UVb an experiment

[Weezard]

"You just raised an interesting point without knowing. What the high mountain areas and equatorial regions share in common......is high levels of (drum roll please) UV radiation."

If your serious about UV, jus go to the equator an turn left until you spot a mountain.
Climb said mountain and build a heated, quartz roofed, greenhouse at about 13,000', yah
Now yer cookin'.

Aloha,
Weeze

[headshake]

OM, you are correct, the Hindu Kush mountain range is in south-central Asia. i guess i made a lazy statement and just lumped it in with the mid-east due to the seemingly endless war still happening in those two regions.

there is a lot of hash made in that region!


-shake

[khyberkitsune]

I would be down to put some of my older blue-dominant LED equipment on at-cost sale to help with the experiment.

Actually, depending on what happens in the next couple of weeks, I might be able to flat-out donate it. Dichroic, 2:1 blue:deep red.

I also have pure landraces, let me know what you'd prefer - Mexico, China, Russia, Turkey, Hungary. I'll get to work on making more seed stock to donate to the experiment.

[MimbresValley]

This was a good read, good post!:thumbsup:
I enjoyed very much

[oldmac]

HEALTH WARNING

Looking into UVc, I found that it is just as bad health wise as UVb!!!

Not good for skin or eyes. Use care if working with any UV source.

OM

[oldmac]

I would be down to put some of my older blue-dominant LED equipment on at-cost sale to help with the experiment.

Actually, depending on what happens in the next couple of weeks, I might be able to flat-out donate it. Dichroic, 2:1 blue:deep red.

I also have pure landraces, let me know what you'd prefer - Mexico, China, Russia, Turkey, Hungary. I'll get to work on making more seed stock to donate to the experiment.

khyber,

I have some landrace strains, mostly sativas, but they are not suitable for indoor growing. They just grow sooo big. In fact, to do the Thai sativa in my greenhouse that only has 8' headroom, I need to use vertical growth inhibitor. This stuff grows to 14-16' outdoors, but where I am in the NE US, it needs to start indoors, then greenhouse then outside to get full size.

Besides, allmost everything grown today is a hybred, which is what I'm concerning myself with here.

Nice offer for your used panels, but.... I suffer from a rare but serious side effect when exposed to LED grow lights that are mfg. offshore. It is an allergic reaction that has Turret's like symptoms and starts out with my cursing the mfg and marketeers of such products and then winds up with my slandering 2 billion people, most of whom I've never met.

OM

[clongo]

[quote=oldmac]I tend to grow small plants, SOG size, so I usually don't veg very long. For this experiment I tried to veg as long as possible to maximize any effect that might happen during veg growth. The lighting seemed to work out well for all chambers and got to veg for 6 weeks while maintaining plants of just 10-12".

First general obsevation at the end of vegative stage;
All plants stayed short, compact, node spacing was tight and looked good. But the chamber with UVb looked healthier, the leaves where fatter (we've seen this before) and the amount of leaf growth was a tad more then the other 2 chambers.

At the end of flowering; the chamber that saw UVb from the beginning had the heaviest green wieght, followed by the chamber that had UVb for flowering. The leaves of the UVb/flowering chamber got thicker (like the first experiment I ran) as they progressed. The 2 chambers that used UVb, again just plain "looked" healthier then the no UVb control chamber.

Now the most interesting part, did it (UVb) put more trichomes on the plant? Well yes and no; for the chamber using UVb from the beginning, 3 of the 5 strains showed a remarkable difference in trichome production.
The biggest difference was in the Pure Power Plant, everyone (myself, the fellow doing the work, and my partner from another grow) agreed there was a big difference in the amount of trichomes on these plants. The Shiva Skunk and the Cheese also showed more trics, not as dramatic as PPP but we were all in agreement there was a significant difference from this chamber compared to the other 2 chambers. The White Rhino was more diffucult to call. Since it was sooo frosty even in the controlled chamber, we came up with a split decsion. I felt there was really no improvement, my partner thought there was a slight improvement and the grunt said "I can't tell". We all agreed abt the "apricot", there was no improvement in trichome production.

Chamber #1; UVb for veg/flower: more trichomes on 3 of 5 strains run This is because some strains will do better outdoors with higher irradiance values in the short blue spectrums that affect maturity of the plant w/ time factor. The heavyest finished weight because of blue light contamination. Trichomes went cloudy then amber at finish Thc is degraded by light and more so by more energetic particles of UV, peak thc by percent in resin is when there is best balance between number and size of capitate trichromes and the number that are turning cloudy, which represents the beginning of byproduct buildup in the already matured calyx. imho people do not like the heady buzz of too much thc and prefer the marginal benefit tradeoff of less thc for more modulation by cannabinoid byproducts and more mature terpenes present in more "overripe" buds.

Chamber #2; UVb for flower only: no significant trichome production improvement. Less finished weight then chamber #1, but more then chamber #3. Trichomes went cloudy then amber at finish.

Chamber #3; No UVb: trichomes, well we got what we got. The finished weight was the least of the 3 chambers. Trichomes slowly got cloudy and never went amber. (well I did find 2 ambers on the WR using the "eyeclops")


Well there you have it. The question that I have for myself is, can UVb from the begining, make the same difference in my own grows where I usually just veg for 7-10 days or in aero/fog trays where I go from the clonner to flower tray directly? Guess I just gotta try it and see.

Hope this all makes sense (cents) to everybody. Any questions, please feel free to ask. :thumbsup:[/QUOT

jah bless

longo :rasta:

[knna]

The heavyest finished weight because of blue light contamination

I wouldnt jump to that conclusion so fast. As oldmac designed the experiment, with supplement floro light to compensate the lights used to give UVB, there is no a large difference in blue content of both spectrums used.

Botanist experiments showed that many plants reduce weight when exposed to UVb light, but it cant be generalized. Not all species react that way, some has proven to increase weight under moderate UVB lighting. And it seems cannabis is one of them. And anyway, weight reaction to UVB is strongly dosage dependent.

Many plant species dont show increased or decreased weight under UVB. Cannabis, at worst, seems to be one of them. This referred to total plant matter accumulation. But if we take bud weight alone, in which resin account for a noticeable part of total weight, enhanced resin production may account for a significant weight increase. Still if bud weight without resin weight less, it well may be that overall weight is larger. And at the end, we are after the resin.

Ideally, we should be able to weight resin alone in order to compare results accurately. But extracting resin alone and weighting it is not easy to do accurately, so usually we have to make some guesses and assumptions when analyzing results based on overall bud's weight.

But without discarding small differences of blue spectrum are behind the weight differences (we do not have enough data to do it), attending to how experiment was done, it not seem as a clear explanation neither. A weak hypothesis, IMHO

[oldmac]

Hey kanna,

Glad to see you, and still following the various lighting threads here. Your input is always intelligent and insightfull.

Hello clongo,

I appreciate your input, but I don't think that blue light explains the difference's here. BTW, you are not the first to mention the blue light effect.

As knna pointed out, the reason I used regular 23w CFLs at the start in 2 chambers was to off set the fact that the UVb bulb used was a CFL of 20w and would put out blue. I was also trying to keep the amount of total light energy the plants recieved equal. But during veg, the one chamber with UVb the bulb was bare, while the other chambers had the CFLs inside the boroscilicate glass tubes to insure no UVb, but they would see the blue. And again when the one chamber used for UVb flowering, that UVb bulb was bare while the control chamber had it's CFL still in the glass. All three chambers saw about equal levels of blue light. My only conclusion was the effect's seen were due to UVb and not blue.

While on the subject of blue light, you mentioned it's time factor. Could you explain what time factor is about or steer me to some source dealing in various light wavelenghts and thier time factors? It could maybe help me to better understand the PAD Manual and the Rauber theroy.

BTW as to amber trichomes, I agree that some people don't like the couch lock effect but in alot of cases with providing medicine to sick/dying people it helps with thier sleep. It's also why I have been growing the heck out of a plant I call "apricot" I used in this experiment; this plant will just not produce many trichomes let alone amber ones. It will stimulate appetite, ease pain and help with nausea but no matter how much is vaped/smoked it is a very mild high. Seems to work great for patients who are undergoing cancer treatments but are not looking to get high.

OM

[khyberkitsune]

"But without discarding small differences of blue spectrum are behind the weight differences (we do not have enough data to do it), attending to how experiment was done, it not seem as a clear explanation neither. A weak hypothesis, IMHO"

Blue is heavily responsible for weight production in a huge majority of terrestrial plants. My company has tested this over and over again, from vegetative crops to fruiting crops. The hypothesis is nowhere near 'weak' and in fact could pretty easily be demonstrated to be fairly accurate with my current system setup. All I would need would be a typical 7:1:1 tri-band panel of equal power to one of mine, set up a divider between the six channels I have, and hang a light over each set of three.

As for UVB increasing potency, John Lydon already performed this experiment with far better equipment and resources than any of us have back in 1987, and he clearly demonstrated a linear increase in THC production in drug-type cannabis using UVB at approximately 290nm.

And that particular experiment was his Ph.D thesis, which was accepted and what granted him his doctorate.