Rocket Soul
Well-Known Member
So youve havent tried it yourself?
Is far red dead
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driver77
Well-Known Member
I recently added uva/ir bars to my grows and saw a very noticeable improvement in growth and plant health. I would recommend anyone who hasn't tried it to try .....the proof will unfold in front of your eyes. Harder to prove or put a finger on but seems stronger and more aromatic when uva/ir are in the grow also.
Prawn Connery
Well-Known Member
Can we see the results of your tests? Surely if it's "snake oil" then you have proven this?
Should we ask the sun not to shine any UV on our outdoor plants? Because after all, it's "snake oil".
BTW, you're the guy who doesn't know the difference between "Far Red" and "Infra-red" light, right? Do you know the difference between UVC, UVB and UVA?
amneziaHaze
Well-Known Member
Just because it exists in nature doesnt mean its good for you.as it was proven it only destroys cell walls.
You know who proved uv was good those people that got sponsored by corporations that sell it.not a single paper on it beeing good unless its sponosred by them.
When you do a proper test call me.your test now was like using a 300w blurple and a 300w spiderfarmer and saying o yea its all just because of 1% uv nothing more.dont watch the spectrums. You sell lamps and you used someother persons lamp to do the test.use your own lamps just add your 1% what is that 2 lamps 3v you dont even need to build anything jam a flat battery between the contacts
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Prawn Connery
Well-Known Member
Then show us. Show us exactly who has tested UVA vs UVB vs no UV – other than myself and other growers who have agreed to the tests we've published.
If UVA "only destroys cell walls" – as you state – then there would be no life on this planet!
I can't help it if you can't read. I've literally shown you the spectra we used in the other thread here: https://www.rollitup.org/t/latest-uva-vs-uvb-cannabinoid-test-results.1052083/page-9#post-17424156amneziaHaze said:
If you were a reasonable person with a reasonable argument, I would quite happily discuss all this with you in a reasonable manner. But you bring nothing to the table and your posts don't even make sense half the time because you don't seem to understand even the basics, like the difference between UVA and UVB or Far Red and Infrared.
What are you trying to say? That you don't like UVA because you don't understand it? Because that's how it appears to me.
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Rocket Soul
Well-Known Member
This was our experience as well so far in our own tests. Plus plants being more hardy, not as easy to burn or light bleach. But the main take away was how easy it was to see that there had been some kind of effect: all plants with uv looked much better than all previous runs without; plant stance, color etc. And even more difference between uva and uva +uvb side, when introducing uvb in small portions; 30 mins (too much to start with) gave a shitty looking plant stance while 5 mins per hour gave a great looking plant.
AH; while its somewhat reasonable to nurse a bit of doubt regarding company sponsored studies the results presented by prawn and GLA are not without merit.
While i can see problems in the methodology in comparison with a proper peer-reviewed publications the spectrum differences are not really a big concern to me, they may not be perfect conditions but they still tell something. You never mention anything regarding the maths behind (which granted are somewhat missing in the GLA results) ; means, deviation from means, T-test and p-interval; this would to me be the real argument against the results; they've not been shown to be statistically relevant. Yet your approach to refute them never mentions this. Sorry, but failing to see the most obvious missing parts of prawns/GLAs study, while grasping for arguments regarding spectrum conditions; it makes your approach to arguing your point look wackamole-ish: just reaching for the next thing that can refute the other sides argument, whatever they may be. If youve already decided that the other side is wrong no matter what proof they bring youre being intellectually dishonest, not arguing in good faith.
Seems like youd prefer to be a "peer disprover" rather than a "peer reviewer"; be glad you can be part of the discussion of the results discussing them here, its an opportunity you never had with the peer reviewed studies youve seen online. Arguments regarding damaged cell walls etc; i dont think they suppose such a firm proof of uv decreasing plant health. Make the comparison with humans: intense weight lifting will cause some damage to muscle tissue and will raise indicators of inflammation. But its a long stretch to say this shows weightlifting/exercise is bad for your health.
amneziaHaze
Well-Known Member
Soo uvb was worst. Sample c was 870w sample d was 900w or other way around.sample a and b is kept quiet. One is made with 2 lamps one with 1...something was picket too soon. Great reaserch
Allsoo you state 12h is too much but 30min would be great.but lamps you sell dont have a switch for uv
but i will read it fully when i get home. Allsoo provide you with the university reaserch for why uv is shit.
And correct me if i am wrong but your control light was a mh lamp that produces uv?
Most of the reaserch that i read yeld less.maybe it wasjust uvb and not uva but i am 100% uvb and c are not good for growing
Allsoo you state 12h is too much but 30min would be great.but lamps you sell dont have a switch for uv
but i will read it fully when i get home. Allsoo provide you with the university reaserch for why uv is shit.
And correct me if i am wrong but your control light was a mh lamp that produces uv?
Most of the reaserch that i read yeld less.maybe it wasjust uvb and not uva but i am 100% uvb and c are not good for growing
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Rocket Soul
Well-Known Member
Im not sure if no you direct this to me or prawn, you mention 30 mins being ok but 12 hours not; im not sure if youre mixing up people or what i said as i said 30 mins of uvb was too much for unhardened plants, starting out with 5 mins per hour over the midday hours seem ok and we could make increases in 5 min every 3 days or so, currently at 15mins per hour during the 4 midday hours. However this is far from being the same as the GLA boards (12 hours on as no separate channel); they use 400nm near uv which is very different; i can confirm that this doesnt hurt the plant in any obvious and observable way from own experiments as we leave the uva on all day, it even has a bit of 365nm diodes in it.
Could you please post whatever papers that made you so sure about uvb being hurtfull to plants? It would be nice to check the details. I give no pushback on UVC, its harmfull.
Also worth mentioning we use 295nm diodes, i know a fair bit of studying uvb has been done with 280-285nm diodes which are very close to uvc.
My best guess is that a tapered approach to uv seems to work but might be hard to study formally: if youre making a research paper you have to be able to nail down conditions and method tightly; an increase uv exposure according to plant health approach introduce subjective criteria as the gardener must determine what is good plant health and how much is enough; all of this would be a no no in research. But this might actually be the right way to do it and if you only focus on studies which dont take into account this you may not tind any support for uv use even though there is a positive influence.
The other part of the tapered approach we use is to have the uv intensity levels taper off the further down into the uv we get: more 450 blue than uva 400, more uva 400 than uva 365, more uva than uvb, so that the slope of spectrum of the bluer end imitates what we see in sun light.
Edit: also maybe taking this discussion to a uv thread, this one is about far red.
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Prawn Connery
Well-Known Member
I believe that reply was intended for me. The fact he *thinks* I am saying different things when I suggest anywhere from 30 minutes to 4 hours to 12 hours of UV a day is because he doesn't know the difference between the different UV wavelengths.
High UVA (such as our Hight Lights with 405nm diodes) can run 12 hours non-stop.
Low UVA (~365nm) I would suggest 4-6 hours a day
UVB (<310nm) I would suggest 30mins to 1 hour a day tops.
However – as with everything – it will depend on other factors. But the bottom line is UVB may stimulate secondary metabolite production, but it also degrades (oxidises) cannabinoids at the same time. Sunlight only ramps up the UVB in the middle of the day for a few hours (at most) so the plant has time to recover from exposure. Plants can also go through physical changes – such as disperasion of chloroplasts, leaf cupping and pointing – during this period to reduce the amount of exposure.
He also needs to read our tests again, because we used the same lights in most casese with and without the addition of different UV sources, including reptile bulbs, metal halide and UVA LEDs.
High UVA (such as our Hight Lights with 405nm diodes) can run 12 hours non-stop.
Low UVA (~365nm) I would suggest 4-6 hours a day
UVB (<310nm) I would suggest 30mins to 1 hour a day tops.
However – as with everything – it will depend on other factors. But the bottom line is UVB may stimulate secondary metabolite production, but it also degrades (oxidises) cannabinoids at the same time. Sunlight only ramps up the UVB in the middle of the day for a few hours (at most) so the plant has time to recover from exposure. Plants can also go through physical changes – such as disperasion of chloroplasts, leaf cupping and pointing – during this period to reduce the amount of exposure.
He also needs to read our tests again, because we used the same lights in most casese with and without the addition of different UV sources, including reptile bulbs, metal halide and UVA LEDs.
Prawn Connery
Well-Known Member
We have never claimed our tests are laboratory controlled, peer-reviewed studies. Growing cannabis is still illegal in Australia and so we do the best we can to standardise things.
To emphasise how dangerous it is, we have already lost access to our regular cannabinoid tester because he was busted and all his equipment (tens of thousands of dollars worth) was seized.
What I can say is that a lot of the so-called "control" grows we have seen in scientific papers have left a lot to be desired. The Llewellyn tests were covered in powdery mildew and their methodology was also piecemeal. Bugbee also appears to blow with the wind and seems to change his mind about UV but he's growing CBD plants anyway, so he hasn't done any real tests on high-THC plants.
The growers we use are good growers. I have to include myself in that, because I've been growing indoors for well over 20 years and outdoors prior to that. Some of our guys have been doing it even longer – almost 40 years in one case. We all have good experience growing cannabis. I can't say the same for some of these scientists, but no-one ever mentions the fact they might be good scientists but pretty average growers. Just sayin'
To emphasise how dangerous it is, we have already lost access to our regular cannabinoid tester because he was busted and all his equipment (tens of thousands of dollars worth) was seized.
What I can say is that a lot of the so-called "control" grows we have seen in scientific papers have left a lot to be desired. The Llewellyn tests were covered in powdery mildew and their methodology was also piecemeal. Bugbee also appears to blow with the wind and seems to change his mind about UV but he's growing CBD plants anyway, so he hasn't done any real tests on high-THC plants.
The growers we use are good growers. I have to include myself in that, because I've been growing indoors for well over 20 years and outdoors prior to that. Some of our guys have been doing it even longer – almost 40 years in one case. We all have good experience growing cannabis. I can't say the same for some of these scientists, but no-one ever mentions the fact they might be good scientists but pretty average growers. Just sayin'
Rocket Soul
Well-Known Member
This is also why in asking AH for the studies hes talking about.
Regarding statistical significance; sorry i hope i didnt offend you. Normally when you run this kind of studies for science youre generally not looking at a higher/lower value as an end result, its a data point part of a set that you run some statistical analysis on. In this case you could for example take samples from all plants in the study of each light, test them for thc numbers, find mean and standard deviation and run a t-test. Its a test which calculates the chance that the difference in values between different set conditions (no uv, uva, full uv for example) really are different due to the set conditions and not just due to a statistical fluke.
However testing every plant is obviously very costly, its only really something that is accessible if you have real money behind, such as a large light manufacturer; but then again if it was a large light manufacturer there may be bias due to that if we follow AHs argument. Damned if i do damned if i dont...
Personally im very happy and convinced re your tests and i think you provide a service to the community; not only the info but also your part in getting some of these boards designed.
Id argue that you are infact peer reviewed; its nor done by perfect scientists nor reviewed by perfect scientists so yeah, peers...
Im convinced that there is enough meat on this bone to try all the way down to uvb
hillbill
Well-Known Member
I remember that scene in your Avatar. Woodstock 69, that guy is about to rock out to Joe Coker!
amneziaHaze
Well-Known Member
Cannabis Inflorescence Yield and Cannabinoid Concentration Are Not Increased With Exposure to Short-Wavelength Ultraviolet-B Radiation
Before ultraviolet (UV) radiation can be used as a horticultural management tool in commercial Cannabis sativa (cannabis) production, the effects of UV on cannabis should be vetted scientifically. In this study we investigated the effects of UV exposure ...
doesnt talk about yeld but tells how a plant will be stunted and its photosynthesis affected https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8408258/
you might be right about UVA i havent been able to find anything bad about it.
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Prawn Connery
Well-Known Member
Actually, it appears to say the exact opposite. Net photosynthesis is INCREASED . . . but like a lot of things, it is dosage and species dependent.Cannabis Inflorescence Yield and Cannabinoid Concentration Are Not Increased With Exposure to Short-Wavelength Ultraviolet-B Radiation
Before ultraviolet (UV) radiation can be used as a horticultural management tool in commercial Cannabis sativa (cannabis) production, the effects of UV on cannabis should be vetted scientifically. In this study we investigated the effects of UV exposure ...www.ncbi.nlm.nih.gov
doesnt talk about yeld but tells how a plant will be stunted and its photosynthesis affected https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8408258/
We already know there is a trade-off between the blue-violet-UV end of the spectrum and the red end of the spectrum in terms of yield but one of the reasons we did our tests was to see how UVA behaves in the presence of Far Red. We know Far Red is responsible for cell expansion and blue/violet for cell contraction, but there are very few LED grow lights out there that are "truely" full-spectrum and cover both ends. You will note that all the lights we used for our tests contained quite high levels of Far Red – between 5% and 10%.
You are right about one thing: UV should not be tested in isolation because it appears other spectra can influence its morphlogical response.
Also, some people forget that UVR8 pigments absorb photons in the UVA/violet/blue range but that an exponential number of them (photons) is required for the same response as UVB photons around 280nm.
Prawn Connery
Well-Known Member
No offence taken mate. I realise more than anyone the limitations of what we did, however I will say one thing, and that is the trend was the same throughout all the tests we did. Yes, there may have been statistical margins of error, but when you see the same trend every time you do the same experiments or variations thereof, you start to reach certain conclusions.This is also why in asking AH for the studies hes talking about.
Regarding statistical significance; sorry i hope i didnt offend you. Normally when you run this kind of studies for science youre generally not looking at a higher/lower value as an end result, its a data point part of a set that you run some statistical analysis on. In this case you could for example take samples from all plants in the study of each light, test them for thc numbers, find mean and standard deviation and run a t-test. Its a test which calculates the chance that the difference in values between different set conditions (no uv, uva, full uv for example) really are different due to the set conditions and not just due to a statistical fluke.
However testing every plant is obviously very costly, its only really something that is accessible if you have real money behind, such as a large light manufacturer; but then again if it was a large light manufacturer there may be bias due to that if we follow AHs argument. Damned if i do damned if i dont...
Personally im very happy and convinced re your tests and i think you provide a service to the community; not only the info but also your part in getting some of these boards designed.
Id argue that you are infact peer reviewed; its nor done by perfect scientists nor reviewed by perfect scientists so yeah, peers...
Im convinced that there is enough meat on this bone to try all the way down to uvb
And at the end of the day the proof is in the pudding: our lights work and we don't get any complaints.
amneziaHaze
Well-Known Member
this photo says increased photosyntesis but closed stomata.sounds strange and all the reproductives are in the negative and thats all what we want from cannabis....
Prawn Connery
Well-Known Member
I don't doubt UVB has a negative effect on photosynthesis . . . at much higher rates, which is what the study says:
In other words, there are risks to making blanket statements about UV without putting it into the right context.
EDIT: But we could also read that graphic stating "net photosynthesis" as increasing photosynthetic efficiency even as stomata are closed. Or in other words, total photosynthesis falls, but net photosynthesis in relation to the number of moles (and/or combined energy thereof) of photons needed to convert each mole of CO2 to glucose reduces.
In other words, there are risks to making blanket statements about UV without putting it into the right context.
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amneziaHaze
Well-Known Member
6W m2 and how much watts did you use in your study?
Prawn Connery
Well-Known Member
I will need to look that up as it was some time ago. But regardless, 6W of 280nm photons will have a much, much stronger UVR8 response than 6W of 400nm photons, as you can see in the absorption graph above.
To put it into perspective, compare 6W per square meter of 280nm UVB to 6Wm2 of broad-spectrum PAR (400-700nm) which does not stress plants at all – even shade varieties that are very susceptible to light burn.
Our current lights have 1% UVA from around 385-400nm and we have seen no ill effects at all. Quite the contrary. And let's not forget that ~400nm is also very photosynthetically active.
cdgmoney250
Well-Known Member
A fun and easy read about Far Red from Fluence…
fluence-led.com
FAR-RED: INTRODUCTION AND YIELD
Far-red refers to wavelengths of light between 700 and 800 nm. This falls just outside the range of visible light for humans and what is traditionally considered “photosynthetically active radiation” (PAR) for plants.
fluence-led.com