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[Prawn Connery]

The opinion paper says, "The majority of green light is useful in photosynthesis". Then in the very next sentence it says, "Green light is the least efficiently used color of light in the visible spectrum". -- Meaning, the paper is saying the exact opposite.

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Plant chlorophyll has little use for green wavelength light. Sure it may use a little, but it uses it inefficiently.

Individual wavelengths carry more or less energy - blue carries more energy than green, which carries more energy than red.

Plants absorb and reflect different wavelengths at different rates - green is generally absorbed less than blue and red.

Photosynthetic efficiency is how efficiently the plant uses each wavelength that is absorbed - green may be less absorbed, but it tends to produce a stronger photosynthetic reaction than blue light.

So there are three basic factors that determine rate of photosynthesis - you cannot look at each one in isolation.

A chocolate bar has more sugar than a celery stick. Therefore you need to eat a lot more celery to get the same amount of energy. Green doesn't need to be absorbed as efficiently, because once it is absorbed, it is used more efficiently by the plant.

 

[Serva]

The main reason we give plants light is for energy to grow, different qualities of light produce different potency (by a small margin typically) and more or less intense turpenes. My weed is better than it's ever been for the past year and a half under LED compared to when I grew under HID. Smell, taste, potency, yield. From what I understand my LED's have less green than HID. It's also commonly agreed upon that green is the least desirable of the color spectrum to grow under.

Read about the biology of a plant... like I said, my mother tounge is german, and my vocabulary is limited. Just check out for example: phytochroms, anthocyans, cryptochroms, and so on

A plant has soo many light sensitive receptors! Every receptor is important for the health of a plant. And a sunlight bud is always what I prefer. Indoor growing is just necessar for me, because of enviroment conditions I would need to battle outside.

 

[see4]

Individual wavelengths carry more or less energy - blue carries more energy than green, which carries more energy than red.

Plants absorb and reflect different wavelengths at different rates - green is generally absorbed less than blue and red.

Photosynthetic efficiency is how efficiently the plant uses each wavelength that is absorbed - green may be less absorbed, but it tends to produce a stronger photosynthetic reaction than blue light.

So there are three basic factors that determine rate of photosynthesis - you cannot look at each one in isolation.

A chocolate bar has more sugar than a celery stick. Therefore you need to eat a lot more celery to get the same amount of energy. Green doesn't need to be absorbed as efficiently, because once it is absorbed, it is used more efficiently by the plant.

Ok. I can understand that.

That MSU articles goes on to say..

The utility of green light in plant growth applications has been demonstrated by multiple researchers at different universities and research institutes. For example, in an experiment performed at Michigan State University, partly substituting red light for green light (resulting in 25 to 50 percent green light) reduced extension growth of seedlings, making leaves slightly smaller and stems shorter. However, plant fresh weights were similar. Under higher proportions of green, some experiments indicate that green light can actually promote extension growth, somewhat similar to the effects of far-red radiation. Therefore, the effects of green depend on its intensity, the crop and what other wavebands and intensities of light are delivered.​

I interpret that as, you need a ton of green light for a plant to grow the same as if giving it the far red and blue spectrums we are used to giving it. Or rather much more intense green light.

 

[see4]

my mother tounge is german

ahh, that explains it.

 

[Stephenj37826]

https://www.ncbi.nlm.nih.gov/m/pubmed/19246458/

 

[ANC]

But the fish babys will have adapted better than the parental generation, no?

No, natural selection will kill of phenotypes that can not live at the given parameters.

I love me some Rammstein. I don't speak German, but I understand and can read it.

 

[Prawn Connery]

The main reason we give plants light is for energy to grow, different qualities of light produce different potency (by a small margin typically) and more or less intense turpenes. My weed is better than it's ever been for the past year and a half under LED compared to when I grew under HID. Smell, taste, potency, yield. From what I understand my LED's have less green than HID. It's also commonly agreed upon that green is the least desirable of the color spectrum to grow under.

Among other things, different spectra are responsible for different hormone production and growth response - which is why blue light can control stretch and red light can improve flowering. LEDs have a lot more green than HPS - if you define "green" as around 550nm. LEDs are simply more efficient.

Green light definitely has its place in providing photosynthetic efficiency for shade leaves and flowers below the canopy line.

You might also be a better grower now than when you were growing with HIDs

 

[coreywebster]

There are studies which say that plants use green light partly for shade avoidance, because green light passes though canopies it signals the plants are too close together and kicks in the shade avoidance, but I believe it has to do with the ratio of RGB and this happens when most other light has been absorbed or blocked by upper canopy, leaving a high green ratio.
Cant find the article to cite I'm afraid. I think our understanding of light and how its used by plants and its different functions is comparable to 1800s medicine. So it exciting to think about what we will find out in the future and how we will apply that in our gardens.

 

[Prawn Connery]

I interpret that as, you need a ton of green light for a plant to grow the same as if giving it the far red and blue spectrums we are used to giving it. Or rather much more intense green light.

Not really, as green light penetrates more than red and blue. Which means, if most of the red and blue is absorbed by the canopy, then the shade leaves are relying much more on the green light that penetrates.

And that may well partly explain the conundrum of why leaves reflect more green light: because it is reflected down, side-ways and inwards - into other areas of the canopy - as well as up and away from the plant.

Therefore, the plant is actually directing light back towards itself that can be used lower down the canopy.

 

[Prawn Connery]

All I'm saying is, Nature is very smart. Smarter than us! If sunlight contains green light, then you can guarantee plants have found a way to use it. And generally in the most efficient way possible.

 

[see4]

Not really, as green light penetrates more than red and blue. Which means, if most of the red and blue is absorbed by the canopy, then the shade leaves are relying much more on the green light that penetrates.

And that may well partly explain the conundrum of why leaves reflect more green light: because it is reflected down, side-ways and inwards - into other areas of the canopy - as well as up and away from the plant.

Therefore, the plant is actually directing light back towards itself that can be used lower down the canopy.

Yea, I'm starting to get the rationale behind green wavelength... reading through Stephen's citation..

So why aren't we producing diodes and bulbs that produce more of this green light? I mean that research paper Stephen cited was from 10+ years ago.

Also, is that what they mean when they say "light penetration", that the light penetrates the canopy of leaves, or rather that it penetrates deeper into the leaves cell body.

 

[ANC]

Incandescents have had their day. The game is over.
1 100W Samsung F Gen3 strip puts out more than 10 times the number of lumens an ordinary 100W incandescent does.

I reckon the reason it is not used more is because it does not add to yield, only plant health

 

[Serva]

No, natural selection will kill of phenotypes that can not live at the given parameters.

I love me some Rammstein. I don't speak German, but I understand and can read it.

I love them! pretty intelligent songs... but they play with the german language, guess it‘s hard to understand everything, they are telling you.

And I can‘t understand your „no“. Only the strongest fishes will live, the ones that have adapted the best. So the parents will give on the adapted genes to the babys, which will be adapted because of this even better. Natur is selecting by killing the weak (or they find a niche), and letting the strong ones evolve, generation by generation.

 

[see4]

Incandescents have had their day. The game is over.
1 100W Samsung F Gen3 strip puts out more than 10 times the number of lumens an ordinary 100W incandescent does.

I reckon the reason it is not used more is because it does not add to yield, only plant health

It's sort of like CPUs. The newest and greatest is legacy crap in 1 year or less.

 

[coreywebster]

I also have a theory that green light has something to do with how well a plant can handle high PPFD without bleaching.
Its only a theory, but it seems from the old mono blurple lights when folk ran high PPFD in a tent they more often had that bleached bud effect more than someone running a mixed spectrum like that of white light running similar PPFDs.
Although I have seen some bleached buds under whites it doesn't seem as common. It just a theory though so don't tear me a new asshole for not having the evidence to back it up.

 

[ANC]

My mother tongue is Afrikaans, which is germanic, so many of the figures of speech translate well or are similar.
Another one of their songs I love is Spieluhr. Hoppe hoppe reiter!!!!!!!

 

[CobKits]

makes sense.
but if the plant is not efficiently using the green light, why give it? from what i understand only 10% of green light is transmitted in through the leaves where the chlorophyll begins to make use of it.

because there is much more to plant physiology than photosynthesis. thats like comparing the utility of oxygen and vitamin B12 in humans

 

[ANC]

Natur is selecting by killing the weak (or they find a niche), and letting the strong ones evolve

Gonna throw a C4 at you, notice how most of what people call evolution, is selecting for a diminished gene pool. Each subsequent evolutionary product has less of the genome information than the previous. If you were to take the latest evolutionary iteration back in time, it would die off some time after as it no longer carries the data in its gene pool to have some member survive adversity.

 

[see4]

After further reading, I've found this..

It’s true that plants appear green because leaves reflect more green light than other visible wavelengths, but typically only around 5 to 10 percent of green light is reflected, and the rest is absorbed (roughly 85 percent) or transmitted (5 to 10 percent) through the leaf. Light transmitted through one leaf is subsequently available to leaves below, so those photons are still potentially useful to plants. In addition, pigments other than chlorophyll absorb green light to make it useful for photosynthesis. Therefore, green photons are essentially as useful to plants for photosynthesis as red and blue photons.
​

Which completely flies in the face of what I've understood in the past.

Still looking for where its shown that red and blue spectrums are transmitted at smaller rates (5-10%) than green spectrums...

 

[Prawn Connery]

Gonna throw a C4 at you, notice how most of what people call evolution, is selecting for a diminished gene pool. Each subsequent evolutionary product has less of the genome information than the previous. If you were to take the latest evolutionary iteration back in time, it would die off some time after as it no longer carries the data in its gene pool to have some member survive adversity.

That's what mutation is for. Mutation drives evolution.