Trichomes, THC and UVB light.....

Thanks bro! Good info from you as usual!

Mmmmm canabutter!

just got my uvb 10 flourescent bulb. 18 watt, about a foot and a half long. Paid 20 bucks for it. Can wait till day time in the tents!

also I am aware of various uvb bulbs for various stages of growth. I read about this a long time ago and am now just getting my bubls going. The cfl bulb at the pet shop was like 50 bucks but the flouro tubes were cheap and I see from a quick check very low watts at only 18 watts. Lol. 300! watts i saw in a post.

I have a lot of reading to do and this is my day off. But if someone has any words about the uvb in veg, I would love to hear. Is a 5 good? I also saw some uva chap cfls and other sun spectrum bulbs. Along with using meotorite dust as a soil amendment I would like to read up on that. I wish I had a wharehouse to experiment with tools. Volunteer at Monsanto maybe, but I am high!


i just read this, I am sure it is in the thread, long!, also quarts glass will let some uvb thru i found. Also has anybody ever got huge huge!!!!!! headaches from an unglassed MH? I am awating my cool tube for a 400 mh and ow,everytime I look at it I am piundedwith migraines. Sunglasses barely help.

The writer's own experience allow for a more specific conclusion: If the UVB photon is missing from the light stream(a), or the intensity as expressed in µW/cm2 falls below a certain level(b), the phytochemical process will not be completely energized with only UVA photons which are more penetrating but less energetic, and the harvested resin spheres will have mostly precursor compounds and not fully realized THC(c).

(a)Examples of an environment where the UVB photon would be missing from the light stream include all indoor cultivation illuminated by HID bulbs and in glass or corrugated fiberglass covered greenhouses.

thanks everyone for their great contributions. I will remain wholly interested in the outcome of some of these efforts.

I went through that paper that should have paid attention to the the title - review - which is exactly what it was - as review of much of the stuff already discussed in this thread.

In other efforts, I also came across another thread that talked about 2.0 and 5.0 and the coming of 10.0 bulbs from petsmart (http://www.petsmart.com/product/index.jsp?productId=2752556). With the posts here, I am thinking the 10.0 bulbs will be measurably beneficial. I think I am going to try that.

well after some additional reaching and reading I have gone with 2 x 160W SolarGlo from Hagen. I will add that to my bbox measuring 3x3x4 with a 400W HPS. Could be interesting. I really should get a UV meter? I'll be putting up a new grow journal very soon. Tahoe's TGA + HPS + UVB =

bump want pictures!! lol

journal is up and running

2 x 160W uvb lights on full eight hours within twelve-twelve. Did a run up 2 -4 -6 -8 hours to monitor any ill effects. none seen so have stuck with the current schedule.

I'm liking the results but we'll have to see how things develop over time. Check it out!

https://www.rollitup.org/grow-journals/205665-tahoes-tga-hps-uvb-co2.html

Great topic. I just wish the thread wasn't so cluttered.

Anyway, if supplying some UVB light increases potency that would be awesome. However, I find the logic behind the idea less than convincing. First, the fact that more potent plants come from regions with greater UVB doesn't necessarily prove anything. Is UVB also responsible for the exceptional flavor of Chilean sea bass? No, it's because that species of tooth fish is only found off the coast of Chile. In general conditions in equatorial regions are better for just about all living things. It is possible that there is a causal relationship here but it's merely a possibility at this stage and the greater potency could be the result of a myriad of other things.

Also, UV light is an extremely poor penetrator so it is unlikely that the plant needs any additional substance to filter it. Even a piece of plastic wrap will filter UV light. Plus, all all UV light is harmful. Of course C is more harmful than B which is more harmful than A. Also when it comes to penetration the opposite is true - A penetrates the most followed by B and lastly C.

Even if THC is produced to filter UVB light, isn't it also possible that the THC is destroyed in doing so? We do know that UV light destroys THC in the long run so it's also possible that the degradation meets or exceeds the increase in production. Then again harvest timing may be the crucial factor.

In the end a proper experiment needs to be conducted and the product analyzed in a lab in order to know for sure. In the mean while I'm going to finish my girls with my full spectrum MH bulb as growth has pretty much stopped. You never know.

Dude, alot of testing has been done through the last decade or so.. The most recent question around here is what the most effective way to get it is..
You basicly rattled off the physics that account for the presumed reason that this is the case, but you used them to come to the opposite conclusion..
And yes plastic would work fine, but plants never really seemed to evolve to the point of building greenhouses..
Light is involved in production, and destruction of various cannabinoids.. UV light shifts that equilibrium more to production via increased trichome/resin production while the plant is actively maturing.. Trichromes are like pawns to a plant.. They're the first line of defense..
But then again, sharks never stop swimming so who knows..

born2killspam said:

Dude, alot of testing has been done through the last decade or so.. The most recent question around here is what the most effective way to get it is..
You basicly rattled off the physics that account for the presumed reason that this is the case, but you used them to come to the opposite conclusion..
And yes plastic would work fine, but plants never really seemed to evolve to the point of building greenhouses..
Light is involved in production, and destruction of various cannabinoids.. UV light shifts that equilibrium more to production via increased trichome/resin production while the plant is actively maturing.. Trichromes are like pawns to a plant.. They're the first line of defense..
But then again, sharks never stop swimming so who knows..

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The seed is already protected by the the calyx which contains chlorophyll. Generally anything that contains chlorophyll is a component of photosynthesis. It would be counter productive to block light from any part of the plant that carries out photosynthesis so it stands to reason that the roll of the trichome is not to block light. As stated it wouldn't even be necessary because UV is so poor at penetrating anything.

I'm just pointing out a number of reasons why the hypothesis might not be sound - that's what science is all about.

Anyway, if a great deal of research has been done, can you tell me where to find it?

I am looking for actual scientific data, not some growers opinion.

You mentioned UVB is easily filtered by trichromes.. Thats kind of the point visible and especially red light passes more easily.. They also help with flower hold moisture btw, and dryer climates tend to produce more potent weed..

born2killspam said:

You mentioned UVB is easily filtered by trichromes.. Thats kind of the point visible and especially red light passes more easily.. They also help with flower hold moisture btw, and dryer climates tend to produce more potent weed..

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The tissue of the seed calyx should be sufficient to filter UV light. Also, there is a lot of space between trichomes though which light can pass. Plus, there are a whole lot of plants that are capable of similar seed production that produce zero THC.

Look, I don't pretend to know why THC is produced by the plant. All I'm sayng is that the correlation between regions with higher UVB light and high quality weed doesn't necessarily hold water. It may, but it may just be a non-sequitor.

If anyone knows of any scientific studies in this area by all means post a link.

hey there folks ..... nice to see the thread alive and well again. I guess I have a couple of thoughts that come from this last round above. I had a substantial folder of background material that disappeared with my last hard drive. I have slowly been pulling together all those that I can find. I have not gone back through this thread but I would have sworn that I made reference to stuff along the way. And it is also my recollection that the discussion was as said above, not about whether or not there was increased trichome and thc production with higher incidence of uv light, it was a discussion about how and why the biology, the physics, the whatever? I suppose it was one of the underlying thread assumptions that it had been shown with reasonable certainty that the addition of uv light to an indoor grow improved the results - yield improved, but to a lessor extent than quality-potency).

I also believe that there was a component of this discussion that revolved around the shortcomings of indoor growing. It was not only the argument that pot from equatorial regions which measurably receive the greatest uv intensity was greatest among pot strains. With the advancement in lighting and metrics, the thought of "what's missing" what can we do to "mimic" sunlight more closely? this is based on the observed results that people achieve with indoor and outdoor grows. It is a belief held by me that outdoor pot given the same due care and attention indoor growing receives but with the sun's real energy, the monsters you can grow are out of this world. So there really were multiple drivers behind seeking a better understanding of the relationship between uv and thc/trichome.

That is not to say that that assumption to preface our discussion was valid. Those of us who were the initiators of this thread were believers of the assumption, so for us it was valid.

In response to a comment about the thread being "cluttered" .... I guess that just a clear representation of the commotion going on from my neck up .... hahahahaha! and for that reason, the closest I will get to doing a proper experiment (remember, I am only a scientist of 30 years) is what I am doing now. Same seed batch, same strain, same growing conditions (mostly), same love and care, ADDED UVB light. Comparing the same seed same strain at day 44 showed the obvious difference between the two grows ...... they are barely recognized as the same .... but I am the first to acknowledge that there are many many factorz, that influence the result of what you see. For me, the answer is this; I believe that to grow indoors, it is beneficial to make attempts to improve the "quality" of that indoor environment. We all make great efforts in this regard. In my case, I also believe supplemental CO2 up to 1600ppm is beneficial. I realize that these "new" conditions require adjustments in water and food and other parameters. Similarly, I believe adding uv light is "improving" the quality of my environment. and with a sample size of one as my current experience, we'll have to wait and see what the measured results (wet/dry weight) will be. But even with that .... this is still one grow, one event ,and the next one and the next one and the next will each be different. Based on what I have seen so far with this grow, I'll very likely be including the uv lights into my successive grows ........ walking on!!~~

You can't compare two plants from different seeds. There are typically vast differences to begin with when growing from seed. The only way to do this experiment properly would be to use clones or better yet only expose a portion of one plant to the UVB. Also, you would have to increase the lumens equally using a non-UVB source for the control plant. Also, you would need to have access to a lab to do a legit quantitative measure of actual TCH. If you are a scientist of 20 years you ought to have some basic understanding of scientific methods and criteria. No offense but your anecdotes are far from scientific.

I appreciate the thought you have put into your reply. Your description of a potential research direction is helpful in allowing me to understand your perspective. However, I believe we might not be talking on the same page. With all due respect, I can compare whatever I like. The question is whether the comparison is meaningful or not. And whether or not it is meaningful is a function of the expectation of the exercise. If I were interested in conducting an appropriately designed and executed research project with sufficient scientific rigor to withstand full peer review, then I would do so. However, that is not my intent or expectation. And I expect if I were to choose such a path for research, that path would not be on an internet forum that has limited academia connections.

tahoe58 said:

I appreciate the thought you have put into your reply. Your description of a potential research direction is helpful in allowing me to understand your perspective. However, I believe we might not be talking on the same page. With all due respect, I can compare whatever I like. The question is whether the comparison is meaningful or not. And whether or not it is meaningful is a function of the expectation of the exercise. If I were interested in conducting an appropriately designed and executed research project with sufficient scientific rigor to withstand full peer review, then I would do so. However, that is not my intent or expectation. And I expect if I were to choose such a path for research, that path would not be on an internet forum that has limited academia connections.

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So in other words there is no solid evidence to support the UVB hypothesis. Maybe some day someone will try a lizzard light over 1 clone compared to a similar clone without and do a single blind with some friends.

At any rate, the Hortilux blue lamps put out gobs of light in the UVB spectrum.

One of the paper's that might be valuable to review is Pate (1994) Chemical Ecology of Cannabis. There is another that is more quantitative but I have to still relocate it. I will pass along again what I do find.

tahoe58 said:

One of the paper's that might be valuable to review is Pate (1994) Chemical Ecology of Cannabis. There is another that is more quantitative but I have to still relocate it. I will pass along again what I do find.

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hey man, if you don't mind me asking, how long are you exposing your plants to UVB everyday? I assume you want a steady increase. and when did you start exposure? and what kind of UVB light are you using? like watts?

hey no worries. I'm using 160W SolarGlo floodlights. I have two. I started with running them two hours then four then six then 8 .... I started them about a week into flower I think? I'd have to go back and check my calender of dates. Another friend of mine had an idea about putting them on a rheostat to infinitely adjust the UVB increasing intensity into noon and then decreasing intensity to night. These bulbs are self ballasted and I'm not sure that would work here. For now. that is how I am doing it. I am quite impressed with the results. But as is the case, there are other factors that influence the bud growth, not the least of which is a different phenotype - but regardless, she is a fine specimen, and I believe that some of that is due to the additional uv energy.

Awesome stuff guys, especially the last 1/2 dozen or so posts.
It's such a pleasure to actually witness an intelligent concersation on this site.
I've been watching this post from the start as I bought some (3 to be exact) reptiglo 10 26W cfl's and have been experimenting for several months, unfortunately most of my notes were on a harddrive sent back for warranty replacement.
keep up the good work.