UV STOP good or bad?

[DonJones]

Amen to the smoking getting in the way!

Your comments about the purpose of the plant making resins and/or trichs is dead on -- Just because we are looking for resin and trichs and blasting the plant with UV, regardless of the spectrum, does NOT necessarily mean that UV is NOT harmful to the plant.

There are people who would make the same arguments about tapping rubber trees or maple trees but the fact remains that tapping both of those trees causes the tree to try and heal itself by secreting sap to heal the damage to the tree. There fore just because we are collecting the sap from the tree and getting what we want from the tree does NOT make tapping it good for the tree. It is widely known and universally accepted that over tapping a tree will eventually kill it, not just weaken it.

Great smoking man.

 

[Mutt]

I've read a theory that the crystals are to protect the plant. One grower said the desert grow of the same exact strain was frostier then in SoCal where it was a lil more humid. Which in a way would make sense as the resin would slow transpiration.

 

[BBFan]

I've done a lot of reading and researching on UVB an it's affects on our plants.

DonJones is correct in saying that UV hurts living organisms- just not all UV. Some UV light is actually within the action response spectrum for photosynthesis in plants. And, by the way, UVB is what causes our bodies to produce vitamin D.

But, while I'm hard pressed to find documented and scientifically verifiable results regarding UVB use (not UVA or UVC) and it's affects on trichomes and THC production (thank you DirtyOlSouth for pushing me in that direction!), there is still alot of info out there from respectable sources that make it worth a second look.

What I've read is that UVB causes a stress which causes our girls to produce trichomes as a defense mechanism.

I've also read that UVB helps turn certain cannibinols and acids in our trichs into THC.

I've only just completed my first grow with supplemented UVB lighting. I'm not at the point where I'm doing double blinds, but anecdotal responses and my personal observations have been very encouraging. My son says I could sell it for $50.00 a gram. All I know is one hit and I'm in lala land. Excellent for when I need to get some sleep.

(Note- I don't sell what I grow. Ever. I give most of my grows away as I don't need much. I seek my son's opinion as he has a lot of friends "in the business"- and he always takes the most anyway - though I've been cheap on giving him the plant that got the UVB light.)

I have saved much of the data I've found and would be more than happy to share with anyone interested!

 

[IRXMJ]

I've read a theory that the crystals are to protect the plant. One grower said the desert grow of the same exact strain was frostier then in SoCal where it was a lil more humid. Which in a way would make sense as the resin would slow transpiration.

I agree with this. When I grow outdoors in hot Israel Spring/Summer and/or my grow rooms are hotter in Autumn & Spring, the trich production is much more pronounced.

 

[IRXMJ]

I've done a lot of reading and researching on UVB an it's affects on our plants.

DonJones is correct in saying that UV hurts living organisms- just not all UV. Some UV light is actually within the action response spectrum for photosynthesis in plants. And, by the way, UVB is what causes our bodies to produce vitamin D.

But, while I'm hard pressed to find documented and scientifically verifiable results regarding UVB use (not UVA or UVC) and it's affects on trichomes and THC production (thank you DirtyOlSouth for pushing me in that direction!), there is still alot of info out there from respectable sources that make it worth a second look.

What I've read is that UVB causes a stress which causes our girls to produce trichomes as a defense mechanism.

I've also read that UVB helps turn certain cannibinols and acids in our trichs into THC.

I've only just completed my first grow with supplemented UVB lighting. I'm not at the point where I'm doing double blinds, but anecdotal responses and my personal observations have been very encouraging. My son says I could sell it for $50.00 a gram. All I know is one hit and I'm in lala land. Excellent for when I need to get some sleep.

(Note- I don't sell what I grow. Ever. I give most of my grows away as I don't need much. I seek my son's opinion as he has a lot of friends "in the business"- and he always takes the most anyway - though I've been cheap on giving him the plant that got the UVB light.)

I have saved much of the data I've found and would be more than happy to share with anyone interested!

I 'd be interested! Please share your info/experience with me!

 

[DonJones]

BBFan,

While I would like to review your information, especially in a separate thread where we wouldn't have to try to sift through the other issues here or a PM, I am even more interested at the moment in knowing how you supplement the UVB without increasing the UVA and UVC.

You said, I think, that UVB was what caused our bodies to produce vitamin D, which could very well be true since it has long been published that exposure to sunlight is what causes the production. What I don't understand is why sunblock lotions/creams list protection factors against both UVA and UVB. Also, I haven't noticed any ratings on UVC. Any explanations would be appreciated.

Incidentally, most medical treatments involve using something that is basically harmful in uncontrolled circumstances to harm an unhealthy condition more than what it does the healthy condition to achieve an overall improvement in health. Does that sound as confusing to you guys and gals as it does to me? I sure hope not. Hopefully you will understand what I meant because I sure didn't make it sound like I wanted it but I can't think of a better way to say it right now.

Great smoking and happy 2010.

 

[BBFan]

I 'd be interested! Please share your info/experience with me!

Hi IRXMJ!

Hope all is well with and for you. I will post some info at the end of this post. There's plenty more where that came from, and some of it can be quite tedious. I'll be happy to share as much as you want. Let me know.

But first I would like to respond to DonJones' post.

I am even more interested at the moment in knowing how you supplement the UVB without increasing the UVA and UVC.

Hello Don!

I am introducing UVB to my plants via a self ballasted mercury vapor lamp. These lamps are readily available from pet supply companies. Before I settled on the Zoo Med lamp, I looked at the output and efficacy of the different lamps that are readily available to the general public, specifically for reptile health and breeding.

I don't think any of them produced UVC wavelengths, but did produce both UVA and UVB. UVC from the sun never reaches the earth as it is absorbed in the earth's atmosphere, that's why you don't need sunblock for it.

I'd like to clarify an earlier statement I made regarding UVB wavelengths and whether they are harmful. I was referring to a small portion of the UVB spectrum in that statement. In large doses, I think most UVB is harmful.

Incidentally, most medical treatments involve using something that is basically harmful in uncontrolled circumstances to harm an unhealthy condition more than what it does the healthy condition to achieve an overall improvement in health. Does that sound as confusing to you guys and gals as it does to me? I sure hope not. Hopefully you will understand what I meant because I sure didn't make it sound like I wanted it but I can't think of a better way to say it right now.

I think I get what you're saying. Kind of like chemotherapy and radiation therapy used in the treatment of certain cancers. Both of these treatments kill good cells, but the benefits of destroying the bad cells outweighs the destruction of the good cells.

Same thing, based on what I've read, regarding UVB and it's effects on our plants. MJ (and other plants) produce trichomes to protect against cellular damage from UVB. It is a defense mechanism. But the end result is better for us (maybe not so the plant ).

Also, if you read and believe the following article but Joe Knuc, the result is also more potent THC.

Happy smoking to you too.

 

[BBFan]

Here is a short article I found regarding UVB and it's effects on MJ plants. The source I found credited Joe Knuc as the author.

An elaboration on the phytochemical process that makes THC
By Joe Knuc

"Pate (1983) indicated that in areas of high ultraviolet radiation exposure, the UVB (280-320 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 UVB has also been experimentally determined by Lydon et al. (1987)."

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.

(b)"The maximum UVB irradiance near the equator (solar elevation angle less than 25 deg.) under clear, sunny skies is about 250 µW/cm2. It was observed that the daily solar UVB in Riyadh, Saudi Arabia (N24.4Lat.) decreased from September to December by about 40% (Hannan et al. 1984). The further a person is from the tropics, the less UVB radiation there is: the average annual exposure of a person living in Hawaii is approximately four times that of someone living in northern Europe." Below are some UVB readings taken in Hoyleton, Illinois, on a clear sunny day in June by David Krughoff as reported in Reptile Lighting 2000.

7am: 12 microwatts/cm2
8am: 74 microwatts/cm2
9am: 142 microwatts/cm2
10am: 192 microwatts/cm2
11am: 233 microwatts/cm2
12pm: 256 microwatts/cm2
1pm: 269 microwatts/cm2
2pm: 262 microwatts/cm2
3pm: 239 microwatts/cm2
4pm: 187 microwatts/cm2
5pm: 131 microwatts/cm2
6pm: 61 microwatts/cm2

 

[BBFan]

Here is an excerpt from R.C. Clarke in his book "Marijuana Botany".

Conversion of CBD acid to THC acid is the single most important reaction with respect to psychoactivity in the entire pathway and the one about which we know the most. Personal communication with Raphael Mechoulam has centered around the role of ultraviolet light in the bio-synthesis of THC acids and minor cannabinoids. In the laboratory, Mechoulam has converted CBD acid to THC acids by exposing a solution of CBD acid in n-hexane to ultraviolet light of 235-285 nm. for up to 48 hours. This reaction uses atmospheric oxygen molecules (02) and is irreversible; however, the yield of the conversion is only about 15% THC acid, and some of the products formed in the laboratory experiment do not occur in living specimens. Four types of isomers or slight variations of THC acids (THCA) exist. Both Delta1-THCA and Delta6-THCA are naturally occurring isomers of THCA resulting from the positions of the double bond on carbon 1 or carbon 6 of the geraniol portion of the molecule They have approximately the same psychoactive effect; however, Delta1-THC acid is about four times more prevalent than Delta6-THC acid in most strains. Also Alpha and Beta forms of Delta1-THC acid and Delta6-THC acid exist as a result of the juxtaposition of the hydrogen (H) and the carboxyl (COOH) groups on the olivetolic acid portion of the molecule It is suspected that the psychoactivity of the a and ~ forms of the THC acid molecules probably does not vary, but this has not been proven. Subtle differences in psychoactivity not detected in animals by laboratory instruments, but often discussed by marijuana aficionados, could be attributed to additional synergistic effects of the four isomers of THC acid. Total psycho-activity is attributed to the ratios of the primary cannabinoids of CBC, CBD, THC and CBN; the ratios of methyl, propyl, and pentyl homologs of these cannabinoids; and the isomeric variations of each of these cannabinoids. Myriad subtle combinations are sure to exist. Also, terpenoid and other aromatic compounds might suppress or potentiate the effects of THCs.

Environmental conditions influence cannabinoid biosynthesis by modifying enzymatic systems and the resultant potency of Cannabis. High altitude environments are often more arid and exposed to more intense sunlight than lower environments. Recent studies by Mobarak et al. (1978) of Cannabis grown in Afghanistan at 1,300 meters (4,350 feet) elevation show that significantly more propyl cannabinoids are formed than the respective pentyl ****-logs. Other strains from this area of Asia have also exhibited the presence of propyl cannabinoids, but it cannot be discounted that altitude might influence which path of cannabinoid biosynthesis is favored. Aridity favors resin production and total cannabinoid production; however, it is unknown whether arid conditions promote THC production specifically. It is suspected that increased ultraviolet radiation might affect cannabinoid production directly. Ultra-violet light participates in the biosynthesis of THC acids from CBD acids, the conversion of CBC acids to CCY acids, and the conversion of CBD acids to CBS acids. However, it is unknown whether increased ultraviolet light might shift cannabinoid synthesis from pentyl to propyl pathways or influence the production of THC acid or CBC acid instead of CBD acid.

 

[DonJones]

BBFan,

Your example of chemotherapy and/or radiation is exactly what I was thinking of only I was thinking more along the idea of antibiotics, which isn't quite as clear as your example.

You finally showed me a use for MV lights in growing! I had never heard of them being good for anything in growing before, but I thought there must one somewhere.


Okay, now for the nitty gritty -- How much do you use and in what combination with HPS?

Do I need to have a light for each large plant like I use my HPS 400s or does it diffuse enough to just hang one high in the general center of the area?

My active flowering area in the room is approximately 6' x6' with an occasional enlargement up to 6' x8'. I currently run 3 HPS 400s and have an additional 4 MH 400s that I can use if needed. I'm in the process of acquiring more HPS with a goal of 6 HPS 400s for use and an additional one for reserve in case of a failure of one of the primary ones.

Do you have any quantitative information on the difference it makes or mostly just subjective impressions? I'm very aware that the "objective hard data" is not too likely to be within the means of most growers, but I've been surprised before at what some growers have access to.

Getting back to the original question on the post, (a) of the first quote "(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" seems to imply that the UV spectrum of MH & HPS lights is so slight that it isn't going to make any difference to a grow operation whether it is filtered out or not.

The second quote from Clarke doesn't seem to help much from a practical standpoint, but IO guess maybe understanding it might help to understand something more practical later.

Thanks for the information. I'm always grateful for any way to improve my yield, which to me means the active ingredients not just the volume/weight of the bud I get.

Great smoking.

 

[BBFan]

You finally showed me a use for MV lights in growing! I had never heard of them being good for anything in growing before, but I thought there must one somewhere.


Okay, now for the nitty gritty -- How much do you use and in what combination with HPS?

Do I need to have a light for each large plant like I use my HPS 400s or does it diffuse enough to just hang one high in the general center of the area?

Do you have any quantitative information on the difference it makes or mostly just subjective impressions? I'm very aware that the "objective hard data" is not too likely to be within the means of most growers, but I've been surprised before at what some growers have access to.

seems to imply that the UV spectrum of MH & HPS lights is so slight that it isn't going to make any difference to a grow operation whether it is filtered out or not.

DonJones-

Please understand, I am not advocating the use of mercury vapor lights for your space. IMO, about the only thing they're good for is producing heat. However, the light I use is an enhanced mercury vapor bulb that provides some light in the UVB spectrum. It is specifically labeled and sold as such. Even the bulb I used generated heat which was a constant battle. UVB lights are also available in flouros, perhaps that would better suit your needs.

As far as quantitative data, I cannot provide any. I have more research if you're interested in further reading- but nowhere is there any definitive or quantifiable information regarding results. I can only offer what I have read and my own observations, which I stated were inconclusive. My own experience in using the uvb was aimed at one plant to compare to the others grown under otherwise same conditions. I introduced the uvb while the plants were in veg at about 1 hour a day and continued exposure up through flowering to a maximum of about 6 hours a day.

DirtyOlSouth is someone who really pushed me to experiment with UVB lighting. I don't believe he has any specific data either, but he does offer personal anecdotal information which may be of some value to you in your research. Without gas chromatography or some other method to measure THC content, I don't know that I could ever provide more than an opinion. I am not a scientist, I only play one on TV and here at MP .

My research has shown that MH produces more wavelengths in the UV spectrum. But this is again something that is not commonly or readily available beyond the occassional warning labels that come with the bulb.

All of this, from my understanding, points to improved thc content and potentiation; nothing about improved yield.

Probably the best anecdotal evidence would come from someone who grows the same cuts both indoor and outdoors- though I beleieve I am dosing my plants more than an outdoor grower in northern latitudes would receive. I no longer grow outdoors and have nothing to use for comparison.

Happy Smoking to you too!

 

[DonJones]

BBFan,

Damn, here you go and get me all excited and then tell me you don't have any idea how much to use or how much good it does.

In YOUR opinion, does it seem to help if the plants are vegged under MH or do they seem to have enough UV without it?

What does anyone know about supplementing the HPS with MH, like how much and does it need o9t be the same ration for each plant or can I just hang a couple of MHs near the center area of the room and let it spread out?

Sorry to get off track.

BBFan, I'm just dissapointed, and not with you.

Great smoking.