FR question

D

Devildenis69

Well-Known Member
Thx for all your answers !

md2of2, thx for remending me the emmerson effect, I've read things about it before and forget it
so to summerise, these experience shows a "red drop" in photosynthesis after 680nm if this wavelength is used alone
when Ir were used in combination with a wavelength lower than 660nm, the production of O2 is superior than the addition of production under these 2 wavelngths separated ...
so far the use of 730 in addition of vero18 looks like a good idea

AP: ill-effects with 730nm ? regarding the sun spectrum, it's quiet surprising for me, could you tell me more please ?

churchhaze: you're highlighting very important things.
as a large portion of the spectrum affects the Pr/Pfr ratio and as we don't know the exact leaf composition (I mean proportions), calculating Pr/Pfr seems to be ... complicate.
and do you think that sas may reduce the yield ? or other bad effects ?

Positively: you're speaking about a 730/660 balance ... that's exactly the thing I can't understand
what's the 660nm use during flowering ? It's has similar efficiency than 630nm, which fewer Pr/Pfr impacts
at least, those who are "growing with the moon" cares about the auxines to be in budz when they cut ... 660nm does the opposite.
 
M

md2of2

Well-Known Member
The EEE dealt with R and FR not IR. A water filter was used to omit IR wavelengths but yes your right the sum of the whole was greater than the sum of the parts.

Church can you explain this statement better, "The unique feature of phytochrome is that it exhibits photoreversibility; it exists in two forms that are interchangeable. Pr - red light absorbing form and Pfr - far red light absorbing form. When Pr absorbs red light (ca. 660 nm) it is converted into Pfr. When Pfr absorbs far red light (ca. 730 nm) it is converted into Pr.". So could we say that with no FR Pfr would not change to Pr except during lights out, with te exception of the overlap in wavelengths

As I understand Pfr is active and Pr is inactive, and Pfr returns to PR at night. When the plant is hit with those 2 wavelengths wouldn't the P's be constantly reverting to the others form.

Also I've read that the phytochrome protein is more easily digested while in the Pfr form.

Of course I've only cut plants at night when I had to, not by choice. At the risk of being an asshole I'm gonna say the moonlight thing is snake oil.
 
C

churchhaze

Well-Known Member
There is actually no way to convert all Pr to Pfr because both Pfr's absorbance overlaps Pr's aborbance.



Even using pure 660nm light, it's still impossible to convert all Pr to Pfr because Pfr absorbs some at 660nm too. The theoretical maximum %Pfr is ~85%. Since there is no overlap at 730nm, it is possible to get %Pfr to 0%, however. (All phytochrome in Pr state)

Yes, basically it will just convert back and forth, converging at an equilibrium based on the wavelength. Where Pfr and Pr absorbance intersects (about 500nm and 700nm), you should theoretically get 50% Pfr. That's why I like to use the color vision analogy. It's not as straight forward as stimulating peaks, but more like a gradient.


md2of2 said:
Church can you explain this statement better, "The unique feature of phytochrome is that it exhibits photoreversibility; it exists in two forms that are interchangeable. Pr - red light absorbing form and Pfr - far red light absorbing form. When Pr absorbs red light (ca. 660 nm) it is converted into Pfr. When Pfr absorbs far red light (ca. 730 nm) it is converted into Pr.". So could we say that with no FR Pfr would not change to Pr except during lights out, with te exception of the overlap in wavelengths

As I understand Pfr is active and Pr is inactive, and Pfr returns to PR at night. When the plant is hit with those 2 wavelengths wouldn't the P's be constantly reverting to the others form.

Also I've read that the phytochrome protein is more easily digested while in the Pfr form.

Of course I've only cut plants at night when I had to, not by choice. At the risk of being an asshole I'm gonna say the moonlight thing is snake oil.
Click to expand...
 
M

md2of2

Well-Known Member
Excuse me but I'm gonna ramble. Could it be that AP's 760 nm at lights out excelerates the process of Pfr changing to Pr thus allowing fr a 13.5/10.5 schedule, or does that happen more rapidly than I'm imagining. Possibly it helps to achieve a 0% Pfr, although I think I've read that it's a maximum 97% Pr to 3% Pfr at lights out. If this is true than can we do something at lights on to excelerate them reaching equilibrium. Perhaps blast them with only 660nm for a few minutes before the introduction of the rest of the spectrum.
 
8

8/10

Well-Known Member
Church, you seem to have quite a grip on this stuff, and it seems very interesting. a little hard to follow for someone like me, with almost no knowledge on this subject, but is all this translatable in evolutionary mechanisms, like the "lower branches in the shadow" thing? Seems like the plant equates FR with what we call "dark" is that right? Like it has no "lack of light" -sensor, it has an FR-sensor instead?

I would definitely like to know more about this subject and eventually implement some FR in my grow, although it's hard to document effects with all the variables involved in a grow and the amount of time between results...
 
M

md2of2

Well-Known Member
I don't think that's right. The plants circadian clock is controlled by cryptochrome proteins which are reactive to blue lights.
 
8

8/10

Well-Known Member
okay, I'm with you. But that just means the plant doesn't use its "dark" sensor to determine the circadian rhythm, but its "blue" -sensor, right?

or wrong?

Also, cryptochrome is an awesome word!

EDIT: I was initially thinking it used FR to determine night-time
 
M

md2of2

Well-Known Member
I believe no blue = dark thus begins the calvin cycle. I could be wrong, or not completely right though as there are many systems that work in unison, but I think that is the main factor.
 
8

8/10

Well-Known Member
I'm reading a little on the subject atm and it is very interesting... But being scientific talk, it's very "slowly digestible" if you know w i m. Funny thing, I had a dream tonight about all this and I was measuring light levels in the grow room with my dlsr camera, lol. wonder if that would work, tho? I know the light sensor on these things are pretty awesome. This dude on youtube detected an exoplanet by measuring a drop in light levels emitted from a star with his normal dlsr camera.
 
D

Devildenis69

Well-Known Member
Hello,

the moon thing is about gravity not light (sure you know it, just to be sure)
haven't used it yet for cutting, but cloning works greater for me, when I do it at the right time ...

end of the flowering, the plant is not absorbing so much nutiment by roots, beginning to get it from leafs ...
why would I like to make my auxines go back to roots ? 660nm has this effect ...

I'm maybe wrong, but as I understand, the Pr are blinding the circadian clock, that's why they fall asleep faster

8/10, funny dream, most of our dlsr's captors can detect wavelngth outside of the visible spectre, but these wavelength are blocked by a filter, that can be removed ...

here's an article posted by SDS sooner, treating about this Pr/Pfr ratio, haven't understood everything, but still very interesting
http://www.hindawi.com/journals/isrn/2013/650439/

and about accelerating the flowering passage, there's something about a "flowering locus T" protein, linked to all that Pr/Pfr stuff, this protein seems to be stimulated by Pr presence
 
Last edited:
AquariusPanta

AquariusPanta

Well-Known Member
So much rambling has taken place since I last posted. :grin:

While the LED stars I use were sold as hyper far red (730 nm), they are technically IR but for the sake of conversation, they are FR.

Md2 is on the correct track with how the pFR within the plant is turned over to pR within sometimes seconds of FR (730nm) use, hence Positivity's comment of pulsing 730nm right at lights out. This is what typically takes 2 hours to normally do for a plant grown indoors without a dedicated FR star (730nm) after lights out but with FR at lights out, you reduce the process from ~2 hours to minutes or even seconds, allowing a 13.5/10.5 light scedule during flowering.
 
C

churchhaze

Well-Known Member
I don't have any evidence to back this up, but I think that cryptochromes are more responsible for sensing light intensity while phytochromes is used to sensing light "quality".

I remember reading somewhere that higher cryptochrome stimulation results in more chlorophyll development, and causes some plants to purple, and maybe develop more resin?

Considering that we're taking time off flowering using FR, i'd guess that phytochromes play a bigger role in the circadian rhythm of plants, but I mean that's all theoretical my current guess.
 
Last edited:
C

churchhaze

Well-Known Member
730nm is usually refered to as FR or NIR (near infrared). 700-900nm is basically considered NIR, but 730nm is very visibly red and thus hard to not call red.

The real problem with calling them IR leds, or even NIR, is that people might get confused and think 800nm or even 900nm will also be good. (used for things like TV remote control and night vision). The thing is we all specifically mean 730nm, and 800nm is not an acceptable replacement. IR is a huge range of the spectrum in terms of wavelength, and by itself is just not specific enough to mean anything.

AquariusPanta said:
So much rambling has taken place since I last posted. :grin:

While the LED stars I use were sold as hyper far red (730 nm), they are technically IR but for the sake of conversation, they are FR.

Md2 is on the correct track with how the pFR within the plant is turned over to pR within sometimes seconds of FR (730nm) use, hence Positivity's comment of pulsing 730nm right at lights out. This is what typically takes 2 hours to normally do for a plant grown indoors without a dedicated FR star (730nm) after lights out but with FR at lights out, you reduce the process from ~2 hours to minutes or even seconds, allowing a 13.5/10.5 light scedule during flowering.
Click to expand...
 
AquariusPanta

AquariusPanta

Well-Known Member
churchhaze said:
730nm is usually refered to as FR or NIR (near infrared). 700-900nm is basically considered NIR, but 730nm is very visibly red and thus hard to not call red.

The real problem with calling them IR leds, or even NIR, is that people might get confused and think 800nm or even 900nm will also be good. (used for things like TV remote control and night vision). The thing is we all specifically mean 730nm, and 800nm is not an acceptable replacement. IR is a huge range of the spectrum in terms of wavelength, and by itself is just not specific enough to mean anything.
Click to expand...
I agree with your words, brother.
 
8

8/10

Well-Known Member
happy75

happy75

Well-Known Member
8/10 said:
What do you guys think of these:

http://www.ebay.com/itm/5pc-3W-high-power-3535-730-740nm-Infrared-LED-Light-IR-led-chip-with-20mm-star-/251725009577?pt=LH_DefaultDomain_0&hash=item3a9bfad2a9

Are they even Cree? And if so, is that model dated or what, cause I can't seem to find the datasheets or any info on them.

I've tried stevesleds, but the shipping fee is way out of the question. Looking for Luxeons on ebay and alibaba as well.
Click to expand...
China.... they say that they deliver the best and newest leds, but you get the old ones. If its only for a few minutes a day, then it does not matter for efficiency, is my opinion. Led tech in Germany has also crees, but I don't see far red on their website. I will give them an email.
 
8

8/10

Well-Known Member
Okay, and how would one go about wiring these leds to only power on for a few minutes after lights out?
 
happy75

happy75

Well-Known Member
happy75 said:
China.... they say that they deliver the best and newest leds, but you get the old ones. If its only for a few minutes a day, then it does not matter for efficiency, is my opinion. Led tech in Germany has also crees, but I don't see far red on their website. I will give them an email.
Click to expand...
The germans don't have the cree far red.
@8/10 Good question, I am wondering this myself. I think to use a digital timer but every timer need to be exact on time. Or doesn't it matter if it somewhat overflows (the white and the red).
 
You must log in or register to reply here.
Top