...All Things Vero...

[AquariusPanta]

so that's a yes then. It is wasted light

I believe the point that Supra, GGenes, and Alesh were making was that while the 90-97CRI versions of the Vero 10 have a slice extra of 670-700nm spectra range, the 80CRI makes up for it in the 600-660nm spectra range (V2.0).

Maybe you already knew this, idk.

 

[churchhaze]

500-600nm penetrate extremely well because of it's low absorbance by chlorophyll a and b.

Most red is absorbed in the top canopy level, so 500-600nm is very useful for taller plants.

It also will cause %Pfr to converge at a lower level, which could actually be very good for flowering response, and also helps promote shade avoidance effect.

Just because 500-600nm isn't absorbed as easily doesn't mean they aren't as useful at powering photosynthesis.

 

[AquariusPanta]

500-600nm penetrate extremely well because of it's low absorbance by chlorophyll a and b.

Most red is absorbed in the top canopy level, so 500-600nm is very useful for taller plants.

It also will cause %Pfr to converge at a lower level, which could actually be very good for flowering response.

I'm under the impression that plants do not use 500-600nm, hence why they are green. Would you say 500-600nm is more helpful than harmful for plants or vice-versa?

edit: after your edit, my question appears silly. thanks for the input

 

[PSUAGRO.]

500-600nm penetrate extremely well because of it's low absorbance by chlorophyll a and b.

Most red is absorbed in the top canopy level, so 500-600nm is very useful for taller plants.

It also will cause %Pfr to converge at a lower level, which could actually be very good for flowering response.

Just because 500-600nm isn't absorbed as easily doesn't mean they aren't as useful at powering photosynthesis.

Like +

 

[Greengenes707]

so that's a yes then. It is wasted light

Seriously?

Keep digging...

Heliospectra has been doing some good write ups again. I always like their papers. These I think should be read by all.
http://www.heliospectra.com/blog/spectrum-101-absorption-spectra-versus-action-spectra
http://www.heliospectra.com/blog/spectrum-101-action-spectra
http://www.heliospectra.com/blog/what-ask-your-search-best-led-grow-lights

They have more good reads too, if anyone cares to read more...
http://www.heliospectra.com/blog

and that is just heliospectra.

McCree RQE...

Data for it
http://chameleongrowsystems.com/Chameleon_Grow_Systems/Relative_Quantum_Efficiency.html

Or SDS great work...
https://www.rollitup.org/t/photosynthesis-under-solid-state-light-setting-the-standards.833449/

 

[churchhaze]

This is what I used to think as well, but the absorbance curves don't really tell you what it seems like they do.

If a photosystem absorbs a green photon, it will still use it for photosynthesis, it's just less likely the green photon will be absorbed, and more likely to be reflected or transmited.

If you only use red photons, you will reach saturation at canopy level quickly because of how well chlorophyll absorbs red. After this saturation point is where 500-600nm starts becoming useful. It allows you to throw even more power at the plants lower leaves without completely frying the top canopy level.

Seedlings only need R+B because you do not need high intensity levels to penetrate to lower foliage, but 10 foot ganja trees need 500-600nm to cook the middle without frying the top with red.

I'm under the impression that plants do not use 500-600nm, hence why they are green. Would you say 500-600nm is more helpful than harmful for plants or vice-versa?

 

[AquariusPanta]

Seriously?

Keep digging...

and that is just heliospectra.

McCree RQE...
View attachment 3358036
Data for it
http://chameleongrowsystems.com/Chameleon_Grow_Systems/Relative_Quantum_Efficiency.html

Or SDS great work...
https://www.rollitup.org/t/photosynthesis-under-solid-state-light-setting-the-standards.833449/

Have you or anyone you know tried the plasma lights from Chameleon?

I was interested in the idea of a new light source growing my plants but the price scared me away.

 

[AquariusPanta]

This is what I used to think as well, but the absorbance curves doesn't really tell you what it seems like it does.

If a photosystem absorbs a green photon, it will still use it for photosynthesis, it's just less likely the green photon will be absorbed, and more likely to be reflected or transmited.

If you only use red photons, you will reach saturation at canopy level quickly because of how well chlorophyll absorbs red. After this saturation point is where 500-600nm starts becoming useful. It allows you to throw even more power at the plants lower leaves without completely frying the top canopy level.

Seedlings only need R+B because you do not need high intensity levels to penetrate lower foliage, but 10 foot ganja trees need 500-600nm to cook the middle without frying the top with red.

Beautifully explained, Churchhaze.



My head is spinning with the concept you just laid out... wow.



This concept reinforces the practice of not having to use COBs for small herbs and veggies, and instead being able to produce favorable yields with just red and blue as you've stated.

Fuck, nature is wicked!

 

[hyroot]

basically you are all saying the more leaves and height the more green light is needed. Even though the action and absorption spectra and both blogs say plants only absorb a small percentage of green light. So any excess would still be wasted light . I'm seeing links you guys post support what I'm saying and yet you all say the opposite. Maybe I just have to get both cri's and do my own comparison. This will just go around like a broken record.

 

[Greengenes707]

basically you are all saying the more leaves and height the more green light is needed. Even though the action and absorption spectra and both blogs say plants only absorb a small percentage of green light. So any excess would still be wasted light . I'm seeing links you guys post support what I'm saying and yet you all say the opposite. Maybe I just have to get both cri's and do my own comparison. This will just go around like a broken record.

Where does it support your idea of green being wasted, just for clarification.
And do you consider 70% a small amount?

 

[hyroot]

Where does it support your idea of green being wasted, just for clarification.
And do you consider 70% a small amount?

according to action and absorption spectra its about 20-30% any excess beyond that is wasted. If plants are using 70% of green then we should all go back to hps. Abandon led.

 

[Abiqua]

Mr Bolin thank you....Bugbee porn
http://leds.hrt.msu.edu/assets/Meeting/Optimal-spectrum.pdf

 

[churchhaze]

Think of chlorophyll like sunblock. It "protects" the lower foliage from "harmful" red. Almost none will get through the top layer of canopy.

500-600nm has a high chance of penetrating the top canopy layer, and the more layers of leaves there are, the higher chance they'll be absorbed in one of those layers. Everyone wants the penetration of HPS, but penetration means lack of absorbance. That's why HPS has good penetration.

basically you are all saying the more leaves and height the more green light is needed. Even though the action and absorption spectra and both blogs say plants only absorb a small percentage of green light. So any excess would still be wasted light . I'm seeing links you guys post support what I'm saying and yet you all say the opposite. Maybe I just have to get both cri's and do my own comparison. This will just go around like a broken record.

 

[AquariusPanta]

Would you guys consider ~140 watts of COB (~41% light) an act of nuking seedlings at a height of ~24inch, in an area of three square feet? LOL

I'm just wondering why my tomato seedlings looked like shit for the first two weeks LOL.

 

[hyroot]

Think of chlorophyll like sunblock. It "protects" the lower foliage from "harmful" red. Almost none will get through the top layer of canopy.

500-600nm has a high chance of penetrating the top canopy layer, and the more layers of leaves there are, the higher chance they'll be absorbed in one of those layers. Everyone wants the penetration of HPS, but penetration means lack of absorbance. That's why HPS has good penetration.

I understand shade avoidance. I just find it funny that plants all of a sudden absorb 70% green light. Other than heliospectra. I can't find a single study that concurs with that. Heliospectra is quoting from 1972 even though more recent studies in 2006 seem to say much different. Plants absorb and reflect green light therefore only absorb a small amount of green light

 

[AquariusPanta]

Even though the absorption exchange for 500-600nm spectra is low for plants, the amount that passes through the canopies, from a Vero COB, is large enough to be collectively consumed by the plant tissues as the green light penetrates down to the soil.

This is based on my understanding of Church's concept. It doesn't mean that green light is the best but simply that the plants we grow are happy eating blue and red skittles at the top tier while the lower tiers can chew on the leftovers, which a majority turn out to be green skittles. Skittles are skittles though and despite preference, all skittles are worth eating.

 

[doctorflux]

I just find it funny that plants all of a sudden absorb 70% green light.

Look at it this way - you could easily have a dark green leaf show absorption of 90% across 400-700, however within that range absorption in 500-600 might be 70%, giving the leaf a dark green appearance. Just because plants absorb less green light doesn't mean they are highly reflective in the green region.

 

[Greengenes707]

Please read the first one again and at least the second.
https://www.rollitup.org/t/photosynthesis-under-solid-state-light-setting-the-standards.833449/
https://www.rollitup.org/t/cxa-3000k-80-vs-93-cri-an-estimation.833171/

More good reads...
https://www.rollitup.org/t/cree-cxa-3000k-80cri-spectrum-analysis.832666/
http://plantsinaction.science.uq.edu.au/edition1/?q=content/1-2-2-chlorophyll-absorption-and-photosynthetic-action-spectra
http://biology.mcgill.ca/Phytotron/LightWkshp1994/1.5 Bugbee/Bugbee text.htm
Shows lower, but by no means wasted
http://www.bio21.bas.bg/ipp/gapbfiles/v-26/00_1-2_58-69.pdf

Please cite any scientific study where cri trumps photon count...or is even used in any way for that matter. Quanta is what matters and what has always been scientifically accepted. Also accepted is the RQE for majority of species. Not the absorption peaks.

 

[ReeferDance]

CRI is the sh

Even though the absorption exchange for 500-600nm spectra is low for plants, the amount that passes through the canopies, from a Vero COB, is large enough to be collectively consumed by the plant tissues as the green light penetrates down to the soil.

This is based on my understanding of Church's concept. It doesn't mean that green light is the best but simply that the plants we grow are happy eating blue and red skittles at the top tier while the lower tiers can chew on the leftovers, which a majority turn out to be green skittles. Skittles are skittles though and despite preference, all skittles are worth eating.

Did anyone notice those fuckers at skittles changed the green ones to Green Apple from Lime.

WHAT THE FUCK IS THAT SHIT.

Sorry AP.....the wound is still fresh......

But anyway. Just read the last two pages and damn, heliospectra just gave me a green boner.

 

[hyroot]

Please read the first one again and at least the second.
https://www.rollitup.org/t/photosynthesis-under-solid-state-light-setting-the-standards.833449/
https://www.rollitup.org/t/cxa-3000k-80-vs-93-cri-an-estimation.833171/

More good reads...
https://www.rollitup.org/t/cree-cxa-3000k-80cri-spectrum-analysis.832666/
http://plantsinaction.science.uq.edu.au/edition1/?q=content/1-2-2-chlorophyll-absorption-and-photosynthetic-action-spectra
http://biology.mcgill.ca/Phytotron/LightWkshp1994/1.5 Bugbee/Bugbee text.htm
Shows lower, but by no means wasted
http://www.bio21.bas.bg/ipp/gapbfiles/v-26/00_1-2_58-69.pdf

Please cite any scientific study where cri trumps photon count...or is even used in any way for that matter. Quanta is what matters and what has always been scientifically accepted. Also accepted is the RQE for majority of species. Not the absorption peaks.

please cite a study where photon count trumps cri. Not just absorption rates of algae.

with cri I base it off first hand experience. The Inda gros with lower par and higher cri are outperforming lights with higher par and lower cri.

ironically not one person here has tried growing with higher cri. On paper can be very different from real world applications and we all know that.

I just read 2 of.those studies and neither of them say anything about large amounts of green being absorbed.