Or_Gro and the epic smackdown

[Frank Cannon]

OG, what type and size of dehumidifier do you use? 2ndly how noisy are they?

Prawn do you think I need to worry about our current night time humidities in the last few weeks of flower? I am wondering if I should run lights on during the night for last 4 weeks of bloom?
FC

[Rocket Soul]

Hail Hail the gang's all here!

What happened at Riu, Or-gro? Im a bit of a gossip, is it in your thread? I never had a run in with the mods and i avoid the trolls but not really happy with the state generally.

I predict a High light win. Great spectrum with great distribution (boards covering around half of the cannopy!) is the ticket imho.

Welcome dude!

I had a thread going about the very inexpensive, but effective, donut humidifiers. The troll mongo frog, and his buds/alternate handles showed up and did their troll dance. I politely asked them to leave, AND took prawn’s advice to use humor to get rid of them. I didn’t even curse, tho i did tell one of them to go fondle himself.

I reported them for harassment, and Later that day, my thread was disappeared and the mf’s slowed me down so much that each time i tried to post i timed out before i could post.

This was the 3rd time this guy and his posse have attacked my threads, unprovoked. The same guy trolled prawn and randomblame, and apparently got teknik exiled. He has been a member for 10 years, doing this crap, and they just let him continue.

I said f it, no more. I don't suffer trolls, but more importantly, i don’t participate in forums where trolls are treated better than thread starters.

Riu has some great experts, and lots of good people, but shitty admin. I will never post there again.

Ok, sounds familiar. Sorry i even mentioned it. Anyways, on with the grow-off, this one should be a treat. I make a point out of showing your stuff to my growbuddy cause it rocks his world on whats possible. Told me impossible about the last smack down, took one look at your grow and admits, "yeah, its there". Going to be doing a new setup after summer and since we probably cant get anything comparable in cannopy size as the last one, so this is inspiration.

[Prawn Connery]

On 280ish / 360ish UV: theres some info if you google stomata aperture action spectrum (cant remember which one and no time to double check). They talk about the "3-finger action spectrum with several peaks, 280 / 360 being 2 of them. Granted its not cannabinoides but usually nature follows down the same paths.
Theres also info if you look up uvr8 (gene? Receptor? Random knows as usual...)

If this was already posted then sorry, havent caught up on the whole thread.

That would be this study into the UV action spectra, yes? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC58848/

But that's only a study into stomatal opening response to different wavelengths - not cannabinoid production. You did mention that, of course. And we know that secondary metabolite production as a defence mechanism is triggered by light saturation. So obviously, the more sensitive a pigment is to light, the sooner it is saturated, and the sooner the defence mechanism is triggered. That would be one assumption.

UVR8 activation (by UVB) as a catalyst to cannabinoid precursor chemicals is explained here: https://www.maximumyield.com/uvb-a-crit ... is/2/17478

The Max Yield article doesn't mention that UVR8 is most sensitive at 285nm, but that is the case.

All good so far. The article also mentions the Maryland study that found a 33% increase in THC when the plant was exposed to 385nm, but no corresponding increase in CBD (in fact, no increase in CBD at all).

So it appears THC levels can be increased through UVA alone, but CBD levels are influenced (apart from genetics) mostly by UVB levels. That is, if we draw this conclusion from the above studies.

What is interesting about the first study is that, yes the 280nm response is 2.5x that of 420nm, but 420nm is 2.5x more responsive than 360nm - meaning 420nm is more efficient at regulating stomata than 360nm. (Also, if you read the study, the 285nm response is linked to the 459nm response - when either of those pigments are saturated, it doesn't increase photosynthesis by targetting the other one.)

However, if you go to yet another study, you discover that two LED samples produced higher levels of cannabinoids than HPS, even though HPS produced higher yields: https://www.karger.com/Article/Fulltext/489030

The kicker is that in this ^ study, the total amount of cannabinoids produced by all forms of light was the same! That is to say, HPS had lower levels of THC, but higher plant yields; LED had lower plant yields, but higher THC levels.

Does this mean that when a plant switches from primary metabolites (growth) to secondary (terpenoids), there is an equal trade-off? Well, the study seems to point to that . . .

But what I find most interesting is the LED sample that produced the highest THC, CBD and overall cannabinoid levels had a small amount of UVA, but the highest amount of blue (400-500nm). The highest yielding light with the lowest cannabinoids (HPS) also had a small amount of UVA, but the lowest amount of blue.

Have a look at the spectrum of NS1 - the highest cannabinoid producing LED light:


Look at that nice little bump around 405nm. And look at all the deep red. Kinda reminds me of this, LOL! (The original High Light spectrum)

original.png (33.62 KiB) Viewed 1003 times

It appears the shorter blue wavelengths - likely including UVA - inhibit plant growth, but stimulate secondary metabolites, possibly as a defence against the higher amounts of radiant energy.

So what are we to conclude? That 285nm appears to be the most efficient way to stimulate cannabinoid production - but is also potentially the most damaging to plant DNA and detrimental to primary metabolism - and that 360-385nm UVA produces more THC, but not more CBD, however can probably be compensated for by high frequency blue around 420nm which does appear to also target CBD - much like 285nm, which apparently triggers the same receptors/pigments as blue between 420 and 459nm (which have similar responses).

That's not gospel of course, but it's what I'm reading into all of this.

[Rocket Soul]

Lol, i can see im preaching to the choir. Im pretty sure its that study i was talking about but i dont quite recognize the format. I sat down a month or so ago and just had a good read on several studies but sometimes im a bit sloppy and i dont quite remember. I had something with smaller print (of course my brain works like the smaller the print the more scientific and valuable the information ;p )

My whole point was that nature seems to reuse its ideas and functions in life: light therapy in humans is focused on 660nm and far red which seems to be the most potent, same as in plants. If it opens the stomata its bound to do something else aswell, or at least its an educated guess until we actually know different. Personally i think rather than pinpointing frequencies like a scalpel there might be a point making sure nothing is missing: broad blue/uv spread without it getting too much to draw down yield too much. Cmh has served us really well, seems like they allways outdo their on paper spec, and they feature this broad sunlike spectrum, from uv to ir. But it wont beat our best led yields but im not sure if this has more to do with light distribution which bulbs arent that good for. But cmh sure makes for an easy, no finicky grow, almost on autopilot in comparison to led.

[Rocket Soul]

Also, just throwing this out there: if this was more about science of spectrum rather than seeing what setup maximizes your grow with big sticky buds then there might be a point in doing these side by sides on lower intensity, where differences in spectrum should be more obvious. But noone is paying us to science for them and theres no point in leaving weight on the tray just because.

Anyways happy to see all of this

[Prawn Connery]

OG, what type and size of dehumidifier do you use? 2ndly how noisy are they?

Prawn do you think I need to worry about our current night time humidities in the last few weeks of flower? I am wondering if I should run lights on during the night for last 4 weeks of bloom?
FC

You can, but your best defence against mold is air movement. If you have a lot of air movement, mold spores can't take hold. The most humid time of the day is usually just before dawn, so you could hedge your bets and have your lights on from, say 4-5am to 4-5pm, but it is more important to have a good fan blowing through the canopy.

[Prawn Connery]

Lol, i can see im preaching to the choir. Im pretty sure its that study i was talking about but i dont quite recognize the format. I sat down a month or so ago and just had a good read on several studies but sometimes im a bit sloppy and i dont quite remember. I had something with smaller print (of course my brain works like the smaller the print the more scientific and valuable the information ;p )

My whole point was that nature seems to reuse its ideas and functions in life: light therapy in humans is focused on 660nm and far red which seems to be the most potent, same as in plants. If it opens the stomata its bound to do something else aswell, or at least its an educated guess until we actually know different. Personally i think rather than pinpointing frequencies like a scalpel there might be a point making sure nothing is missing: broad blue/uv spread without it getting too much to draw down yield too much. Cmh has served us really well, seems like they allways outdo their on paper spec, and they feature this broad sunlike spectrum, from uv to ir. But it wont beat our best led yields but im not sure if this has more to do with light distribution which bulbs arent that good for. But cmh sure makes for an easy, no finicky grow, almost on autopilot in comparison to led.

I tend to agree. There's a lot of guess-work out there and very limited studies into cannabinoid production - some if it contradictory. It would seem the more you can "fill in the gaps" - as with natural sunlight - the more chance there is of not missing something, even if we don't fully understand it.

Having said that, there are things we know that work in terms of yield and plant health that apply to a broad range of species, such as red light driving plant mass and excess blue light impacting yield, so there are still some basic guidelines we can use as we continue to make new discoveries.

[unkle_psycho]

Hail Hail the gang's all here!

What happened at Riu, Or-gro? Im a bit of a gossip, is it in your thread? I never had a run in with the mods and i avoid the trolls but not really happy with the state generally.

I predict a High light win. Great spectrum with great distribution (boards covering around half of the cannopy!) is the ticket imho.

Welcome dude!

I had a thread going about the very inexpensive, but effective, donut humidifiers. The troll mongo frog, and his buds/alternate handles showed up and did their troll dance. I politely asked them to leave, AND took prawn’s advice to use humor to get rid of them. I didn’t even curse, tho i did tell one of them to go fondle himself.

I reported them for harassment, and Later that day, my thread was disappeared and the mf’s slowed me down so much that each time i tried to post i timed out before i could post.

This was the 3rd time this guy and his posse have attacked my threads, unprovoked. The same guy trolled prawn and randomblame, and apparently got teknik exiled. He has been a member for 10 years, doing this crap, and they just let him continue.

I said f it, no more. I don't suffer trolls, but more importantly, i don’t participate in forums where trolls are treated better than thread starters.

Riu has some great experts, and lots of good people, but shitty admin. I will never post there again.

Never registered in RIU. While reading posts there I would continously see well behaving people silenced just because their area of interest somehow threatened a sponsor or was perceived as having market potential. This spills into a weired mentality where packs hunt and interrogate content providers.

They seem to try to present rational arguments to justify and mask their behavior. A troll army attacks the person creating content, then the content provider is framed as having attitude for defending their work. The general level of trolling allowed shows they have no real interest in promoting good behavior.

It's really a pity that the gurus in RIU don't realize that without them the site is nothing. I find it disgusting how the openness and good will of the cannabis community could be so perverted and leveraged to create one of the most oppressive forum formats I've seen in a long life.
When commies create caricatures of capitalists being fat lazy bastards living of others labor I giggle, but RIU is actually a very pure example of these types of mechanics in action.

I definitely won't tell anyone what to do, but for me this is one of those areas where I vote with my feet, to do my little part in creating a world I can believe in. Life has been a little slow in the ledgardner village, but quite pleasant.

[unkle_psycho]

What's up guys, just thought I'd pop in and say hi.

As for the "UVI vs UV measurement" ...

The unweighted UV measurement will always be a considerable amount more than the UVI × 25mW/m2. The UVI × 25mW/m2 is only the area under the created curve, you'd have to divide the created curve by the erythemal curve and then integrate from 280nm to 320nm to be able to compare apples to apples.


USER_SCOPED_TEMP_DATA_orca-image--2083017694.jpeg_1559517491818.jpeg
The UVI curve (*) is created by multiplying the erythemal curve (*) by the actual radiation curve (*, actual SPD curve) for every nm of WV from 295 to 400 (I think it's all the way to 400nm). So its multiplying the lights individual WV intensity at 295 by 100%, 296nm at 93%, 297nm at 87%, 298nm at 80% 299nm at 74%, ect ect. all the way till 400nm. It's just multiplying the actual SPD by the erythemal to create a UVI curve that's further integrated and divided by 25mW/m2 for a final UVI.

At ~309nm the erythemal weighting has already diminished to ~10% with 295nm being 100%. So if your UVB meter is reading 800μW/cm2, you have to remember that barely any of that is <296nm, and at 309nm you're only about 10% weight, let alone 1% at 319nm. The 800μW/cm2 is being recorded unweighted and the majority of that unweighted emmission recording is primarily from 320nm due to the SPD of the bulb, so the total reading should be much greater than the weighted reading.


debilt20020601.gif
^^^The yellow portion is the UVI index that still needs to be divided by 25 to achieve a UVI. The area under the "measured" spectrum from 280nm to 320nm is the total quantity of UVB that your UVB meters will pick up...


Ill have to check out the video, sounds interesting.

Hmm... I feel if I look at this long enough I might get smarter

[unkle_psycho]

On 280ish / 360ish UV: theres some info if you google stomata aperture action spectrum (cant remember which one and no time to double check). They talk about the "3-finger action spectrum with several peaks, 280 / 360 being 2 of them. Granted its not cannabinoides but usually nature follows down the same paths.
Theres also info if you look up uvr8 (gene? Receptor? Random knows as usual...)

If this was already posted then sorry, havent caught up on the whole thread.

That would be this study into the UV action spectra, yes? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC58848/

But that's only a study into stomatal opening response to different wavelengths - not cannabinoid production. You did mention that, of course. And we know that secondary metabolite production as a defence mechanism is triggered by light saturation. So obviously, the more sensitive a pigment is to light, the sooner it is saturated, and the sooner the defence mechanism is triggered. That would be one assumption.

UVR8 activation (by UVB) as a catalyst to cannabinoid precursor chemicals is explained here: https://www.maximumyield.com/uvb-a-crit ... is/2/17478

The Max Yield article doesn't mention that UVR8 is most sensitive at 285nm, but that is the case.

All good so far. The article also mentions the Maryland study that found a 33% increase in THC when the plant was exposed to 385nm, but no corresponding increase in CBD (in fact, no increase in CBD at all).

So it appears THC levels can be increased through UVA alone, but CBD levels are influenced (apart from genetics) mostly by UVB levels. That is, if we draw this conclusion from the above studies.

What is interesting about the first study is that, yes the 280nm response is 2.5x that of 420nm, but 420nm is 2.5x more responsive than 360nm - meaning 420nm is more efficient at regulating stomata than 360nm. (Also, if you read the study, the 285nm response is linked to the 459nm response - when either of those pigments are saturated, it doesn't increase photosynthesis by targetting the other one.)

However, if you go to yet another study, you discover that two LED samples produced higher levels of cannabinoids than HPS, even though HPS produced higher yields: https://www.karger.com/Article/Fulltext/489030

The kicker is that in this ^ study, the total amount of cannabinoids produced by all forms of light was the same! That is to say, HPS had lower levels of THC, but higher plant yields; LED had lower plant yields, but higher THC levels.

Does this mean that when a plant switches from primary metabolites (growth) to secondary (terpenoids), there is an equal trade-off? Well, the study seems to point to that . . .

But what I find most interesting is the LED sample that produced the highest THC, CBD and overall cannabinoid levels had a small amount of UVA, but the highest amount of blue (400-500nm). The highest yielding light with the lowest cannabinoids (HPS) also had a small amount of UVA, but the lowest amount of blue.

Have a look at the spectrum of NS1 - the highest cannabinoid producing LED light:


Look at that nice little bump around 405nm. And look at all the deep red. Kinda reminds me of this, LOL! (The original High Light spectrum)
original.png

It appears the shorter blue wavelengths - likely including UVA - inhibit plant growth, but stimulate secondary metabolites, possibly as a defence against the higher amounts of radiant energy.

So what are we to conclude? That 285nm appears to be the most efficient way to stimulate cannabinoid production - but is also potentially the most damaging to plant DNA and detrimental to primary metabolism - and that 360-385nm UVA produces more THC, but not more CBD, however can probably be compensated for by high frequency blue around 420nm which does appear to also target CBD - much like 285nm, which apparently triggers the same receptors/pigments as blue between 420 and 459nm (which have similar responses).

That's not gospel of course, but it's what I'm reading into all of this.

Did you see the UV video from Seoul? They were getting results with very low levels of 285nm. They claimed you need 10x more power at 310nm to get the same results.

Now that I'm talking to you, do you still have any of those prawn boards? I have been looking at different solutions for high CRI, and really like the effort you guys put into this. Were planning on doing some side by sides with different spectrums, and these boards would definitely fit in.

I guess delivery from down under to scandinavia might be a bit of a bitch?