First Grow journal - 320W - 3X3 - Organic

[LivingLight]

Do you have any recent studies link about this to back up your claim? (far-red + deep-red)? I've talk to some experienced & known led grower & most of them are saying that 700+nm is a waste of energy during day cycle. (exemple)

I'm currently using 730 cree led to test phytochrome manipulation & if you have any decent info on how far red can improve my spectrum, I would love to try balancing the 660 with some 730 on my 3x3 lights.

First, you probably know about the SAS. I mean no need to quote an article right?
So first, a balanced SAS allow you to optimise photosynthetic activity, by weighting the leaf size, the chloroplast organisation, the photoprotection process and a lot of other major photosynthetic actors.
I unfortunately got no study to quote because with time and gathering infromations from many articles, it became really obvious to me and i've never found an article that gather the whole informations.
Anyway that means using far-red to balance phytochromes thus the SAS, lead to improved photosynthetic efficiency.

then, i think the two next studies shows very well the most important parts of the phytochromes interactions on the flowering and the senescence:

Phytochrome mediates the external light signal to repress FT orthologs in photoperiodic flowering of rice
Takeshi Izawa, Tetsuo Oikawa, Nobuko Sugiyama, Takatoshi Tanisaka, Masahiro Yano,
and Ko Shimamoto1, 2007

In this study on the rice (short day plant) the measurement on the flowering locus and the Constans messengersRNA for Phytochromes deficient mutants shows that the flowering gene is repressed both by the circadian clock genes depending on the day/night cycle (so indirectly depending on the phytochromes) and directly by the phytochrome activation during the day. That would means : the more you activate the phytochromes during the day, the more you delay flowering. In addition to the well known effect of phytochromes at the nightfall.
You could try to use a blurple and only add 730nm at nightfall, your flowering induction still willl be delayed compared to a full spectrum with lower phytochrome ratio.


Phytochrome-interacting transcription factors PIF4 and PIF5 induce leaf senescence in Arabidopsis
Yasuhito Sakuraba1, Jinkil Jeong, Min-Young Kang, Junghyun Kim, Nam-Chon Paek & Giltsu Choi, 2014

Here they literally says:
". ELF3 and phytochrome B inhibit
senescence by repressing PIF4/PIF5 at the transcriptional and post-translational levels,
respectively. PIF4/PIF5 act in the signalling pathways of two senescence-promoting
hormones, ethylene and abscisic acid, by directly activating expression of EIN3, ABI5 and EEL"
So basically, something that everyone should know, the phytochrome activation during the day delay senescences.
Whatever the origin of the senescence (age triggered, lack of food...)
Also if you've ever been using blurple this appear to be really obvious xD

I don't really like to read what other growers says on colours because they have no solid scientific knowledge and they usually says things they can't prove. I personally make my own opinion with my experience and reading hundreds of studies AND selecting them. Because even in the scientific society, there is a lot of bullshit and bad articles

[Hyakutak]

Do you have any recent studies link about this to back up your claim? (far-red + deep-red)? I've talk to some experienced & known led grower & most of them are saying that 700+nm is a waste of energy during day cycle. (exemple)

I'm currently using 730 cree led to test phytochrome manipulation & if you have any decent info on how far red can improve my spectrum, I would love to try balancing the 660 with some 730 on my 3x3 lights.

First, you probably know about the SAS. I mean no need to quote an article right?........

Thank you for this in-depth answer!

I've never used blurple light so I don't have any experience w/ them. The growers I usually quote/link are just like you, very science driven (SuperAngryGuy, LedWizard, etc). But I'm not in the biology/botany field, so I'm just trying to find the best pieces of information I can out there and filter commercial bullshit.

But I'm still not sure about far red utility & deep red danger... I've talked with SuperAngryGuy (I've seen you quoted him in the past days right?) and he recommends the following

The Emerson effect was shown to work with certain bacteria algae. Bacteria and algae can have chlorophyll types C-F instead of just A and B. Some are red edge sensitive (around 700nm).

People just assumed it would also work with plants in real life situations. The maximum absorption of chlorophyll in leaves is 680nm. By 700nm a lot of the light is starting to be scattered by the light and by 730nm very little light is absorbed by the plant. You can see in this reflectance chart of a high nitrogen marijuana leaf:

http://i.imgur.com/tdKIr.jpg

Be careful of "confirmation bias" on marijuana forums when technical stuff gets talked about. You really need a spectrometer for this sort of work including chlorophyll fluorescence measurements typically with a pulse amplitude modulated laser as a fluorescence pump source so measurements can be taken in full lighting conditions.

Far red can trigger more yield in some plants. This likely has to do with greater leaf expansion for more light capture earlier in the plant's grow cycle rather than an Emerson effect. Begonias, a long day plant, can flower earlier with no loss in yield at 8% far red light (unpublished research, Roberto Lopez, MSU). Cannabis is a short day plant, though.

I would recommend 660-670nm and 700nm LEDs. You can get 700nm, 710nm, 720nm LEDs on eBay (where I got mine when testing this). You need to verify the wavelength with a spectrometer since I was getting the wrong wavelengths when I ordered including some that were actually 850nm LEDs.

That's why I took the 660 nm - 700 nm road.

I also talked with fluence about far red and here is a glimpse of what they know about it:

I must be candid, we do not have any clear guideline on how to use the PfrSpec for Cannabis. Although it is very promising technology, and there is documentation on usage for other crops, the verdict is really still out for Cannabis. The concern is that the amount of far red required to have the desired effect could excite other photosystems as well, so you will probably need precise timing and intensity control. For the time being, we offer these as "research" spectra, since we can't tell you exactly how to use them.

We do believe that there are ways to use far-red effectively, but there have been different approaches to their application.

I we analyze a bit the Fluence spectrum, they seem to have a lot of 660nm red (with a little bit of 680-700nm):



Fluence seems to work very hard on their spectrum & knowledge and not just selling marketing bullshit. So I kinda trust them.

I'm still trying to find good information about deep-red & far red. But no one seems to be sure about anything. And Far-red seems to affect different cannabis strain in a different manner. So I'm really lost right now.

[LivingLight]

I we analyze a bit the Fluence spectrum, they seem to have a lot of 660nm red (with a little bit of 680-700nm):



Fluence seems to work very hard on their spectrum & knowledge and not just selling marketing bullshit. So I kinda trust them.

I'm still trying to find good information about deep-red & far red. But no one seems to be sure about anything. And Far-red seems to affect different cannabis strain in a different manner. So I'm really lost right now.

Well, there is no evidence on the utility of the 680-700nm range isn't it?
The emerson effect, if i remember well, is way stronger for 700+nm. Anyway emerson is one of the very little optimisation that is overestimated. I got numbers from a recent study if you are interested
Of course every strain is affected in a different manner. But it's not working at the opposite of an other.
Phytochromes interactions are well known nowadays, for me it is quiet clear

most people focus on little details on the photosynthetic curves or whatever and miss the huge physiological needs of their plants
And the "fluence" answer to you on far red looks like politic speech xDD

[LivingLight]

The ambiguity on far-red, i think got 3 origins:

first the emerson effect, we don't really care a lot about that because its effect is minimal.
Marketing around emerson effect make people lost the first goal of the spectrum optimisation.

second is the ambiguity of phytochromes responses:
a high Pfr/Pr rate delay flowering for sure but that doesn't means we don't have to use red, let me explain.
There are two distinct kind of phytochrome responses. One highly depend on the Pfr/Pr rate, and the other (HIR), less understood, depend more on the global activation. that means you can trigger some phytochromes effect using a lot of red but in the same way, balance the effects it could have on the Pfr/Pr rate using far-red. In a way, that's exactly what the solar spectrum is doing.

Third ambiguity is on the phytochrome diversity of effects on the SAS, the Circadian clock, and the flowering locus..
You'll need to understand all these interactions to use the red and the far-red smartly.

[Hyakutak]

Well, there is no evidence on the utility of the 680-700nm range isn't it?

https://en.wikipedia.org/wiki/P700

PSI is 680-700, PSII is 680- (in cannabis afaik). Emerson effect isn't working w/ far red, this is the combination of PSI & PSII.

Yes the fluence answer is quite "political", but I was asking information about their far-red only lights. So they are quite honest about what they know about their product. Is kinda rare in this industry.

Anyway, I do have some spare 730nm led to play with the PFR during flowering. Do you have any ratio (660 / 730) recommendations?

Both are Cree XP-E. HE photo red & far red.

660 is 425mW
730 is 250mW

[LivingLight]

Yes the fluence answer is quite "political", but I was asking information about their far-red only lights. So they are quite honest about what they know about their product. Is kinda rare in this industry.

Anyway, I do have some spare 730nm led to play with the PFR during flowering. Do you have any ratio (660 / 730) recommendations?

Both are Cree XP-E. HE photo red & far red.

660 is 425mW
730 is 250mW

A simple ratio is not enough. It depend on the rest of your spectrum. I can make some simulations if you tell me more about your spectrum and about your setup conditions

Well, there is no evidence on the utility of the 680-700nm range isn't it?

https://en.wikipedia.org/wiki/P700

PSI is 680-700, PSII is 680- (in cannabis afaik). Emerson effect isn't working w/ far red, this is the combination of PSI & PSII.

Don't worry i know how is emerson effect working. And btw PSI extend beyond 700nm
But according to a study i've been reading, the stronger emerson effect seems to appear using far-red around 720nm:

Far-Red Spectrum of Second Emerson Effect: A Study Using Dual-Wavelength Pulse Amplitude Modulation Fluorometry
V.S. Lysenko, T.V. Varduny, E.I. Simonovich, O.I. Chugueva, V.A. Chokheli, M.M. Sereda, S.N. Gorbov, V.P. Krasnov, E.K. Tarasov, I.Y. Sherstneva and M. Yu Kozlova, 2014

If you are not targeting the stronger emerson effect you won't get any benefit from it, it's already so weak

[LivingLight]

To illustrate the PSI and PSII range here is a graph (don't remember the specie but you can check on the study)


Action spectra of photosystems II and I and quantum yield of photosynthesis in leaves in State 1
Agu Laisk, Vello Oja, Hillar Eichelmanna, Luca Dall'Osto

On this graph it appeared to be logical that the optimum for emerson enhancement should be found around 720nm

[Hyakutak]

Yes the fluence answer is quite "political", but I was asking information about their far-red only lights. So they are quite honest about what they know about their product. Is kinda rare in this industry.

Anyway, I do have some spare 730nm led to play with the PFR during flowering. Do you have any ratio (660 / 730) recommendations?

Both are Cree XP-E. HE photo red & far red.

660 is 425mW
730 is 250mW

A simple ratio is not enough. It depend on the rest of your spectrum. I can make some simulations if you tell me more about your spectrum and about your setup conditions

Well, there is no evidence on the utility of the 680-700nm range isn't it?

https://en.wikipedia.org/wiki/P700

PSI is 680-700, PSII is 680- (in cannabis afaik). Emerson effect isn't working w/ far red, this is the combination of PSI & PSII.

Don't worry i know how is emerson effect working. And btw PSI extend beyond 700nm
But according to a study i've been reading, the stronger emerson effect seems to appear using far-red around 720nm:

Far-Red Spectrum of Second Emerson Effect: A Study Using Dual-Wavelength Pulse Amplitude Modulation Fluorometry
V.S. Lysenko, T.V. Varduny, E.I. Simonovich, O.I. Chugueva, V.A. Chokheli, M.M. Sereda, S.N. Gorbov, V.P. Krasnov, E.K. Tarasov, I.Y. Sherstneva and M. Yu Kozlova, 2014

If you are not targeting the stronger emerson effect you won't get any benefit from it, it's already so weak

SAG's long answer about why emerson effect won't work w/ + 700nm on cannabis.

Thank you for proposing to simulate the best spectrum. What are you using to do that?

Currently, I'm working with 5x 3500k 144 diodes lm561c with 21x 660 nm red cited above.

[LivingLight]

SAG's long answer about why emerson effect won't work w/ + 700nm on cannabis.

Lol this guys is out of the sientific reality i'm sorry
It's nice that people are investigating the question, but they stay at the surface when a scientist dig deeper

check this article using 730nm leds:
Far Red light is needed for efficient photochemistry and photosynthesis.
Shuyang Zhen, Marc W. van Iersel
Department of Horticulture, University of Georgia
Published in the Journal of Plant Physiology, 2017 edition

And check the graph i just post before your last post. He is thinking on old research that was actually investigating 680-700nm but now we got better studies.

Thank you for proposing to simulate the best spectrum. What are you using to do that?

Currently, I'm working with 5x 3500k 144 diodes lm561c with 21x 660 nm red cited above.

I'm using my own calculator.
What is the bin of your lm561c? and what intensity? or maybe what is the exact ref of your white strips

[Hyakutak]

I will check all the paper tonight, thank you very much!

Actual strip: SI-B8V521560WW