A Theory: Using Infrared Light to Drastically Reduce Dark Time of Flowering Plants

So I have a little theory, not exactly sure if it will work so hopefully someone with more expertise on the area can confirm if the theory is sound. +Rep for any insightful conversation for sure. For those of you whom this is not your area of expertise, you are probably going to want to know what the hormone Phytochrome is. Photochrome is responsible for the flowering of marijuana plants.

So my theory is infrared light can be used instead of dark periods during flower. My logic is as follows:
The following statements are true:
-Flowering of a plant is controlled by the ratio of the two isoforms of Photochrome.
-Pr converts to Pfr in the presence of red light, and Pfr converts to Pr in the absence of red light.
-A high level of Pr causes plants to flower.
-Pfr also converts to Pr in the presence of far-red light or infrared light.
-The process of Pfr converting to Pr in the dark is slow.


Using flimsy deductive logic I come to the following conclusion:
-The presence of light causes the hormone photochrome to change between it's two isoforms much more rapidly than the total absence of light.
-Infrared light can be used in conjunction with the absence of visual light to greatly reduce the necessary dark time for the plant.

Here is why this is intriguing. If you could flower non-auto-flower plants under 18(HPS)/6(Infrared) you would be giving your plants 50% more light. More light equals more yield. Getting more yield per plant is very very important to a lot of us legal growers who grow under silly plant restrictions. Since you are quickly raising the Pr to the 'critical point' each night and letting it sit there for 6 hours, the plant is spending just as much time with the Pr beyond the 'critical point' as a plant in nature, maybe even longer. In natural total dark settings it takes the plant 10-12 hours to reach that critical point. It varies strain to strain, but every strain needs at least 10-12 hours of darkness to flower.

One problem is I don't know much about infrared. I know it has uses in photography, and there are such things as infrared LEDs. Infrared LEDs appear to give off a lot of visible light, and I thought infrared was invisible to the naked eye. In order for this to have any hope of working I'd imagine the light would have to be only far-red light and absolutely no red light.

So anybody with a good understanding of plant biology out there. Is this theory sound? It looks good to me! But I by no means have a degree in horticulture or biology. Anybody know where I can get some good infrared lights to give this a shot? Unless someone much smarter than I comes along and pisses in my corn flakes, I don't see why I shouldn't give this a shot, small scale. Kinda broke right now, but hopefully one day in the near future I can afford to set up 2 small side by side grow cabs. One cab, one plant. 150 watt HPS each, one plant gets the traditional 12/12, the other 18/6 with infrared. Should be a pretty straight-forward experiment.

So what's everyone think? +Rep for anyone who brings anything interesting to the table.

I have brought the question of adding infared, or ultraviolet light during 'lights' off.

I think I found that uv light increased resin content (producing resin to protect the plant from the uv)

I thought it would work, as its not what the plant considers daylight.. but I never could test.

I posed this question like a year ago, didn't receive any definitive info. & never saw someone do it


Sorry I don't have more info but figured id chime in

I really like what you've come up with on that, and my non-chemist mind doesn't find anything illogical

One thing I wonder though is where the benefit is coming from?

Infrared is lower than 300nm, and your photosynthesis peaks are happening around the 400's. Is there a benefit linked to IR that I'm not aware of?

Verde it's nice to see someone at least thinking along the same lines. +Rep

Gobbly the benefit is being able to keep your lights on longer. If you can accomplish in 6 hours of dark what normally takes 12 you can keep your lights on another 6 hours. Plants do most of their growing during the day. So in theory your plants should grow larger. For example take a strain that flowers under 18 hours of light (auto-flower strains). If you grow one under 18hrs of light and one under 12hrs the one under 18 hrs will be much much larger. So the benefit would be allowing you to grow every strain under 18 (maybe 18+) hours of light.

Here is some solid information on the topic: http://www.chrysanthemumsvancouver.com/photoperiodic.php

This is about mums, not cannabis but the information is what's important.

As I stared at the photochemical reactions that I described above, another possibility occurred to me:

Why not just give the plants a shot of FR light after sunset? If you look at the inter-conversion of PR and PFR in Table1 above, you will see that, in view of the experimental evidence in Table 2, with as little as a one minute exposure to FR radiation one can very quickly convert a significant amount of PFR that has formed during the day back into PR. The irradiated plants should be thus fooled into thinking that they have already had a long night.

Unfortunately, there appears to be no inexpensive commercially available light bulb to do this with, and filters that cut out the red and transmit the FR are not readily available. However, if you look at Figure 2, you will note the way that the light becomes rich in FR radiation (relative to RED) when it passes through a canopy of leaves. The ratio of FR radiation at 730 nm to radiation at 660 nm changes from about 1:1 to about 40:1. A layer of leaves provides an excellent filter that removes red light at 660nm while transmitting FR light at 730 nm. Noting that the conversion between PR and PFR is extremely rapid, removing one molecule of PFR with each absorbed photon. I decided to cover the front of a spotlight with leaves, and simply walk it around the plants spending about 1 second over a given set of plants. I have tested the system with a spectrometer, and found that with a layer of 3 leaves, almost no red light comes through, and the FR is only slightly diminished. The physical arrangement has a 75 watt flood light placed in a glass container (a pyrex coffee pot in my case) with darkened (spray painted) sides. Plastic containers are useless for this purpose since they all soften and collapse in a few minutes). The leaves were held between two layers of chicken wire and pressed against the bottom of the glass vessel containing the floodlight. Rhubarb leaves were ideal for this purpose because of their size.

In 2006, I applied 20 seconds of FR to 70 early and late blooming cultivars for 2 weeks starting the FR radiation on about June 26. When compared with plants that received no extra FR radiation, the irradiated plants showed no observable effect. I thought that perhaps the natural trigger of shortening days that occurred between June 21 and 26 was sufficient and hence my treatment had little effect.

In 2007,I began irradiating half of the earlies and half of the lates on the 14th of June, stopping on July 26. As in the previous year I could see no difference between the controls and the irradiated plants. It was at this point that I discovered a reference to earlier attempts to observe an effect of FR radiation on the blooming of chrysanthemums. The conclusion of those studies were the same as mine, i.e. no effect. H. A. Borthwick; H. M. Cathey (1962).

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Hope this helps.

Gobbly the idea is that (my uv idea) plants produce resin (potentcy) when exposed to UV light in an attempt to shield the plant. Same reason you want low humidity in a flower room.

Sr. Verde said:

Gobbly the idea is that (my uv idea) plants produce resin (potentcy) when exposed to UV light in an attempt to shield the plant. Same reason you want low humidity in a flower room.

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All my research has led me to believe that it works and I have applied it to my grow using a UVB cfl bulb that doesn't emit much heat.

ok, I see what I was missing, the ir is speeding up the conversion. wasn't seeing the link to ir and increasing usable lights, but yeah, that makes sense. As I said before, don't see any flaws in logic. This is really something that should be tested, go for it! Post pics/results, would love to see!

very interesting, i'll be following

Hey kids, I may be a noob on this forum but have over thirty years "in the game". I was a senior member on the greatest grow forum of all time, The OG, or overgrow.com . The og was shut down by the DEA in 04 or 05ish. This subject was covered a few times that I can remember.
Let me ask a few questions... Are you trying to increase yields, or decrease flowering times, or both? Because I have experience with extending light hours, 36 on 12 off, 24/12, 30/12, etc. And I can report that I saw no increase in yield, only an increased electrical bill.
Also let me ask where you learned that IR light induces a girl to produce the flowering hormone faster than simple darkness?
You can buy high quality IR filters, I used them in conjunction with my night vision goggles. Try googling simons smokehouse, if joe pike still works there he will help you out. I got a high quality filter for about $ 150.00 us.
I do have a background/deg ree in biology/horticulture and my opinion is that you will see no gains, though there are many ways to add to yield per plant that are proven to work, if you give me some info on your setup I'll be happy to suggest some things.
I would be happy to elaborate if you would like, and by all means please keep seeking more opinions.

PEACE

gobbly said:

I really like what you've come up with on that, and my non-chemist mind doesn't find anything illogical

One thing I wonder though is where the benefit is coming from?

Infrared is lower than 300nm, and your photosynthesis peaks are happening around the 400's. Is there a benefit linked to IR that I'm not aware of?

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UV is 400's below, IR starts after far red 660's making IR in bout the 700's.

Also, if you decide to test this you might check out the post 10/10 therory ill link ina sec. But they guy is going to try to trick a plant onto a 20hr day. If both ideas work you might be able to seriously decrease the overall time of flowering. Another thing is an 18 hr day 6/12. a flowering plant only needs 6 hours of light before going into dark. if you could put it on a 18 hr day then reduce the dark by half (12 hr total) you would finish a avg 9wk in 4.5 and the dreaded haze crosses in 6 max. GL if you attempt to test these.

Using any colored light other then green during the night cycle will cause photosynthesis. Doing so during the night cycle will force hermy your plant.

This won't work and its quite obvious you could have just read about all the people whos plants hermy from the single red light on a power strip or another object.

this has actually been researched and tested before, on here even. when i was searching uvb i believe i found the thread. in the thread they are using uvb reptile lights to extend flowering times to i think 15 or 16 hour days. the technique has enough merit that it will be incorporated into the updated growers bible. uvb lights also act as MH mh lights in flower in that they also increase resin production. they are more than just play around with and observe. Too much uvb light will hurt the plants, to little with the long flower hours and it will reveg. if you are in your grow room with the uvb bulb on try to dodge the skin cancer, and close your eyes.

try a google search for uvb +rollitup

Dystopian said:

UV is 400's below, IR starts after far red 660's making IR in bout the 700's.

Also, if you decide to test this you might check out the post 10/10 therory ill link ina sec. But they guy is going to try to trick a plant onto a 20hr day. If both ideas work you might be able to seriously decrease the overall time of flowering. Another thing is an 18 hr day 6/12. a flowering plant only needs 6 hours of light before going into dark. if you could put it on a 18 hr day then reduce the dark by half (12 hr total) you would finish a avg 9wk in 4.5 and the dreaded haze crosses in 6 max. GL if you attempt to test these.

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yeah, sorry, that was a typo. I meant to say below 300mm (micrometers) with photosynthesis happening in nm. Point was they are different spectra, but as I mentioned subsequently, I was missing the link from ir to increased pr, anyway, disregard my comments which have already been addressed

blackguy said:

Using any colored light other then green during the night cycle will cause photosynthesis. Doing so during the night cycle will force hermy your plant.

This won't work and its quite obvious you could have just read about all the people whos plants hermy from the single red light on a power strip or another object.

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Umm, the moon reflects light, blue light to be exact, which doesnt seem to mess the flower cycle. Also some outdoor growers "spray" their flowers with red LED light then spray them again with blue. by doing this they shorten the time from veg to flower(red) and undo the damage they might have been caused to the flower cycle by the red (blue) I dont think that just because it is almost 2011 and we, mankind, having thought of everything already can just dismiss something new. Really, how long have we been growing inside at most (absolutely not) the last 50 years? I refuse to think we have tried everything.

Dystopian said:

Umm, the moon reflects light, blue light to be exact, which doesnt seem to mess the flower cycle. Also some outdoor growers "spray" their flowers with red LED light then spray them again with blue. by doing this they shorten the time from veg to flower(red) and undo the damage they might have been caused to the flower cycle by the red (blue) I dont think that just because it is almost 2011 and we, mankind, having thought of everything already can just dismiss something new. Really, how long have we been growing inside at most (absolutely not) the last 50 years? I refuse to think we have tried everything.

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Testing on this dates back to before the 60s.

phyzix said:

Testing on this dates back to before the 60s.

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Not exactly what i said but alright... The lightbulb as we know it was not made until appx 1910, 110 yrs after the first one(fast eh?). In the 1920's less than 10% of british homes had electricity. It wasnt until mid 1930's that FDR (fruit) said that electricity was no longer a commodity, even tho many Americans were still without. Even so i dont think people really moved inside to grow unless there was a reason: 1937 MJ Tax stamp. But was it possible? with incandescents? The first viable fluorescent light wasnt sold until 1938. Theoretically after this point ppl could then grow indoors, however unlikely, which is what i was getting at. But I really doubt that research kicked off just as soon as it was outlawed and became the subject of governmental funding. The only way to emit only IR light, that i know of, is with an LED and the first IR LED was patented in 1961.

Who studied this? you dont say. When did study on this start? you dont say?

Dystopian said:

Not exactly what i said but alright... The lightbulb as we know it was not made until appx 1910, 110 yrs after the first one(fast eh?). In the 1920's less than 10% of british homes had electricity. It wasnt until mid 1930's that FDR (fruit) said that electricity was no longer a commodity, even tho many Americans were still without. Even so i dont think people really moved inside to grow unless there was a reason: 1937 MJ Tax stamp. But was it possible? with incandescents? The first viable fluorescent light wasnt sold until 1938. Theoretically after this point ppl could then grow indoors, however unlikely, which is what i was getting at. But I really doubt that research kicked off just as soon as it was outlawed and became the subject of governmental funding. The only way to emit only IR light, that i know of, is with an LED and the first IR LED was patented in 1961.

Who studied this? you dont say. When did study on this start? you dont say?

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Cathey, H.M. and H.A. Borthwick. (1957). Photoreversibility of floral initiation in chrysanthemum.

Borthwick, H.A. and H.M. Cathey. (1962). Role of phytochrome in control of flowering of chrysanthemum.

Cathey, H.M. and H.A. Borthwick. (1964). Significance of dark reversion of phytochrome in flowering of Crysanthemum morifolium.

Cathey, H.M. and H.A. Borthwick. (1970). Photoreactions controlling flowering of Crysanthemum morifolium (Ramat. & Hems.) illuminated with fluorescent lamps.

the '57 study was red and far red not infrared (atleast thats all i have been able to read) which doesnt even matter because my point was absolutely missed. your web posting just confirms what this guy is asking. yet, you wanna look smart over 3 years? well if being told your right makes your day Merry Christmas! Your right there? you havent really said nething to make you right but i think, nay, believe you are right. Have a nice day.