The far red thread

captainmorgan

Well-Known Member
depends on the lighting..

with 730's the led side in my grow is finishing faster. My induction side is taking longer

@captainmorgan I hypothesized that before in your thread. When I said mine seem to take longer and yours finished faster. So the light source does make a difference in finishing times. I'm anxious to try with more cobs.
Do you have a spectral graph of the Indagro light? If I remember right it's around 4750k from talking with Darryl. Maybe less deep red?
 

captainmorgan

Well-Known Member
I became aware of the Phytochrome trigger around three years ago or more here on RIU by reading a thread from a guy that went by the handle Splifferous. He was using one of GLS's 730 nm lights on a outdoor plant. My interest was in increasing yield but the faster flower time was nice too. 730 nm is what transitions our favorite plant from one phytochrome state to the other,in easier terms from day to night. That's why outdoors flowering can start at 14 hours and indoors you use 12 hours. Without the natural 730 nm of outdoors a indoor plant takes two hours to switch states,it needs 660 nm to transition back at lights on indoors. So by using 730 at lights out indoors you eliminate the two hour transition and by doing so,you can increase your lighting schedule up to 14/10. With the extra two hours of light your plants can store more energy to grow with,thus the increased yield.

This might help understanding the advantages. Indoors at 12/12 without 730 the plant thinks it's 12/10. With 730 at 14/10 the plant thinks 14/10,our plants flowering is controlled by the length of darkness not the amount of light.
 
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hyroot

Well-Known Member
Do you have a spectral graph of the Indagro light? If I remember right it's around 4750k from talking with Darryl. Maybe less deep red?
These are the spd's I got from @Greengenes707 . He had the ig tested or what ever

no pontoon
no pontoon.jpg

with pontoon

Scan 2014-7-20 0002-32.jpg



yeah less deep red than the white leds. I wonder if adding 3k or 4k cobs between each inda gro would make any change to finishing times. It would probably improve yield though.
 

captainmorgan

Well-Known Member
These are the spd's I got from @Greengenes707 . He had the ig tested or what ever

no pontoon
View attachment 3395665

with pontoon

View attachment 3395666



yeah less deep red than the white leds. I wonder if adding 3k or 4k cobs between each inda gro would make any change to finishing times. It would probably improve yield though.

Yea I really wanted to play with the Emerson Effect but could never find 680 nm,wonder if it's available now?
 

mc130p

Well-Known Member

Rahz

Well-Known Member
White LEDs have some 680 nm in them. About 30% relative to peak spectrum output with CXB 3000Ks, 60% at 90 CRI... so the 730 should be all that's needed to get the Emerson effect.

So as far as the phytochrome response there has to be a period when 730 is the only spectrum? Cause I'm wondering for those who use HPS and already have far red in the spectrum, they still need a 12/12 so there would still need to be a 730nm only period?
 

captainmorgan

Well-Known Member
White LEDs have some 680 nm in them. About 30% relative to peak spectrum output with CXB 3000Ks, 60% at 90 CRI... so the 730 should be all that's needed to get the Emerson effect.

So as far as the phytochrome response there has to be a period when 730 is the only spectrum? Cause I'm wondering for those who use HPS and already have far red in the spectrum, they still need a 12/12 so there would still need to be a 730nm only period?
Yea most indoor lighting doesn't have any 730,plus if 660 is present at the same time it cancels it out,730 is present after sunset.

From my understanding 680 is the sweet spot for Emerson.
 
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Rahz

Well-Known Member
So to get the Emerson effect and the phytochrome response you would have deep red running on a separate timer that stays on for a few minutes longer.

I think though that it would take more than a token amount of far red to achieve a decent Emerson effect right? I'm wondering it it's worth doing with LED. In the first post I mentioned the 20w arrays, about $20 each.

Maybe 5-10% or 5-10 watts per 100 of white light?
 

captainmorgan

Well-Known Member
So to get the Emerson effect and the phytochrome response you would have deep red running on a separate timer that stays on for a few minutes longer.
Sorry but I just smoked a bowl of GG#4 so I may ramble. The two are separate things,the Emerson has to do with a chlorophyll peak and photosynthesis during lights on and the Phytochrome State is like a on/off switch from light to dark.
 

Rahz

Well-Known Member
Exactly, I should have been more clear. The far red would run all day and stay on a few minutes longer than the white. That would achieve both the Emerson effect and the phytochrome response correct?

The easiest solution would be two digital outlet timers so they could be synced up properly?
 

ttystikk

Well-Known Member
I became aware of the Phytochrome trigger around three years ago or more here on RIU by reading a thread from a guy that went by the handle Splifferous. He was using one of GLS's 730 nm lights on a outdoor plant. My interest was in increasing yield but the faster flower time was nice too. 730 nm is what transitions our favorite plant from one phytochrome state to the other,in easier terms from day to night. That's why outdoors flowering can start at 14 hours and indoors you use 12 hours. Without the natural 730 nm of outdoors a indoor plant takes two hours to switch states,it needs 660 nm to transition back at lights on indoors. So by using 730 at lights out indoors you eliminate the two hour transition and by doing so,you can increase your lighting schedule up to 14/10. With the extra two hours of light your plants can store more energy to grow with,thus the increased yield.

This might help understanding the advantages. Indoors at 12/12 without 730 the plant thinks it's 12/10. With 730 at 14/10 the plant thinks 14/10,our plants flowering is controlled by the length of darkness not the amount of light.
This is intriguing, if true and can be proven/replicated. Have you?
 

PSUAGRO.

Well-Known Member
@Psuagro are you saying that you use a halogen bulb to get the same effect at lights out? If so what wattage for what size space. I have read of this and it definitely sounds cheaper than using expensive LEDs. Any negative effects of halogen?
As a trigger I see no problem using a halogen bulb, it's use is nothing new(greenhouses). Obviously a monochromatic 730nm emitter will be way more efficient, but your only running it for minutes.
 
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alesh

Well-Known Member
As a trigger I see no problem using a halogen bulb, it's use is nothing new(greenhouses). Obviously a monochromatic 730nm emitter will be way more efficient, but your only running it for minutes.
And does a halogen bulb work equally well as 730nm emitter? Besides IR it obviously produces some visible light. Does it matter? Just asking -- I've got no experience with neither far red LED nor halogen bulbs.
 

PSUAGRO.

Well-Known Member
And does a halogen bulb work equally well as 730nm emitter? Besides IR it obviously produces some visible light. Does it matter? Just asking -- I've got no experience with neither far red LED nor halogen bulbs.
probably not, honestly i'm not sure alesh. I'ts use commercially makes me think that it is effective even with the visible light. Never tried them myself though

with the IG pontoon, high temps and 730nm was a training nightmare in my experience. you need to keep your temps absolutely in check with the trigger IMO.
 

Doer

Well-Known Member
So to get the Emerson effect and the phytochrome response you would have deep red running on a separate timer that stays on for a few minutes longer.

I think though that it would take more than a token amount of far red to achieve a decent Emerson effect right? I'm wondering it it's worth doing with LED. In the first post I mentioned the 20w arrays, about $20 each.

Maybe 5-10% or 5-10 watts per 100 of white light?
http://en.wikipedia.org/wiki/Emerson_effect
The Emerson effect is the increase in the rate of photosynthesis after chloroplasts are exposed to light of wavelength 670 nm (far red light) and 700 nm (red light). When simultaneously exposed to light of both wavelengths, the rate of photosynthesis is far higher than the sum of the red light and far red light photosynthesis rates.
 

Doer

Well-Known Member
probably not, honestly i'm not sure alesh. I'ts use commercially makes me think that it is effective even with the visible light. Never tried them myself though

with the IG pontoon, high temps and 730nm was a training nightmare in my experience. you need to keep your temps absolutely in check with the trigger IMO.
You mention, I look up, I get ideas.

Pontoons are run from batteries!! That is the timer. Brilliant.
 
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