[mpd]

This is going to be a really great thread for ICG members to contribute to and learn from as we move forward with creating the testing conditions to provide more potent pot by making sure our indoor grows get the UV-B ultraviolet light they need to convert all of the plant's production of cannabidiol into that chemical we love so much to take for a swim...

I read one guy's post who said that indoor marijuana had almost no THC in it because the plants only got UV-A and/or UV-C light exposure, so full transformance from the cannabinoids that are useless (principally CBG and cannabidiol), to THC couldn't really take place. He said that indoor pot was a big scam and that people were being stupid, etc., etc.

He did have a nugget in all the extraneous information floating around in the thread. The fact that photons in UV-B bandwidth (285 nm. to 325 nm. - roughly) were particularly energetic and were a requirement for these cannabinoids to morph into extra potent THC.

I found other references to this item and I think it is time we put the myths to rest - don't you?

We have more issues than just shining a sunlamp in the grow room to see what happens. The issues we have to deal with are, in my opinion, the following general assumptive tests:

1. Does the use of a UV-B light have an affect on freshly cut marijuana in terms of boosting the final production of THC?

2. What is the dosage of UV-B light required to provide the highest boosting of the final production of THC in freshly cut marijuana?

3. Does the use of a UV-B light dosage on marijuana plants at the beginning, middle, or end of the plant's life increase the final production of THC?

4. If so, what stage is best to use? How long to use (dose question again)?

These innocent sounding questions are masking a testing program of major proportions in order to find the answers. I would like some help on this. Please post your thoughts if you are interested in this caper, and then I'll share some of my findings in my research so far on this point, and perhaps we can then configure a testing program to find the answers.

[Big Eggy]

Uv-b Light makes it produce more trichomes to protect itself from the suns rays... that what im lead to belive anyway. outdoor weed is ment to taste better but i'v never brought that has been for sure and i'v never grown outside. Using a hps and MH together is ment to be the best as the mh has more of the blue end of the scale, i heard of a guy who used aquaium uvb tubes with a hps and noticed a difference but they were fairy costly.

[Big Eggy]

just thought.. where you say freshly cut mj... your not ment to cure it in the light... i dont know if that goes for black lights though

[mpd]

UV-B is not in the visible spectrum. A sunlamp costs $45 on good old E-Bay, so I don't think we are talking about a major retrofit cost at this point in time.

The HID bulbs on the market won't get us there because they are all UV shielded by law, so there are no UV-B emissions unless you buy an ultraviolet light that produces a fair amount of UV-B.

But how much is needed? How often?

I like the quick responses and engagement so far. Let's hope it keeps up.

[Big Eggy]

Effects on plants in the sea, in freshwater and on land are of fundamental importance because of their position at the base of all other food chains. By nature, plants have evolved to maximize the surface area they expose to sunlight, but consequently their exposure to damaging UV-radiation is also increased. Elevated UV exposure can cause temporary or irreversible damage to photosynthetic apparatus (including the bleaching of the pigments which trap the sun's energy), to processes of cell division and growth regulation, and to the composition and replication of genetic material. Consequences include a reduction in growth yield, changes in levels and effects of plant hormones and alteration of periods of dormancy, flowering, etc.

Now i still belive that Uv-b Produces more trichomes as a defence but the above would suggest that too much can be damaging.. how much i dont know..... i'll keep looking though.

Eggy

[Big Eggy]

Ultraviolet radiation
Another stress to which plants are subject results from their daily exposure to sunlight. While necessary to sustain photosynthesis, natural light contains biologically destructive ultraviolet radiation. This selective pressure has apparently affected the evolution of certain defenses, among them, a chemical screening functionally analogous to the pigmentation of human skin. A preliminary investigation (Pate 1983) indicated that, in areas of high ultraviolet radiation exposure, the UV-B (280-315 nm) absorption properties of THC may have conferred an evolutionary advantage to Cannabis capable of greater production of this compound from biogenetic precursor CBD. The extent to which this production is also influenced by environmental UV-B induced stress has been experimentally determined by Lydon et al. (1987). Their experiments demonstrate that under conditions of high UV-B exposure, drug-type Cannabis produces significantly greater quantities of THC. They have also demonstrated the chemical lability of CBD upon exposure to UV-B (Lydon and Teramura 1987), in contrast to the stability of THC and CBC. However, studies by Brenneisen (1984) have shown only a minor difference in UV-B absorption between THC and CBD, and the absorptive properties of CBC proved considerably greater than either. Perhaps the relationship between the cannabinoids and UV-B is not so direct as first supposed. Two other explanations must now be considered. Even if CBD absorbs on par with THC, in areas of high ambient UV-B, the former compound may be more rapidly degraded. This could lower the availability of CBD present or render it the less energetically efficient compound to produce by the plant. Alternatively, the greater UV-B absorbency of CBC compared to THC and the relative stability of CBC compared to CBD might nominate this compound as the protective screening substance. The presence of large amounts of THC would then have to be explained as merely an accumulated storage compound at the end of the enzyme-mediated cannabinoid pathway. However, further work is required to resolve the fact that Lydon's (1985) experiments did not show a commensurate increase in CBC production with increased UV-B exposure.

This CBC pigmentation hypothesis would imply the development of an alternative to the accepted biochemical pathway from CBG to THC via CBD. Until 1973 (Turner and Hadley 1973), separation of CBD and CBC by gas chromatography was difficult to accomplish, so that many peaks identified as CBD in the preceding literature may in fact have been CBC. Indeed, it has been noted (De Faubert Maunder 1970) and corroborated by GC/MS (Turner and Hadley 1973) that some tropical drug strains of Cannabis do not contain any CBD at all, yet have an abundance of THC. This phenomenon has not been observed for northern temperate varieties of Cannabis. Absence of CBD has led some authors (De Faubert Maunder 1970, Turner and Hadley 1973) to speculate that another biogenetic route to THC is involved. Facts scattered through the literature do indeed indicate a possible alternative. Holley et al. (1975) have shown that Mississippi-grown plants contain a considerable content of CBC, often in excess of the CBD present. In some examples, either CBD or CBC was absent, but in no case were plants devoid of both. Their analysis of material grown in Mexico and Costa Rica served to accentuate this trend. Only one example actually grown in their respective countries revealed the presence of any CBD, although appreciable quantities of CBC were found. The reverse seemed true as well. Seed from Mexican material devoid of CBD was planted in Mississippi and produced plants containing CBD.

Could CBC be involved in an alternate biogenetic route to THC? Yagen and Mechoulam (1969) have synthesized THC (albeit in low yield) directly from CBC. The method used was similar to the acid catalyzed cyclization of CBD to THC (Gaoni and Mechoulam 1966). Reaction by-products included cannabicyclol, delta-8-THC and delta-4,8-iso-THC, all products which have been found in analyses of Cannabis (e.g., Novotny et al. 1976). Finally, radioisotope tracer studies (Shoyama et al. 1975) have uncovered the intriguing fact that radiolabeled CBG fed to a very low THC-producing strain of Cannabis is found as CBD, but when fed to high THC-producing plants, appeared only as CBC and THC. Labeled CBD fed to a Mexican example of these latter plants likewise appeared as THC. Unfortunately, radiolabeled CBC was not fed to their plants, apparently in the belief that CBC branched off the biogenetic pathway at CBD and dead ended. Their research indicated that incorporation of labeled CBG into CBD or CBC was age dependent. Vogelman et al. (1988) likewise report that the developmental stage of seedlings, as well as their exposure to light, affects the occurrence of CBG, CBC or THC in Mexican Cannabis. No CBD was reported.

It a bit much for me to understand but from what i can make out higher levels of uv-b light decrese the pressance of CBD... does it convert and store it as THC???

[Big Eggy]

Just a quote i picked out of an old discution.

"The Earth's atmosphere filters UVB light. There is more UVB light at high altitudes than at sea level. Also, sunlight at the equator takes the shortest route through the atmosphere"

This might be why Natral Stains that originated from the mountains in Afganistan and other tropical stains are higher in potency?

here's the link if you fancy reading it all: https://www.ghostsearchers.com:8080/c...agreement.html

Eggy

just thought i should add this:
"The UVB light the plant receives from an MH lamp does increase the plant's potency slightly at the cost of yield, but there are better ways to introduce UVB light into the grow room. They include reptile lights, which emit about 10% UVB, and tanning lamps"

plenty to think about!
it seems to me (and who am i? )
that it make the plant stress and protect it self which is not going to improve potency just the trichome count?
i prefer to try to keep my babies stress free and they repay me with strong crystaly bud so if it aint broke i dont fix.
just my opinion.
but time will tell no doubt-we all here to learn

[Big Eggy]

the problem is that a good uvb lamp (medical ones) cost £££'s and it can be harmful to us causing Cancers and other nastys that we don't want..

yeh thats a point worth concidering eggy! the uvb must be shielded in hid lights for good reason so if we did all start adding it, it would have to be on a different switch to the hid's so as to be able to turn it off when tending the plants with the lights on??