Sativied
Well-Known Member
So you say white leds equals wasting lumen$, but then you add a green led?
Invasion of Red and Blue LEDs: Humble Beginnings
- Thread starter PetFlora
- Start date
Pass it Around
Well-Known Member
A little green is good, the plant will suck that shit up.So you say white leds equals wasting lumen$, but then you add a green led?
Sativied
Well-Known Member
Summer vacation still not over for you... I obviously wasn't asking you to clarify, what the fuck do you know about anything?
Any clue why plants are green? Cause they suck at absorbing that shit up...
Pass it Around
Well-Known Member
I was just regurgitating what that pet flora noob was saying earlier. No reason to be a cunt?Summer vacation still not over for you... I obviously wasn't asking you to clarify, what the fuck do you know about anything?
Some early LED backlights for TVs utilized RGB LEDs, but the designs generally had to include two green LEDs for every red and blue one [...]
Green LED inefficiency stems from a semiconductor physics phenomenon called the charge separation effect. In green LEDs, electrons and electron holes are separated in the quantum-well region of the device. Light is generated when electrons combine with electron holes, but the separation results in fewer such combinations in green LEDs.
http://www.ledsmagazine.com/articles/2011/04/rensselaer-researchers-boost-green-led-efficiency.html
Green Light Drives Leaf Photosynthesis More Efficiently than Red Light in Strong White Light: Revisiting the Enigmatic Question of Why Leaves are Green
http://pcp.oxfordjournals.org/content/50/4/684.Abstract
I just concluded, the title actually says: "CXA3070 Drives Leaf Photosynthesis More Efficiently than Red Light in Strong CXA3070 Light"
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Sativied
Well-Known Member
Well, there's always a good reason to treat a punk like a punk. The advice and comments you crap over this forum are of the same level as mainliner's... only difference is you can spell
Not saying you're wrong about your assessment of pet flora though... it's just a little odd coming from you. Took me months to figure that out, I thought the guy actually knew his shit... but I guess it's even easier for a bullshitter to recognize a bullshitter.
ficklejester
Well-Known Member
+1Well, there's always a good reason to treat a punk like a punk. The advice and comments you crap over this forum are of the same level as mainliner's... only difference is you can spell
Not saying you're wrong about your assessment of pet flora though... it's just a little odd coming from you. Took me months to figure that out, I thought the guy actually knew his shit... but I guess it's even easier for a bullshitter to recognize a bullshitter.
I (and many others I'm sure) respect and trust the information provided by members who make it clear their efforts on RIU are for the benefit of furthering knowledge and pioneering technology and grow methods. On the contrary, when I see members trolling and sharing bad or sarcastic advice, their arguments lose validity.
Sativied
Well-Known Member
Even with a link. Yes of course green leds exist.That however, I like. Interesting. I know growers that use 80 watt green lights... at night (as to not disturb the plants). I also read that green light "CAN" have a positive effect because it's not absorbed very well and therefor penetrates the canopy better. Perhaps that is why heckler noticed an improvement. The reason for the more natural look should however be obvious.Green Light Drives Leaf Photosynthesis More Efficiently than Red Light in Strong White Light: Revisiting the Enigmatic Question of Why Leaves are Green
http://pcp.oxfordjournals.org/content/50/4/684.Abstract
I just concluded, the title actually says: "CXA3070 Drives Leaf Photosynthesis More Efficiently than Red Light in Strong CXA3070 Light"
As for your conclusion however, the doc is about comparing "green light in strong white light" to "red light in strong white light" and not "green light" vs "red light in white light" nor green led vs white led (or not?). It just seems claiming white leds is a waste of lumens while using green leds is odd, hence I asked for clarification.
https://www.google.nl/search?q=green light absorption in plants&espv=2&source=lnms&tbm=isch&sa=X
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I just wanted to say green leds are not very efficient.
But white Leds include a lot of green.
There are other studies.
E.g. in one they completly exchange the blue light for green light at same light Level.
Result was no difference in dry matter/biomass.
So "positive effect" might be understimating its value...
i think what its says, it reaches chloros that are located deeper within the tissue. "Intra leaf".
heckler73
Well-Known Member
Indeed. BTW I didn't add the green LED, myself. The company I purchase from did it on their own (which is funny because I asked them about doing that when I first ordered from them).So you say white leds equals wasting lumen$, but then you add a green led?
I presume the last time I visited this topic and presented papers regarding it, no one paid attention.
Maybe I should re-read these, too.
Sativied
Well-Known Member
Yeah that is what the doc says indeed, I'm talking however about penetrating to lower leaves which I read elsewhere. Don't have an article to link to, read it in a discussion on a more reliable forum, posted by someone from a university in Amsterdam. Hardly a reliable resource by itself, but combined with some logic.... the other colors are more easily and hence "more" absorbed by the first leaves they come in contact with. Clearly not all the green light is reflected (else we'd be blind by now), in fact only little of it, and it's factually less absorbed, so only one way to go and that's to the next leaf.
Actually, having said that, shouldn't be to hard to find a resource that confirms it:
" Another potential advantage of green light is that it can penetrate a canopy better than other wavebands of light."
http://msue.anr.msu.edu/news/green_light_is_it_important_for_plant_growth
Was it lettuce?
Sativied
Well-Known Member
Speaking of lettuce, a better one:
http://www.ncbi.nlm.nih.gov/pubmed/15770792
Green-light supplementation for enhanced lettuce growth under red- and blue-light-emitting diodes.
Plants will be an important component of future long-term space missions. Lighting systems for growing plants will need to be lightweight, reliable, and durable, and light-emitting diodes (LEDs) have these characteristics. Previous studies demonstrated that the combination of red and blue light was an effective light source for several crops. Yet the appearance of plants under red and blue lighting is purplish gray making visual assessment of any problems difficult. The addition of green light would make the plant leave appear green and normal similar to a natural setting under white light and may also offer a psychological benefit to the crew. Green supplemental lighting could also offer benefits, since green light can better penetrate the plant canopy and potentially increase plant growth by increasing photosynthesis from the leaves in the lower canopy. In this study, four light sources were tested: 1) red and blue LEDs (RB), 2) red and blue LEDs with green fluorescent lamps (RGB), 3) green fluorescent lamps (GF), and 4) cool-white fluorescent lamps (CWF), that provided 0%, 24%, 86%, and 51% of the total PPF in the green region of the spectrum, respectively. The addition of 24% green light (500 to 600 nm) to red and blue LEDs (RGB treatment) enhanced plant growth. The RGB treatment plants produced more biomass than the plants grown under the cool-white fluorescent lamps (CWF treatment), a commonly tested light source used as a broad-spectrum control.
I stand corrected, plants don't suck at sucking up that shit if you look at the entire plant instead of a leaf.
http://www.ncbi.nlm.nih.gov/pubmed/15770792
Green-light supplementation for enhanced lettuce growth under red- and blue-light-emitting diodes.
Plants will be an important component of future long-term space missions. Lighting systems for growing plants will need to be lightweight, reliable, and durable, and light-emitting diodes (LEDs) have these characteristics. Previous studies demonstrated that the combination of red and blue light was an effective light source for several crops. Yet the appearance of plants under red and blue lighting is purplish gray making visual assessment of any problems difficult. The addition of green light would make the plant leave appear green and normal similar to a natural setting under white light and may also offer a psychological benefit to the crew. Green supplemental lighting could also offer benefits, since green light can better penetrate the plant canopy and potentially increase plant growth by increasing photosynthesis from the leaves in the lower canopy. In this study, four light sources were tested: 1) red and blue LEDs (RB), 2) red and blue LEDs with green fluorescent lamps (RGB), 3) green fluorescent lamps (GF), and 4) cool-white fluorescent lamps (CWF), that provided 0%, 24%, 86%, and 51% of the total PPF in the green region of the spectrum, respectively. The addition of 24% green light (500 to 600 nm) to red and blue LEDs (RGB treatment) enhanced plant growth. The RGB treatment plants produced more biomass than the plants grown under the cool-white fluorescent lamps (CWF treatment), a commonly tested light source used as a broad-spectrum control.
I stand corrected, plants don't suck at sucking up that shit if you look at the entire plant instead of a leaf.
Sativied
Well-Known Member
I wonder how much of the perceived improvement is from sort of patching a lack of light penetration with LED in the first place. If you have a situation where you have plenty of penetration and proper mj plant/bud site spacing (and sativa leaflets instead of thick fat lettuce) the difference might not be as large, or even noticeable, or worse.
heckler73
Well-Known Member
What 'difference' are you talking about?
Greengenes707
Well-Known Member
You really should look at what I use...
I have said white based many times...
But even all pure warm white works solidly
In the link I gave there you will find the complete article as pdf in which you can find this, so there is no need to talk about lower leaves or canopy penetration, as this still referes to intra leaf:
As Nishio (2000) clearly postulated, and as we have detailed so far, red or blue light is preferentially absorbed by the chloroplasts in the upper part of the leaf. Then, when PPFD is high, the energy of these wavelengths tends to be dissipated as heat by the upper chloroplasts, while green light drives photosynthesis in the lower chloroplasts that are not light saturated ( Sun et al. 1998 , Nishio 2000 ).
At low light conditions you are good with r/b.
In strong light conditions you need to add more green...green leds suck...White leds dont, but have plenty of green...and R and B. Maybe my previous CXA sentence makes more sense now?
If green absorbance was as high as r/b then this would not work
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Greengenes707
Well-Known Member
I am talking about phosphorus conversion whites specifically.
You guys are speaking too much in theories and spectrum specifically...which is fine, and I support for research purposes. But eventually a hypothesis needs to be tested. And tested on our plant or tomatoes is what really needs to happen. Illumitex DS showed a 15% increase in yield over a 1000w hps...in lettuce...not a high light requirement crop.
Also something to take into thought is spectral needs/want change with irradiance levels.
From what is actually available in the physical world right now... whites are showing to be the dominate chips for performance. For more reasons than just their killer spectrums...their efficiency is a huge player too.
If every LED was 100% efficient at converting energy to light photons and there was about 30 more nm's available... then we might be able to come up with a very good mono dominant spectrum and light. But as of now, no matter how good a chosen mono spectrum is...a white led(phosphorus conversion) can supply the same photons more efficiently.
If it was strictly the most efficient blue chip paired with the most efficient red chip available, then it would just barley have a higher efficiency that a pure WW CXA, and potential based on temp droop of the red, could be less than the WW. But I think we have made it clear that even in a mono spectrum more than just one blue and red is needed. So when you start mixing the rest of the needed nm's into the panel/system, the efficiency drops below that of an all white, or white/red combo for that matter.
You example of adding green and seeing improvement is great...but a white phosphorus conversion can fill the same spectral gap more efficiently and is not a waste.
So just for conceptual thinking...
Even if a RGB or multi chip spectrum led was 100% photosynthetically useful...it would have serious wasted energy due to the chips efficiency that would never even get the chance to become a photon in the first place.
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churchhaze
Well-Known Member
Besides penetrating, green and amber will lower %Pfr at the lower branches, which triggers shade avoidance (stretching). Green will cause %Pfr to converge lower than amber, and also penetrate better.
(%Pfr is what I'm calling percent of total phytochrome as Pfr)
Red is the signal that unshaded light has been reached, and to stop stretching.
Phytochromes should be thought of more like color vision the way dogs and cats see (dichromatic).
A lot of people mistakenly call the 3 human cones "blue", "green" and "red" ,but this is based on a misconception. It is not the excitation of the long cone that makes the brain perceive red. If you use a wavelength targeting the peak of the long cone, it will not appear red at all because that wavelength also is heavily absorbed by the medium cone. For a human to perceive red, the long cone must be stimulated all the way at the end of the band, where it doesn't also hit the medium or short cone. It's the ratio of absorbances of the 3 cones that provides the inputs the human brain needs to perceive "color" (something that only exists in the brain).
%Pfr is very analogous to color vision. For any given wavelength, Pr and Pfr will both absorb a certain amount, and the ratio of absorbances will ultimately dictate where %Pfr converges. Similar to color vision, a combination of multiple wavelengths could have an equal effect on %Pfr as one single wavelength, in the same way that spectral green and spectral red together will be perceived by the human brain as yellow, when the same yellow perception can be had using a single wavelength (spectral yellow).
(%Pfr is what I'm calling percent of total phytochrome as Pfr)
Red is the signal that unshaded light has been reached, and to stop stretching.
Phytochromes should be thought of more like color vision the way dogs and cats see (dichromatic).
A lot of people mistakenly call the 3 human cones "blue", "green" and "red" ,but this is based on a misconception. It is not the excitation of the long cone that makes the brain perceive red. If you use a wavelength targeting the peak of the long cone, it will not appear red at all because that wavelength also is heavily absorbed by the medium cone. For a human to perceive red, the long cone must be stimulated all the way at the end of the band, where it doesn't also hit the medium or short cone. It's the ratio of absorbances of the 3 cones that provides the inputs the human brain needs to perceive "color" (something that only exists in the brain).
%Pfr is very analogous to color vision. For any given wavelength, Pr and Pfr will both absorb a certain amount, and the ratio of absorbances will ultimately dictate where %Pfr converges. Similar to color vision, a combination of multiple wavelengths could have an equal effect on %Pfr as one single wavelength, in the same way that spectral green and spectral red together will be perceived by the human brain as yellow, when the same yellow perception can be had using a single wavelength (spectral yellow).
guod
Well-Known Member
the other side of green...
Green light: a signal to slow down or stop
http://jxb.oxfordjournals.org/content/58/12/3099.full
Green-Light-Induced Shade Response
http://www.plantphysiol.org/content/early/2011/08/18/pp.111.180661.full.pdf
-----------------------------------------------------------------
The-Guiding-Force-of-Photons
...
2.2.6 Hypothetical green light receptors
A quick glance at the current receptor collection shows that the visible light spectrum is well
blanketed with the absorption spectra of photosensors to receive it. As noted, the sensor
collection extends plant signal perception clearly into the UV and far-red. Are there truly
responses that cannot be account for by the current set of receptors? Are there likely to be
more ways that a plant can sense the light environment?
A series of green light responses that persist in the absence of known sensors suggest that there are additional players in the plant sensorium.
Green light can excite phytochrome, cryptochrome and phototropin responses, depending
of course on fluence rate and time of illumination.
Green wavebands can induce phytochrome-mediated germination (Shinomura et al., 1996), several effects via cryptochromes as discussed earlier (Banerjee et al., 2007; Bouly et al., 2007; Sellaro et al.,2011), and even phototropic curvature (Steinitz et al., 1985) that in retrospect must be phototropin dependent.
Green light has also been shown to be transmitted efficiently within
the plant body and efficiently drive photosynthesis in deeper layers of the leaf (Terashima et al., 2009).
However, examination of the literature presents a suite of green-light-dependent
phenomena that cannot easily be described as the action of cryptochromes, phytochromes or LOV domain receptors.
These actions are induced specifically by green wavebands (~500-540 nm) and tend to oppose those of red and blue light (for review, Folta and Maruhnich,2007).
Some of the first evidence was noted when plants were grown under white light,
or the same light source with various parts of the spectrum filtered to skew the quality of
illumination.
In early studies Frits Went observed that tomato seedlings grown under white
light (red, blue and green) had a lower dry mass than tomato plants grown under red and
blue light alone (Went, 1957).
The effect was observed across fluence rates, so it was not
simply an effect of limiting photosynthetic capacity.
It was as if the presence of green wavebands contradicted the effects of red and blue.
http://www.intechopen.com/books/advances-in-photosynthesis-fundamental-aspects/the-guiding-force-of-photons
----------------------------------------------------------------------------------
GREEN LIGHT
....
Kim et al. (2006) summarized the experiments with green supplementation of red and blue LED light and concluded that light sources consisting of more than 50% green cause reductions in plant growth, whereas combinations including up to 24% green enhance growth for some species. For more information on plant responses to green light, see Folta and Maruhnich (2007).
http://hortsci.ashspublications.org/content/43/7/1951.full
Green light: a signal to slow down or stop
http://jxb.oxfordjournals.org/content/58/12/3099.full
Green-Light-Induced Shade Response
http://www.plantphysiol.org/content/early/2011/08/18/pp.111.180661.full.pdf
-----------------------------------------------------------------
The-Guiding-Force-of-Photons
...
2.2.6 Hypothetical green light receptors
A quick glance at the current receptor collection shows that the visible light spectrum is well
blanketed with the absorption spectra of photosensors to receive it. As noted, the sensor
collection extends plant signal perception clearly into the UV and far-red. Are there truly
responses that cannot be account for by the current set of receptors? Are there likely to be
more ways that a plant can sense the light environment?
A series of green light responses that persist in the absence of known sensors suggest that there are additional players in the plant sensorium.
Green light can excite phytochrome, cryptochrome and phototropin responses, depending
of course on fluence rate and time of illumination.
Green wavebands can induce phytochrome-mediated germination (Shinomura et al., 1996), several effects via cryptochromes as discussed earlier (Banerjee et al., 2007; Bouly et al., 2007; Sellaro et al.,2011), and even phototropic curvature (Steinitz et al., 1985) that in retrospect must be phototropin dependent.
Green light has also been shown to be transmitted efficiently within
the plant body and efficiently drive photosynthesis in deeper layers of the leaf (Terashima et al., 2009).
However, examination of the literature presents a suite of green-light-dependent
phenomena that cannot easily be described as the action of cryptochromes, phytochromes or LOV domain receptors.
These actions are induced specifically by green wavebands (~500-540 nm) and tend to oppose those of red and blue light (for review, Folta and Maruhnich,2007).
Some of the first evidence was noted when plants were grown under white light,
or the same light source with various parts of the spectrum filtered to skew the quality of
illumination.
In early studies Frits Went observed that tomato seedlings grown under white
light (red, blue and green) had a lower dry mass than tomato plants grown under red and
blue light alone (Went, 1957).
The effect was observed across fluence rates, so it was not
simply an effect of limiting photosynthetic capacity.
It was as if the presence of green wavebands contradicted the effects of red and blue.
http://www.intechopen.com/books/advances-in-photosynthesis-fundamental-aspects/the-guiding-force-of-photons
----------------------------------------------------------------------------------
GREEN LIGHT
....
Kim et al. (2006) summarized the experiments with green supplementation of red and blue LED light and concluded that light sources consisting of more than 50% green cause reductions in plant growth, whereas combinations including up to 24% green enhance growth for some species. For more information on plant responses to green light, see Folta and Maruhnich (2007).
http://hortsci.ashspublications.org/content/43/7/1951.full