UV Light and Terpenoids

GreenintheThumb · Oct 6, 2009

While we can all agree that Marijuana Optics is a joke, many seem to believe our favorite plant's terpenoid profile can be augmented with UV light. I'm not sure if they think it will actually change the type of terpenoids produced or simply the amount produced but it's certainly an interesting subject of debate.

I seem to recall Sam conducting some UV light trials and claiming to see no discernible effect.

Didn't Felix try some high altitude gardens as well? Not sure what he noticed. Anyway, this is the place to put your thoughts on the subject. Lets hear from you.

dank.frank · Oct 6, 2009

I personally believe...the sun has UVB. Our gardens need UVB. It is an element that is in nature that should be in the grow room. It really is that simple.

I use UVB in my room. Does it make a difference...not sure...lol. I honestly don't know...don't care.

Nature has it. I want it too!

dank.Frank

EvilTwin · Oct 6, 2009

Hi Green...
To agree that mj optics is a joke, first I have to understand that reference...mind explaining that?

I watched Marijuana Man's vid on THC and UV-B about a year ago. It made sense and so finally I decided to give it a try. I installed 4 mercury vapor reptile lights along the length of my bloom room and once my plants are out of veg, I'm going to activate the system and see if the results were worth it. I spent about $200 on the project so all is not lost if it doesn't make any difference.

I installed the lights at such a height that it simulates full sunlight UV-B and installed a door switch so the lights will go off whenever I open the door. (eye protection)

I won't have any results till after Christmas but I'll certainly share them.
ET

PS: Hey Frank...what lights are you using for UVB? Did you know that there are MH UVB lights available now too?

amoril · Oct 6, 2009

...and here we go

you'll have to give me a few minutes to dig through my links, so that I can actually cite some evidence for some of the claims.

amoril · Oct 6, 2009

EvilTwin said:
Hi Green...
To agree that mj optics is a joke, first I have to understand that reference...mind explaining that?

I watched Marijuana Man's vid on THC and UV-B about a year ago. It made sense and so finally I decided to give it a try. I installed 4 mercury vapor reptile lights along the length of my bloom room and once my plants are out of veg, I'm going to activate the system and see if the results were worth it. I spent about $200 on the project so all is not lost if it doesn't make any difference.

I installed the lights at such a height that it simulates full sunlight UV-B and installed a door switch so the lights will go off whenever I open the door. (eye protection)

I won't have any results till after Christmas but I'll certainly share them.
ET

Marijuana optics by Joe Knuc. google it, read it, laugh at (most of) it.

unfortunately, the fact is hard to discern from the utter fiction.

-----

the MJMan vid is cool, but he also seems to follow some of the poor logic that is used in the MJ optics article....and he misuses the application of his graphics.

The pics are from a Mahlberg study in '97 (I think), either way, the study actually gives indirect support for the use of UVB, by determining what chemicals are actually able to permeate into the trichome from the rest of the plant matter.....ie, what chemicals a plant can send into a trichome.

indifferent · Oct 6, 2009

Aye, that Joe Knuc article is a joke.

Sam did indeed say that he was unable to find any benefit to UV light, he used UV fluoro tubes in a greenhouse.

Two great points Sam made that folks need to bear in mind:

1. If UV was truly important in the production of resin and potency, then all indoor grown bud would lack resin and potency as fluoros and HIDs don't produce UV.

2. A high altitude cultivar such as a Highland Nepalese will have the same high if grown at sea-level with a lower UV level, the nature of the high and potency being genetically pre-determined.

Apart from the research done by Raphael Mechoulam in Israel where he exposed CBD acids in a petri dish to UV light at 285nm and got a small proportion to convert into THC acids, has anyone ever published any proper scientific work on this subject?

amoril · Oct 6, 2009

ok, Im going to preface my future posts with a general overview of where Im going, so that I can jump around more freely as I find the links Im looking for.....

working in a backwards-logic, sorta....

cannabinoids are, all, terpenophenolics. terpenophenolic is a combination of a terpenoid and a phenol.

terpenoids are aromatic molecules, and in some of my references will be flavanoids, just a specialized terpenoid.

i think thats all I needed to say up front.

------------

first round - UV light boosts flavanoid production as a defense mechanism, flavanoids absorb UV light and protect more vital cells from degradation.

This waveband exerts various actions: suppression of the over-all growth of plants, reducing cell division or elongation; cell damage such as cell collapse and tissue browning; and reduction of biomass production (Caldwell 1971, Tevini and Teramura 1989). Besides, this waveband causes photomorphogenesis, and induces the synthesis of anthocyanin and other flavonoids alone or in coaction with RL absorbed by phytochrome (Beggs et al. 1986). In intact plants flavonoids are synthesized in the epidermis, and serve as a UV-B cut-off filter to the light entering the tissue (Schmelzer et al. 1988, Tevini et al. 1991, Cen and Bornman 1993).

The flavonoid-inducing effect of this waveband is established by action spectra (Fig. 7). They have peaks at ca. 290 nm, differing from the absorption of DNA or RNA, and suggest the occurrence of a particular UV-B photoreceptor. This UV-B action is manifested or enhanced by phytochrome action (Yatsuhashi and Hashimoto 1985), and further enhanced by BL (Drumm and Mohr 1978, Duell-Pfaff and Wellmann 1982). That the flavonoid induction by UV-B really occurs in the natural growing conditions was shown by the effects of UV-B supplements to artificial WL (Adamse and Britz 1992, Arakawa et al. 1985, Maekawa et al. 1980, Cen and Bornman 990) and supplement to sunlight (Flint et al. 1985). The findings that UV-B elimination from sunlight greatly reduced anthocyanin synthesis in rose flowers and eggplant fruits (Mihara et al. 1973, Tezuka et al. 1993) support the view that the solar UV-B produces flavonoid synthesis under the field conditions. Lignin biosynthesis, whose early steps (phenylpropanoid pathway) are shared with flavonoid synthesis, may be under the influence of UV-B, since UV-B makes plants tougher (Hashimoto and Tajima 1980).

http://ncr101.montana.edu/Light1994Conf/3_3_Hashimoto/Hashimoto text.htm

amoril · Oct 6, 2009

indifferent said:
Aye, that Joe Knuc article is a joke.

Sam did indeed say that he was unable to find any benefit to UV light, he used UV fluoro tubes in a greenhouse.

Two great points Sam made that folks need to bear in mind:

1. If UV was truly important in the production of resin and potency, then all indoor grown bud would lack resin and potency as fluoros and HIDs don't produce UV.

2. A high altitude cultivar such as a Highland Nepalese will have the same high if grown at sea-level with a lower UV level, the nature of the high and potency being genetically pre-determined.

Apart from the research done by Raphael Mechoulam in Israel where he exposed CBD acids in a petri dish to UV light at 285nm and got a small proportion to convert into THC acids, has anyone ever published any proper scientific work on this subject?

there is an obvious answer to both of Sam's claims. it lies with the genetic code. A plant is automatically coded to defend itself against the most common forms of harm, some basic virus protection, some defense from predation, etc.

sunlight has been a constant for the history of cannabis. its going to take more than a generation to breed out of the genetics.

that said, I never claim that UV light is essential for an indoor grower. I would advocate it for everyone, though, and would say that it should be a requirement in some form for any serious breeding project, be it included in the sun outdoors, or supplemented indoors.

lost in a sea · Oct 6, 2009

i personally agree with the theory, held by experts, that the cannabinoids in cannabis ,evolved through natural selection, as they block uv's from mutating cell dna.

but adding uv's now will not encourage the production, breeders decide how potent the progeny are by their selection.

all your potentially doing by adding uv's is mutating cells, but it would take very high levels.

in short this environmental factor affected this plants evolution, but there is no mechanism of the plant to respond by producing different compounds in response to uv's. uv's are one of the suns most destructive emitants, and for the first 2 billion years of this planets history u.v's scorched the surface and forced life to form at the bottom of the sea (if you believe modern consensus). i would maybe rethink the idea that just becuase its natural, your plants desire it in anyway.

on the other hand it is possible that the more complex molecules can be catalysed into more smaller, more desirable cannabinoids (i observed no difference). as a scientist that examins environmental factors, on a daily basis, all i can add is, i have compared the outcomes, and personally have ruled it out as being necessary for me.

amoril · Oct 7, 2009

here's another cog in the wheel.... and, also the study the MJ Man vid's pictures come from

there is one incredibly obvious implication to be had, on the last graphic on the page...

shows that the only compound permeable through the stalk of the capitate-stalked glandular trichome (CSGT) is a phenolic compound.

http://www.hempreport.com/issues/17/malbody17.html

GreenintheThumb · Oct 7, 2009

amoril said:
there is an obvious answer to both of Sam's claims. it lies with the genetic code. A plant is automatically coded to defend itself against the most common forms of harm, some basic virus protection, some defense from predation, etc.

sunlight has been a constant for the history of cannabis. its going to take more than a generation to breed out of the genetics.

But it's been waaaay more than a generation. We've been mostly breeding indoors with low UV light for decades. Has the potency or terpenoids changed? Certainly, but not because of a lack of UV but because of selection. And since our drugtypes are already programed for UV blocking terpenoid/flavinoid/cannabinoids evolutionarily what good comes from adding UV light now? We can already select the best and tastiest without the UV light and the side by side trials seem to show no effect.

amoril said:
that said, I never claim that UV light is essential for an indoor grower. I would advocate it for everyone, though, and would say that it should be a requirement in some form for any serious breeding project, be it included in the sun outdoors, or supplemented indoors.

But why? Your idea is that UV grown herb would show different phenos than nonUV grown herb which could effect a breeder's decision to cull/keep? But the side by side trials don't seem to support this.

Thanks for everyone's contributions. Looks like it certainly was a ripe topic for discussion.

Strainbrain · Oct 7, 2009

I've seen firsthand the results from UVB reptile bulbs in my own grow.

The changes it brings about in trichome coverage are visible to the naked eye. The changes that phenomenon brings to the potency are discernable with the head: I've blind-tested it with several friends who were unanimously correct in their assessments. I have not noticed a change in odor, flavor, or character of experience one bit between my three samples - 0%, 2% and 5% UVB lights respectively. Does it change what's in the trichomes? I dunno, seems like it doesn't... but there sure are more of them. (On longer stalks, too.)

To claim it is in any capacity essential, though, is also missing the point. The 0% sample still knocks my socks off, so clearly nobody needs UVB light to grow serious cannabis... but to then conclude that UVB has and furthermore cannot have an effect is simply flawed. You can build a delicious sundae without a cherry on top, but it'd still be better with the cherry. I'll never grow again without UVB.

I'd like to add here that I also see the likelihood that some strains are more- or less-sensitive to UVB. My 'tests' were done with my 'F' clone - of truly unknown genetic origin. It is absolutely sensitive to UVB. If you tested UVB with a strain which is all but insensitive to UVB, however, you'll probably be just as confused by my position as I am by yours... so let's not fling flames or start making wild accusations over this. We might well both be right.

-s

GreenintheThumb · Oct 7, 2009

Well thanks for sharing your experience. I think you're the first person I've spoken with who noticed a change. Do you have any pictures of the trials you conducted? I'd love to see them. And I agree there certainly could be line dependent UV effects.

elmanito · Oct 7, 2009

@Greeninthethumb
Check it for yourself with this small movie of a grow under a MH plasma light which contains UV a,b,c.This light has the spectra of the sun high in the mountains.The buds look much frostier than under HPS.
The light is 250 watt.No other light is used!!!!

http://www.youtube.com/watch?v=DE6yLuI1NPM

Namaste :smoweed:

DocLeaf · Oct 7, 2009

UV is highest in Spring!

Resin first occurs on underside of leaf blade.

UV has little impact on cannabinoid production.

Strainbrain · Oct 7, 2009

GreenintheThumb said:
Well thanks for sharing your experience. I think you're the first person I've spoken with who noticed a change. Do you have any pictures of the trials you conducted? I'd love to see them. And I agree there certainly could be line dependent UV effects.

Here's one with the 0% and 2% samples. (The CFL cabinet includes 2% UVB tubes in the T5 array.) The thicker coat and especially the longer trich stalks are pretty obvious.

And I don't have one of the 2 vs 5 side-by-side like that, but here are two pretty similar pics. The first one is from the same plant as above, grown for 8 weeks at 2%. The second from the plant I just cut which was grown with a 5% UVB bulb present for the final 4 weeks.

It's less clear and in reality less of a difference than in the examples above, but I think I see more green through the trich heads on the first photo than the second. In person, I assure you it's frostier this time than I've ever seen it. (This one was grown under the 250 hortilux + a 5% bulb, so unlike above the impact of mixed-spectrum light cannot account for the difference.)

I haven't smoke-tested the 5% bud, but everyone picks the 2% over the 0% - stating an obvious difference. IME it'll rip your face off if you're not ready for it. I expect the 5% to be more of the same, but it needs a couple weeks in the jar before it can get a fair shake.

Anecdotally, I have a grow-buddy who witnessed my results. His independent conclusion? He bought this 5% bulb, which he is now loaning me until I get my permanent solution for the tent in place. He keeps bugging me to bring it back... :smoke:

-s

Edit: This isn't useful for comparison, it's just pretty. 5% F, same crown as pictured above about a week before chop.

elmanito · Oct 7, 2009

DocLeaf said:
UV is highest in Spring!
Resin first occurs on underside of leaf blade.
UV has little impact on cannabinoid production.

I'm not sure if UV is higher in Spring.I would think more at the end of June , in July and begin of August.
The best varieties like Acapulco Gold, Highland Thai, Highland Nepalese were/are grown in the mountains.The high from these varieties are far more intense, psychedelic than most of the indoor varieties.

Namaste :smoweed:

VerdantGreen · Oct 7, 2009

interesting! - i have wondered about this.

would everyone agree that weed grown outside can be more potent and psychoactive than indoor weed?

if its not the spectrum that causes this then what is it? - perhaps longer veg = more mature plants = more potent??

V.

EvilTwin · Oct 7, 2009

Hi Guys,
Amoril, thanks for the Knoc reference. I'd never heard of Marijuana Optics and it may take me awhile to wend my way through the info.

Strainbrain, I like your idea of UV-B sensitivity being strain related. It certainly could be the case. Many other traits are. And nice shots. Clearly an improvement in trichome production and length.

DJ Short feels MH helps to bring out sativa characteristics...presumably from UV-B. It would be great to find a truly UV-B responive sativa that can give that old-time psychedelic high that I loved so much in the 60s.

As I was re-reading the thread, which is pretty active, it dawned on me that the primary conflict here is analogous to the "Nature vs Nurture" discussion in psychology. In our discussion, it's: what came along with the seed vs what we give to the plant to make it the best that it can be.

One issue that needs to be considered with UV-B supplementation is duration. How many hours? The full 12 hours of bloom?

And another question I've been pondering is: Would it be advantageous to run UV-B during the veg cycle as well? Start early on trichome production.
Peace,
ET

amoril · Oct 7, 2009

well, interesting you would make that last question EvilTwin, about UV in veg....

ive been thinking it may be more beneficial in veg than in flowering. to that effect, ive been using it to supplement veg lighting.

my reasoning is, if it does in fact effect the production of terpenes and flavanoids (either through diversification or quantity), then starting this process earlier would yield the most potential benefit.

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UV Light and Terpenoids

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