730NM good or bad?

After looking at the IG pontoon have been doing some reading up on this "flower initiator" range of 730nm

searching the net I found this post from a guy who actually has his own LED light company and was wondering what our more knowledgeable growers had to say.

"4) No studies show any advantage to 730nm light, in fact 730nm switches a main flowering hormone from its active to inactive state!"

When they're talking making the hormone inactive theyre talking about the pfr-->pr state (I always get em backwards) but its basically when the plant enters flower/true darkness, there's a time lapse just like for ppl tht plants take to "fall asleep," that trigger shortens it, which lets you run lights longer/shorter dark cycle.

730 all day long is supposed to stretch the fuck out of your kids so id say just a trigger.

Im aware of running it for short periods after lights out... I just dont see where the disadvantage comes from making your plants "sleep" faster

Just thought since you said "730nm switches a main flowering hormone from its active to inactive state" I thought I'd clarify. And maybe I'm wrong, it's a pretty gray area for me. Chaz is your best source. I don't see to many disadvantages to faster dark cycles on a blooming plant though.

%Pfr = Pfr / (Pfr+Pr)

Think of %Pfr like plants' color vision. Pfr and Pr are like 2 cones in plant vision. The difference in "cone" absorbances gives the plant a gradient to tell how high the "quality" of the light is.

Certain wavelenths like 660nm will make %Pfr very high. Pure 660n light will put %Pfr at around 85%. This is because Pfr and Pr both absorb at 660nm, so you can't ever get %Pfr to 100%.

You can get %Pfr to 0% though, because Pr doesn't absorb at 730nm but Pfr does. This means 730nm will cause %Pfr to go all the way to 0%. (all Pfr converted to Pr).



If you were to shine just 500nm at the plant, from this chart, %Pfr would converge at around 50%, since Pr and Pfr absorb equally there. (assuming that chart is correct)

The chart also shows that light between 340nm and 390nm will raise %Pfr above 50% while light between 390 and 460nm will lower it below 50%. Not exactly relevant to this particular question, but maybe interesting to people who haven't thought about that yet.

Some hints from my latest ( still ongoing day & night ) research for developing
a " photosynthetic efficiency action spectrum standard " ,
speciffically for (Cannabis Sativa L . ) .
(World's first one ? )

Some hints only ,for now ...

......................


................................................



.........




For driving PS , light > 700 nm is wasted watts ..
Better have green leds ,instead !! (just kiddin'... _ ..._
For photomorphogenesis ,might not be the case ...

Cheers.

you think 730 is of no value SDS?... is that how I read that article?

730nm will only cause stretch during the day, but some 730nm will help shade avoidance. This is because of how well 730nm penetrates, but 660nm doesn't penetrate. The lower levels will see more 730nm, and stretch until they also see 660nm.

This shade avoidance effect is also provided by all colors though, like amber, since it amber on its own will cause %Pfr to go lower than amber + red. Lower branches have all the red filtered out and will stretch.

spazatak said:

you think 730 is of no value SDS?... is that how I read that article?

Click to expand...

churchhaze said:

730nm will only cause stretch during the day, but some 730nm will help shade avoidance. This is because of how well 730nm penetrates, but 660nm doesn't penetrate. The lower levels will see more 730nm, and stretch until they also see 660nm.

This shade avoidance effect is also provided by all colors though, like amber, since it amber on its own will cause %Pfr to go lower than amber + red. Lower branches have all the red filtered out.

Click to expand...

do you think its worth 5 to 10 minutes of it at lights out or not..

so far I have heard both sides of the story... some say its necessary and other not.... it was never my intention to run it all the time and only really considered it after reading about the IG pontoon

From watching positivity's and captain morgan's grows, I would say it makes a big difference. Positivity did a test in his thread where he omitted the 730nm pulses, and the results were about 1 week of delayed flowering onset and finishing.

I don't have personal experience with leds, but I've been watching these threads to confirm the science/theory I've been reading about is true. Positivity also seems to have a much cheaper 730nm solution than captain morgan.

spazatak said:

do you think its worth 5 to 10 minutes of it at lights out or not..

so far I have heard both sides of the story... some say its necessary and other not.... it was never my intention to run it all the time and only really considered it after reading about the IG pontoon

Click to expand...

churchhaze said:

From watching positivity's and captain morgan's grows, I would say it makes a big difference. Positivity did a test in his thread where he omitted the 730nm pulses, and the results were about 1 week of delayed flowering onset and finishing.

I don't have personal experience with leds, but I've been watching these threads to confirm the science/theory I've been reading about is true. Positivity also seems to have a much cheaper 730nm solution than captain morgan.

Click to expand...

thanks man.. I know Hy and Capt seem to think its worthwhile....

will ask Pos about his technique

730 will also contribute to making buds denser Texas A&M has a study on infrared light and the effect on plants

spazatak said:

thanks man.. I know Hy and Capt seem to think its worthwhile....

will ask Pos about his technique

Click to expand...

hyroot said:

730 will also contribute to making buds denser Texas A&M has a study on infrared light and the effect on plants

Click to expand...

Right now ,I just want to throw and bury myself in the =>hole<= I've dig up .....

stardustsailor said:

Some hints from my latest ( still ongoing day & night ) research for developing
a " photosynthetic efficiency action spectrum standard " ,
speciffically for (Cannabis Sativa L . ) .
(World's first one ? )

Some hints only ,for now ...
View attachment 3179767
......................

View attachment 3179768
................................................

View attachment 3179769

.........

View attachment 3179772


For driving PS , light > 700 nm is wasted watts ..
Better have green leds ,instead !! (just kiddin'... _ ..._
For photomorphogenesis ,might not be the case ...

Cheers.

Click to expand...

Spinning head.

churchhaze said:

%Pfr = Pfr / (Pfr+Pr)

Think of %Pfr like plants' color vision. Pfr and Pr are like 2 cones in plant vision. The difference in "cone" absorbances gives the plant a gradient to tell how high the "quality" of the light is.

Certain wavelenths like 660nm will make %Pfr very high. Pure 660n light will put %Pfr at around 85%. This is because Pfr and Pr both absorb at 660nm, so you can't ever get %Pfr to 100%.

You can get %Pfr to 0% though, because Pr doesn't absorb at 730nm but Pfr does. This means 730nm will cause %Pfr to go all the way to 0%. (all Pfr converted to Pr).

If you were to shine just 500nm at the plant, from this chart, %Pfr would converge at around 50%, since Pr and Pfr absorb equally there. (assuming that chart is correct)

The chart also shows that light between 340nm and 390nm will raise %Pfr above 50% while light between 390 and 460nm will lower it below 50%. Not exactly relevant to this particular question, but maybe interesting to people who haven't thought about that yet.

Click to expand...

Right now,I'm making a spreadsheet tool (it all started from 'decoding' CXA3070's rel.power graph ...LOL),
specially for analysing a LED/COB 's output light ...

In plant biology terms and units ,not just Volts,Watts,Lumens(!) , Amperes,etc ...

-It already features analytical "25 nm band" ,measurements of quantum flux for the range of 380-780 nm ..

-A Cannabis Sativa L. species dedicated ,leaf Lamina Adaxial Reflection & Abaxial Transimission of quanta,
estimation/ calculation

-Thus the cannabis leaf Absorptance is estimated ,
as part of a new Rel.Quantum Yield .
Cannabis species dedicated !
(It incorporates also the McCree,1972 RQE in it's functions... )

-Daily light Integral figures for 12 /16 /18 and 20 hour irradiation regimes " per dia "
(The plant's "day cycle" = dia =latin for day ...Carpe Diem !)

-Photosynthetically Active Weighted spectral plot and info of output light ...

-I'm thinking about adding a "SSL Photoinhibitory Efficiency " ..
Although kida tricky this one ...
(have to combine more than few photoreceptor pigment's action spectra ,with
aΦ generallized photoinhibition efficiency spectrum ..)


And right now I'm working on phytochrome ...
(wiil have the feature of two separate plots of light output ,one for Pfr ,one for the Pr ...
A combined -convolved one ...LED's -Cob's Pfr / Pr ratio and the PPE/PPtostationary state value of the led/cob ..(Pfr / Phy total )
(phytochrome photo equilibrium aka phytochrome photo stationary state ...)


I got also a good plot to digitize ...









And something about the % of Pfr / Pr ...

"
D. Efficiency of photoconversion
Phytochrome acts like a weird light switch that only turns off/on a portion of the lights. In other words, red light treatment of Pr results in about 85% Pfr + 15% Pr; far red light treatment of Pfr results in 97% Pr + 3% Pfr. Thus, at photo-equilibrium not all the phytochrome is interconverted. The reason for this is because the absorption spectra for the two pigments overlap and they are essentially competing reactions.

A measure of the efficiency conversion is the ratio of the Pfr to the total which is expressed as follows:

efficiency = Pfr/(Pr+Pfr = phytochrome total)

In red light = 0.85; far red 720 nm = 0.03; this varies with the environment (see text and overhead)


http://employees.csbsju.edu/ssaupe/biol327/Lecture/phytochrome.htm

http://cpl.usu.edu/files/publications/poster/pub__6740181.pdf


Analysing the led's/COB's biological (plant growth ) abilities and capabilities to deepest possible ....
All it takes is a digitizer a calc/spreadsheet ,some time & plenty of love for the art/science of it ...

Everything else (data,research papers,plots,pics ,etc ) are a piece of cake ,to be found ...

(Ok ,in fact I'm doing some 'smart-ass ' math work ,using other's reseaches and results ..
Information and data ,already available... )

Cheers.

Sorry SDS but I am posting this meme again...


you mad scientist

Pr to go ....

Cheers..

Well.... read the thread with a glass of moonshine...I don't get it. There are some people who say that it works, some say it don't work. So who is going to test it out with a dual test like greengenes707 did with a led and hps test.The fastest string can flower in 6 weeks (so I heard), so who can make it in 5 weeks?

The things we do know:

1) 730nm penetrates the canopy very well. It is not absorbed very well by chlorophyll.
2) 730nm will cause Pfr as a percent of total phyotochromes to converge lower, as low as ~3% with pure 730nm.
3) Pfr is local. Shaded leaves and growth tips will have a lower Pfr than unshaded canopy level leaves/tips.
4) Lower Pfr during the day will mean more shade avoidance of lower (shaded) branches (stretch)

The things we don't know is how much and when will yield the most buds the fastest. It's easy to make sound decisions based on false assumptions of what configuration will work the best.

happy75 said:

Well.... read the thread with a glass of moonshine...I don't get it. There are some people who say that it works, some say it don't work. So who is going to test it out with a dual test like greengenes707 did with a led and hps test.The fastest string can flower in 6 weeks (so I heard), so who can make it in 5 weeks?

Click to expand...