Far-red: The Forgotten Photon

Thought you all might enjoy this bit of knowledge coming from Apogee Instruments.


Vid Description:
In this video, Dr. Bruce Bugbee reviews recent research on the powerful effect of far-red photons on plant growth and development. The summary includes the evidence for the direct value of far-red photons in photosynthesis as well as their value in promoting leaf expansion rate in lettuce. The evidence indicates that we need to redefine photosynthetic photons to include wavelengths beyond 700 nm. The availability of efficient far-red emitting LEDs means that there are immediate commercial applications of this research for indoor agriculture.

Far red (730nm) should be in everyone's LED setup. Also, try to run infrared (810nm) diodes. It raises the leaf temperature similar to an HPS. You'll end up with strong stems under big buds.

Or just run HPS and not worry about the spectrum, cause it's all included.

T macc said:

Far red (730nm) should be in everyone's LED setup. Also, try to run infrared (810nm) diodes. It raises the leaf temperature similar to an HPS. You'll end up with strong stems under big buds.

Or just run HPS and not worry about the spectrum, cause it's all included.

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First time hearing of 810nm, not far red though - however, this is probably coming from people that are mixing up far red and IR and thinking they are the same terminology. Definitely going to look into that, was literally just thinking of why so many plants are lanky and skinny in grow tents. Thanks

I guess bugbee's students are now running tests on added far red on cannabis. We'll be wiser when he'll have results. Added fr certainly is not neccessary to grow cannabis with white leds.

i2am said:

First time hearing of 810nm, not far red though - however, this is probably coming from people that are mixing up far red and IR and thinking they are the same terminology. Definitely going to look into that, was literally just thinking of why so many plants are lanky and skinny in grow tents. Thanks

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Probably either too many reds to blues in veg, or not enough light due to power or distance. That's my best crack at it.

Love Bruce! Pouring through all his videos now The science geek in me loves it!

HydroKid239 said:

Probably either too many reds to blues in veg, or not enough light due to power or distance. That's my best crack at it.

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All 3 are some of the biggest reasons. This is moreso leaning on what I see with Electric Sky LEDs - but they have 8% of the total light going into their far-red in their wideband spectrum - which as you stated, it seems like too many reds. I knew blue and light distance could cause that, but not red.

T macc said:

Far red (730nm) should be in everyone's LED setup. Also, try to run infrared (810nm) diodes. It raises the leaf temperature similar to an HPS. You'll end up with strong stems under big buds.

Or just run HPS and not worry about the spectrum, cause it's all included.

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‘Where would one find some 810 strips?

bk78 said:

‘Where would one find some 810 strips?

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My mistake. Its 840-870 nm diodes. I didnt use individual strips. I got a supplement board from Rapidled. I'm sure strip can be found. This is one of the supplement boards I have.

660 and 730 is deep red and far red no?

Southernontariogrower said:

660 and 730 is deep red and far red no?

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Wouldn't 840-870 be infa red? So heat no light to speak of.

Southernontariogrower said:

Wouldn't 840-870 be infa red? So heat no light to speak of.

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There is light to be taken in by plants. An increase in flower mass is what I observed. I wouldn't say my tent was a lot hotter, but I also raised my wattage up by 120. So I'd say most heat came from wattage.

I used it one round and have since changed my setup. If I were to get back into a smaller garden, its definitely going back in. Along with my Solacure uvb

Noob question guys but have no idea about lights. What is more important for flowering, low Kelvin for most diodes (3000K) or more farred(or infrareds)diodes? Most led qbs I see have very little red diodes. And the million dollar question: is it possible to build a light with ONLY FAR-REDS(or infrareds, don't know the difference)?

Eugenios said:

Noob question guys but have no idea about lights. What is more important for flowering, low Kelvin for most diodes (3000K) or more farred(or infrareds)diodes? Most led qbs I see have very little red diodes. And the million dollar question: is it possible to build a light with ONLY FAR-REDS(or infrareds, don't know the difference)?

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Most important is the number of par photons it produces as long as the spectrum is reasonable like 2700-4000 kelvin. The added red leds are there to raise efficacy and they are rather expensive... I'd pass on them.

Horselover fat said:

Most important is the number of par photons it produces as long as the spectrum is reasonable like 2700-4000 kelvin. The added red leds are there to raise efficacy and they are rather expensive... I'd pass on them.

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Thanks for the reply bro. Would you kindly tell me or send me a link to know about the difference of farreds and infrareds and how much Kelvin are they? Thanks buddy!

Eugenios said:

Thanks for the reply bro. Would you kindly tell me or send me a link to know about the difference of farreds and infrareds and how much Kelvin are they? Thanks buddy!

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Forget about the reds, far reds and ir. Just get white leds.

Edit: you can add them later if you want to, but they are not needed to grow and will not magically transform a grow.

Eugenios said:

Noob question guys but have no idea about lights. What is more important for flowering, low Kelvin for most diodes (3000K) or more farred(or infrareds)diodes? Most led qbs I see have very little red diodes. And the million dollar question: is it possible to build a light with ONLY FAR-REDS(or infrareds, don't know the difference)?

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I agree with @Horselover fat . White light is what you need. It has all colors of the visible spectrum. You can make a light with just reds, but it'd perform poorly. Ever hear of UFO lights and Marsjunk? The QBs with added red are nice, but even just the standard QB great. As far as Kelvin, you can flower with anything really. Even 10,000k. Blues are for quality and reds are for mass. 2700-4000k is the norm and usual.

I would want very little far-red in a flowering to help cut back on stretch. Some IR LEDs on separate switch or jumper would be nice to help increase leaf temps in winter.

Awesome thanks for all the precious info. Can I also have your opinions on UV strips/bars? Some people here say it increases THC but decreases yield? Probably broscience but want to hear your opinions. God Bless you.

Since cannabis is shade avoidant, wouldn't it suggest that far-red light would stretch the plant? Could you use far-red to promote stronger stems and leaves in coordination with blue light to minimize stretching?