[Tonygreen]

Check this out guys...

https://books.google.com/books?hl=en&...20uv-b&f=false

On page 31 if you scroll down you get into some good stuff and an interesting hypothesis about thc.

[Green_science]

Hey everyone,thread updated and welcome, I think all of you're Q.'s have been answered in my updated post, let me know if there's anything else

GS

[Sam_Skunkman]

What happened to Green science? Please run the test and analyze the results and post them!!
I ran a test a bit like this 20 years ago.
I had several different clones of high THC varieties, and industrial hemp, and a wild cannabis variety from the mountains.
I placed each clone in rows of five so they had a chance to be exposed to too high of levels, medium, and low levels, depending on the distance from the light sources.
To cut to the chase, no increase compared to controls without UV-B.
In fact the plants closest to the lights were a bit zapped and had lower plant weights and lower Cannabinoid levels.
(In my own opinion using organic soils to increase root mass, which gives Cannabis with improved terpene yield and better Cannabis yield is much better then UV-B supplement.)

Tonygreen,
As for On page 31 if you scroll down you get into some good stuff and an interesting hypothesis about thc. They quote Lydon and Pate, but Pate did my experiments with me
setting them up and measuring the UV-B levels, as well as testing the results on our GC.
He was unable to increase the THC levels. Lydon thinks CBD can be converted to THC, but most Cannabis grown in the west has no CBD to start with. Lydon also only dosed the plants with UV-B for only 40 days, part of those when the plant was still in veg. He also said no increase in THC in hemp plants so I guess CBD does not get converted to THC by UVB?
We tried several times, zero THC increase. I have never seen any lab results that showed an increase in THC from UVB exposure, I have never seen Lydon's work replicated, except when I tried but got no increase in THC.
As for "Marijuana Optics" anyone that reads it and thinks it is science needs to stop smoking so much.
Get all three of Lydon's papers and try to repeat the work, if I remember correctly he did not even use clones for the work, for sure in the case of Lydon's 1985 Thesis, I think the 1987 paper also. I will go find the papers and re-read them....

-SamS

[k-grower]

Originally Posted by Sam_Skunkman

What happened to Green science? Please run the test and analyze the results and post them!!
I ran a test a bit like this 20 years ago.
I had several different clones of high THC varieties, and industrial hemp, and a wild cannabis variety from the mountains.
I placed each clone in rows of five so they had a chance to be exposed to too high of levels, medium, and low levels, depending on the distance from the light sources.
To cut to the chase, no increase compared to controls without UV-B.
In fact the plants closest to the lights were a bit zapped and had lower plant weights and lower Cannabinoid levels.
(In my own opinion using organic soils to increase root mass, which gives Cannabis with improved terpene yield and better Cannabis yield is much better then UV-B supplement.)

Tonygreen,
As for On page 31 if you scroll down you get into some good stuff and an interesting hypothesis about thc. They quote Lydon and Pate, but Pate did my experiments with me
setting them up and measuring the UV-B levels, as well as testing the results on our GC.
He was unable to increase the THC levels. Lydon thinks CBD can be converted to THC, but most Cannabis grown in the west has no CBD to start with. Lydon also only dosed the plants with UV-B for only 40 days, part of those when the plant was still in veg. He also said no increase in THC in hemp plants so I guess CBD does not get converted to THC by UVB?
We tried several times, zero THC increase. I have never seen any lab results that showed an increase in THC from UVB exposure, I have never seen Lydon's work replicated, except when I tried but got no increase in THC.
As for "Marijuana Optics" anyone that reads it and thinks it is science needs to stop smoking so much.
Get all three of Lydon's papers and try to repeat the work, if I remember correctly he did not even use clones for the work. Maybe I am mixed up? I will go find the papers and re-read them....

-SamS

it is all depended on genetics of the plant, just make account here and read the science study of uv-b
https://onlinelibrary.wiley.com/doi/1...757.x/abstract

from the study -

"The effects of UV-B radiation on photosynthesis, growth and cannabinoid production of two greenhouse-grown C. sativa chemotypes (drug and fiber) were assessed. Terminal meristems of vegetative and reproductive tissues were irradiated for 40 days at a daily dose of 0, 6.7 or 13.4 kJ m-2 biologically effective UV-B radiation. Infrared gas analysis was used to measure the physiological response of mature leaves, whereas gas-liquid chromatography was used to determine the concentration of cannabinoids in leaf and floral tissue.

There were no significant physiological or morphological differences among UV-B treatments in either drug- or fiber-type plants. The concentration of Δ9-tetrahydrocannabinol (Δ9-THC), but not of other cannabinoids, in both leaf and floral tissues increased with UV-B dose in drug-type plants. None of the cannabinoids in fiber-type plants were affected by UV-B radiation.

The increased levels of Δ9-THC in leaves after irradiation may account for the physiological and morphological tolerance to UV-B radiation in the drug-type plants. However, fiber plants showed no comparable change in the level of cannabidiol (a cannabinoid with UV-B absorptive characteristics similar to Δ9 THC). Thus the contribution of cannabinoids as selective UV-B filters in C. sativa is equivocal."

[Tonygreen]

Thanks for posting Sam!

[Green_science]

@Sam_Skunkman, Sorry my friend there was some confusion on my part with this thread, I do not know when or how post#2 appeared and can be deleted, I did not think this thread was going to make it, until I just see it was eventually permitted and made active by you guys.

I have ordered the parts and they should be here and setup for Friday, I purposefully ordered a ballast that has a dimmer feature that gently powers the bulbs on and off, to replicate Dusk/Dawn, this feature takes 30 minutes each side,
The ballast which has a built in timer has a minimum day length of 10 hours which is okay, once we minus the hour for soft start/stop feature it equates to 9 hours of full power UVB supplementation per day, PERHAPS a little much, but I really cannot see it hindering this test.

I will report back when things are setup and running, this will be at latest Monday, in the meanwhile if anyone has any request let me know?

[Sam_Skunkman]

Great! Be sure you have control plants grown exactly the same with no UV-B, as well as a lab that will test for the Cannabinoids as well as the terpenes. Good luck, I really would like to see the results analyzed for yield, Cannabinoids as well as preference by smokers. The reason I did the work was because I wanted to see if UV-B could help, I just could not prove it did.
-SamS

Originally Posted by Green_science

@Sam_Skunkman, Sorry my friend there was some confusion on my part with this thread, I do not know when or how post#2 appeared and can be deleted, I did not think this thread was going to make it, until I just see it was eventually permitted and made active by you guys.

I have ordered the parts and they should be here and setup for Friday, I purposefully ordered a ballast that has a dimmer feature that gently powers the bulbs on and off, to replicate Dusk/Dawn, this feature takes 30 minutes each side,
The ballast which has a built in timer has a minimum day length of 10 hours which is okay, once we minus the hour for soft start/stop feature it equates to 9 hours of full power UVB supplementation per day, PERHAPS a little much, but I really cannot see it hindering this test.

I will report back when things are setup and running, this will be at latest Monday, in the meanwhile if anyone has any request let me know?

[Green_science]

Originally Posted by Sam_Skunkman

Great! Be sure you have control plants grown exactly the same with no UV-B, as well as a lab that will test for the Cannabinoids as well as the terpenes. Good luck, I really would like to see the results analyzed for yield, Cannabinoids as well as preference by smokers. The reason I did the work was because I wanted to see if UV-B could help, I just could not prove it did.
-SamS

Sure thing, the control sets are in the same NFT tray drinking the same feed in the same environment, also they are genetic clones. For testing purposes produce used will come from opposite sides, one side will be receiving near NILL UVB whilst the other will be supplemented with levels (at least similar) to that in the Hindu Kush valleys, of coarse we aren't in lab conditions but the differentials other than the one we are testing are MINIMAL I assure you, so it is safe to say this test is pretty darn accurate.

I have run a few ops supplemented with UVB. VVVVVVVVV



In the above instance something that I would consider unusual happened, it seemed that leaves around the UVB bulbs yellowed early, and, much more than usual, and whilst using my usual methods.

The strain in question was one I am not familiar with however, so perhaps I just couldn't dial it in, pretty unlikely tbh.

I am uncertain of the results, but it seemed, and I say it cautiously, that the uvb supplementation was possibly responsible for accelerated maturation without compromising yield, sure I was unfamiliar with the strain, but you can almost see it in the pic, the plants that had an abundunce of UVB, seemed more ripe and larger, before others with less access to UVB, this definitely wouldn't be the case if the fact were simply light bleaching, heat burn or a deficiency. None of this is concrete and I am not even sure if I believe it myself, however the test in this thread is going to be quiet accurate, so, the million doller question will be answered within the next 2 months. I do not sell UVB lights, I do not own any shares in any party's that sell UVB lights, I have nothing to gain from promoting the use of UVB lights etc etc, so you can all have plenty of faith in this being a honest, fair and unbiased test that I will perform as accurately as possible with no ulterior motives involved, it's simply to further extend our knowledge

[Pepe le skunk]

Just wanted to chim in real quickly that if you are using repti-glo uvb lights they suck compared to the better UVB bulbs on the market. All tests on those bulbs have shown without the correct glass(Quartz glass) to transmit UVB, very little result will come from these junk bulbs. Want proof? Here you go measuring light output with a meter.

See what Dr Baines has to say.

https://www.youtube.com/watch?v=AUu24MNO2Ho


....and if you are not familiar with her, please google her and please visit her web-site.

She is the top expert on UV and advises Zoos all over the world.

And she does independent testing for Arcadia, Zoo med and Lucky Reptile (german) among many others...

She does NOT endorse any products...

but you can see what ones she presents in her demonstrations.

They only ones worth purchasing are the Zoo med Reptisun UVB 10 and the Best 12% HO UVB bulbs from Arcadia. Arcadia D3+ T-5 46 Inch 54 Watt *12% Desert UVB is right now the best ones to use. They also have Mercury Vapor lamps in 160 watt spot bulbs HO UVB lights.
Any tests done using any other bulbs will show little difference because, "You are not doing it right."

Last here is a picture of UVB lights over a nice little crop. Only thing I will change is the distance between the lights and the plants. Will try and get it as close as possible to the plants.
Pictured is 4 36 watt Reptisun UVB 10 bulbs and 2 96 watt HO 7% UVB bulbs. Not available anymore. At least they are HO Bulbs.

[Pepe le skunk]

One last thing, You will need to move(rotate) the plants around to get the best exposure to the UVB light. I turn the plants every 3 days when watering so a different side gets exposed to that light source.

I used to work with Zoo Med years ago and is how I learned about UVB lights and what makes one better than the others.
Hope that helps.