known that too much green light can have a negative impact on the level of THC in cannabis plants, and that will lower the marketability of the cannabis plants.
Excessive green light can also trigger symptoms in plants that mimic shade avoidance syndrome (SAS), which will also lower the yield a plant is capable of. So, it becomes necessary to add a very specific amount of green light to the spectrum of color that any plant is exposed to, so as to gain the benefits of green light, without inducing any of the negative effects.
For this reason, many of today’s grow lamps incorporate only moderate amounts of green light into their spectrums, and this approach has proven to be quite successful. The cannabis industry for instance, has made very effective use of grow lights having this moderate green light percentage, and has found the appropriate balance between red, blue, and green light.
The key seems to be to choose a grow light that emits enough red and blue light to counter any negative effects that green light might produce, but to avoid choosing a grow light that emits no green light whatsoever. Adopting this approach should provide the very best plant growth for your indoor crop, and the most productive yield.