Should I add UVB Light?

[Milson]

Man that's a nice ass-light. (XKCD)

What can you show us about your grows?

He has a great diary going called the shyre 1.5. lots of data.

 

[LaVirtue]

Really cool interview w solacure founder!

Industry Insider: Dennis Brown - Hydromag

Solacure’s UV light, The Flower Power, is a broadband UV bulb producing UVA and UVB light. Their lights have been show to bridge the gap in quality between garden grown tomatoes and those grown indoors, out of season. We caught up with Dennis Brown to give some insight into Solacure and the work...

hydromag.co.uk

View attachment 1105720

UVR8 - Wikipedia

en.wikipedia.org

View attachment 1105721

The purdue paper

Milsonmilson.me

This is going to be very interesting to watch

 

[Milson]

@Aqua Man , I was thinking about what you were saying with blue and an "emerson effect" w.r.t. THC and I had a flash to this paper about its changeover from producing CBGA to THCA.

Perhaps this is the mechanism for the blue effect and the UV effect is a separate mechanism? Or maybe not.

Worth a think though.

You can see the graphic below with levels for each across time on the X axis with three different lighting regimens. Those three regimens are A, B, and C and defined in the next screenshot.

This one here.

Then there is this table, which is another cool taste.

If anyone is interested in the whole paper, they can download it via the file linked at the end of this haiku. As you can see, it is out of Israel. @Moe.Red , this might be a cool thing to independently verify/test toward something similar at some point down the road as well.

Milsonmilson.me

 

[Aqua Man]

@Aqua Man , I was thinking about what you were saying with blue and an "emerson effect" w.r.t. THC and I had a flash to this paper about its changeover from producing CBGA to THCA.

Perhaps this is the mechanism for the blue effect and the UV effect is a separate mechanism? Or maybe not.

Worth a think though.

You can see the graphic below with levels for each across time on the X axis with three different lighting regimens. Those three regimens are A B and C and defined in the next screenshot.

View attachment 1106359
This one here. View attachment 1106357

Then there is this table, which is another cool taste.

View attachment 1106358

If anyone is interested in the whole paper, they can download it via the file linked at the end of this haiku. As you can see, it is out of Israel. @Moe.Red , this might be a cool thing to independently verify/test toward something similar at some point down the road as well.

View attachment 1106361

Milsonmilson.me

Would not surprise me one bit if it does

 

[Milson]

Following papers off the one I just posted.......


Ahhhhhhhh!!!!!!!




That is a free paper. It claims, among other things, to see a big uptick in CBG production when flowering under LED. Also has claims about UVA and UVB. It may be something that is related to what @Aqua Man was referring to. I may pull screenshots from it later but I am tired right now lol. But it is very cool.

Coming off doing some TLC testing on an old Widow back cross, seeing surprising levels of CBG and THCV, trying it with my father, and seeing preliminary evidence of a significant neuorlogical effect related to the movement disorder he suffers from (Parkinson's) that has not been present in THC-dominant strains he has tried so far (it isn't close, this effect was and is different in kind), that is of immense interest to me.

(it could also 100000% be a strain specific thing that has nothing/little to do with the lighting regimen I use....it's just, if the gene is there, I want to try to express it fully if I can help it along with choices beyond general plant happiness re feeding etc).

 

[Aqua Man]

Following papers off the one I just posted.......


Ahhhhhhhh!!!!!!!

Starting to get the same feeling I am about the blue and UVA/UVB combination?

 

[Milson]

Starting to get the same feeling I am about the blue and UVA/UVB combination?

Uva yes and quite strongly. I am not sure uvb is in the same camp though. Could be.

That paper is also just another gold mine of things to play with.

 

[Aqua Man]

There was a study yrs back... @MIMedGrower may have it. Testing mh vs hps at the same wattage for growth and the HPS was clearly producing larger buds... I can't remember the reason or conclusion they came to as to why but my opinion is that its 2 fold...

So if anyone didn't know light intensity measured in photons is the driving force for plant growth and the higher the photosynthetic rates the faster and more growth... spectrum plays more of a roll in the type of growth. Many assume red light grows bigger buds and while this may be true I think there is more than just spectrum but the missing part is...

The intensity..... so photons per watt play a big role as we see the ppfd go way up on the new leds and the yields along with it. Now red light is more efficient than than blue so more photons are pruduce with a red leaning spectrum like HPS in comparison to MH. That means more photosynthesis to a point. Now add to that plants photosynthesize red the most efficiently... so not only do you get more photons but also the plant is more efficient at using them than other spectrums. This difference I feel would not be as pronounced at higher intensity where the plants are closer to reaching saturation in each type of receptors which is why a full spectrum is better than blurples.

But with the new led fixtures intensity can still be maxed while supplying a more blue spectrum and while the structure may be different the weight doesn't seem to be.... thats the next race in lighting... maximizing intensity in the right ratios


Some facts and some opinions and some plain out speculation. So take with a grain of salt

 

[Milson]

There was a study yrs back... @MIMedGrower may have it. Testing mh vs hps at the same wattage for growth and the HPS was clearly producing larger buds... I can't remember the reason or conclusion they came to as to why but my opinion is that its 2 fold...

So if anyone didn't know light intensity measured in photons is the driving force for plant growth and the higher the photosynthetic rates the faster and more growth... spectrum plays more of a roll in the type of growth. Many assume red light grows bigger buds and while this may be true I think there is more than just spectrum but the missing part is...

The intensity..... so photons per watt play a big role as we see the ppfd go way up on the new leds and the yields along with it. Now red light is more efficient than than blue so more photons are pruduce with a red leaning spectrum like HPS in comparison to MH. That means more photosynthesis to a point. Now add to that plants photosynthesize red the most efficiently... so not only do you get more photons but also the plant is more efficient at using them than other spectrums. This difference I feel would not be as pronounced at higher intensity where the plants are closer to reaching saturation in each type of receptors which is why a full spectrum is better than blurples.

But with the new led fixtures intensity can still be maxed while supplying a more blue spectrum and while the structure may be different the weight doesn't seem to be.... thats the next race in lighting... maximizing intensity in the right ratios


Some facts and some opinions and some plain out speculation. So take with a grain of salt

Yeah, i think yield had been pretty well-studied and confirms that red heavy spectrums at even intensity produce more etc.

Study above also shows that. More dry weight. But it shows less cannabinoids, especially cbg.

Not saying that's gospel either. But it warrants to those so-inclined. Especially because if there are tradeoffs more in the interest of the home grower than the commercial producer, it might be nice to test for those to the best of our ability ourselves. Maybe someone else does it for me, maybe not. God knows I'm on the lookout.

 

[LaVirtue]

Following papers off the one I just posted.......


Ahhhhhhhh!!!!!!!




That is a free paper. It claims, among other things, to see a big uptick in CBG production when flowering under LED. Also has claims about UVA and UVB. It may be something that is related to what @Aqua Man was referring to. I may pull screenshots from it later but I am tired right now lol. But it is very cool.

Coming off doing some TLC testing on an old Widow back cross, seeing surprising levels of CBG and THCV, trying it with my father, and seeing preliminary evidence of a significant neuorlogical effect related to the movement disorder he suffers from (Parkinson's) that has not been present in THC-dominant strains he has tried so far (it isn't close, this effect was and is different in kind), that is of immense interest to me.

(it could also 100000% be a strain specific thing that has nothing/little to do with the lighting regimen I use....it's just, if the gene is there, I want to try to express it fully if I can help it along with choices beyond general plant happiness re feeding etc).

Holy crap, I just learned I don't have a clue. They are even using UVB on cotyledons. The whole last 2 weeks of flower comes seriously under question based on that paper.

I need to step back from this a minute and look at the big picture. Within this UV testing there are about a billion variables.

what a wonderful thing if it helps with Parkinson’s

 

[Moe.Red]

Study above also shows that. More dry weight. But it shows less cannabinoids, especially cbg.

I'm all about expressing the maximum of minor cannabinoids and terps given a specific genetic start. Since I have both LED and HID/HPS tents, this seems like something I could tackle with a group of clones, different light sources, and supplementals like the Far Red, UVA, and UVB light bars I have. We would just need to define the test.

If we had a clear result that CBG is higher in a clone grown under LED and UVA, or a similar result, I'd be really happy with that.

 

[shaganja]

Have been experimenting with agromax pure uv. I put them on 4 hours mid day last season in greenhouse. Was during veg, and flower. Did mid day hours to mimic high uv during that time. My grow went well. I just switched to no till regenerative. Very well actually. My bags are much more sandy than years before. Do I attribute it to the uv, or to the new grow style? Not sure. One thing I did notice is, i grew a cbd plant, Harley m.d. this plant came out no cbd. I can tell cbd immediately because of my brain injury. I don't even wanna smoke it, because she is more sativa feeling. Edgy, anxious. Not a cbd feeling buzz at all. Now, is she just an outlier? Or is she a result of uv light changing her cannabinoid expression? I think of the story of black beauty, or purple . started out as a cbd plant, but after using uv, she changed to a thcv carrier. If I had the space, I would for sure look further into this. Take a bunch of cbd plants, and run em with uvb through veg, and flower. And maybe do another with uv only at the end. This year, in the greenhouse, am only turning them on, end of flower. See how it goes.

 

[Milson]

Have been experimenting with agromax pure uv. I put them on 4 hours mid day last season in greenhouse. Was during veg, and flower. Did mid day hours to mimic high uv during that time. My grow went well. I just switched to no till regenerative. Very well actually. My bags are much more sandy than years before. Do I attribute it to the uv, or to the new grow style? Not sure. One thing I did notice is, i grew a cbd plant, Harley m.d. this plant came out no cbd. I can tell cbd immediately because of my brain injury. I don't even wanna smoke it, because she is more sativa feeling. Edgy, anxious. Not a cbd feeling buzz at all. Now, is she just an outlier? Or is she a result of uv light changing her cannabinoid expression? I think of the story of black beauty, or purple . started out as a cbd plant, but after using uv, she changed to a thcv carrier. If I had the space, I would for sure look further into this. Take a bunch of cbd plants, and run em with uvb through veg, and flower. And maybe do another with uv only at the end. This year, in the greenhouse, am only turning them on, end of flower. See how it goes.

That is super interesting! What does the plant smell like? How high above the canopy were you running the bulbs?

 

[shaganja]

She doesn't smell very good at all. Like middies. No smells are dominate. That cbd cherry smell just barely. Just smells like cheap mids. I for sure ran them too close. 2ft. Had to lst, because uv was doing damage. This year putting them at least 3 ft. Away.

 

[Moe.Red]

Guessing this is the paper in question. Improvement appears to top out at 32 percent in floral tissues and they make copious mention of flavonoids, which rings true if you have ever run uvb.

I'm sorry these are so tall.
View attachment 1093800View attachment 1093801View attachment 1093802View attachment 1093803View attachment 1093804

OK @Milson

I'm an idiot savant, hold the savant.

I have read this paper on the screen. Things didn't add up, so I printed it out for some bedtime reading. Still a couple of WTFs so I took it to the desk and started highlighting. Turns out yellow ink over the sentences does not add any clarity.

The first thing that throws me off is they are talking about irradiating plants that are 11 months old, 13 months old, etc. From early veg thru flower. Are they smoking this stuff or growing it? Is it even possible to have a 13 month plant in flower, and if so, are we not talking about something vastly different than what we experience in our home grows? 4 months is a long time from seed to harvest for me, I can't imagine the husbandry it would take to keep a plant healthy in flower for a year.

Then throw in statements like this:

Vegetative or flowering plants were exposed to UV-B radiation for 30 days prior to the start of the experiment. At that time, plants were trimmed to a uniform height. Vegetative and floral meristems developed while plants were irradiated for an additional 40 days.

Meristems are weed's version of stem cells - just saving people some googling.

Like I said, idiot hold the savant, but I just don't see how this test was run.

What am I missing?

I did find some of the parts about growing at altitude interesting, something I have seen you comment on before. I can't wrap my brain around why that would be tho, other than the obvious VPD and respiration effects - which in my mind would effect plant size more than cannabinoid content, and the fact that UV is stronger when it has less atmosphere to pass thru.

And words of wisdom for me?

 

[Milson]

OK @Milson

I'm an idiot savant, hold the savant.

I have read this paper on the screen. Things didn't add up, so I printed it out for some bedtime reading. Still a couple of WTFs so I took it to the desk and started highlighting. Turns out yellow ink over the sentences does not add any clarity.

The first thing that throws me off is they are talking about irradiating plants that are 11 months old, 13 months old, etc. From early veg thru flower. Are they smoking this stuff or growing it? Is it even possible to have a 13 month plant in flower, and if so, are we not talking about something vastly different than what we experience in our home grows? 4 months is a long time from seed to harvest for me, I can't imagine the husbandry it would take to keep a plant healthy in flower for a year.

Then throw in statements like this:

Vegetative or flowering plants were exposed to UV-B radiation for 30 days prior to the start of the experiment. At that time, plants were trimmed to a uniform height. Vegetative and floral meristems developed while plants were irradiated for an additional 40 days.

Meristems are weed's version of stem cells - just saving people some googling.

Like I said, idiot hold the savant, but I just don't see how this test was run.

What am I missing?

I did find some of the parts about growing at altitude interesting, something I have seen you comment on before. I can't wrap my brain around why that would be tho, other than the obvious VPD and respiration effects - which in my mind would effect plant size more than cannabinoid content, and the fact that UV is stronger when it has less atmosphere to pass thru.

And words of wisdom for me?

They are using a greenhouse and supplementing lighting as appropriate from early spring. So i think that is why you get the old plants etc. Kept those babies going for a year or so i guess. Like you said, nice job.

The operative bit, to me, is the measurement of uv they give. Should give you a good idea on exposure with your own ability to measure.

I believe when they are referring to a meristem, they just mean main branch more or less (as opposed to a petiole...not sure what meristem means after topping lol). I.e. main cola.

I have no theory at all for a mechanism with air pressure, but i am suspicious nonetheless purely off of locales that grow good weed.

The hardening off they describe for the uv exposure is of interest for sure. I will have to sit down with different sources to make sure I understand what says what. That would seem to be a very different thing.

 

[Pondracer]

This came in my email today.

Why UV – Mammoth Lighting

What Effect Does UV Light have on Plants? by Vanessa Nielsen, PhD UV light is radiation with wavelengths between 100 nm and 400 nm and it’s not visible to the human eye. UV light makes up about 10% of the total light output of the sun and is divided into several subtypes. The three subtypes...

mammothlighting.com

 

[Kanzeon]

Growing at altitude is one of those lovely concepts that extrapolates really well from wine to cannabis. More solar radiation + aspect + stronger and more frequent winds = stronger plants with more flavor.

What does altitude matter?

What does the term high-altitude wine mean, and what can you expect of wines labelled with this? We explain the advantage of altitude to winemaking and why high-altitude wines cost more.

www.matthewclark.co.uk

How Does Altitude Affect Wine? Ask The Expert!

Get the skinny on high altitude with Anne Bousquet, co-owner of Domaine Bousquet in Argentina in this edition of Ask The Expert at Reverse Wine Snob! Anne tackles the question, "How Does Altitude Affect Wine?"

www.reversewinesnob.com

 

[Moe.Red]

Growing at altitude is one of those lovely concepts that extrapolates really well from wine to cannabis. More solar radiation + aspect + stronger and more frequent winds = stronger plants with more flavor.

What does altitude matter?

What does the term high-altitude wine mean, and what can you expect of wines labelled with this? We explain the advantage of altitude to winemaking and why high-altitude wines cost more.

www.matthewclark.co.uk

How Does Altitude Affect Wine? Ask The Expert!

Get the skinny on high altitude with Anne Bousquet, co-owner of Domaine Bousquet in Argentina in this edition of Ask The Expert at Reverse Wine Snob! Anne tackles the question, "How Does Altitude Affect Wine?"

www.reversewinesnob.com

Would it be fair to say the pressure is irrelevant and as long as we duplicate the light and wind conditions we are optimized

Should I add a windy day simulator to the mix?

 

[Moe.Red]

They are using a greenhouse and supplementing lighting as appropriate from early spring. So i think that is why you get the old plants etc. Kept those babies going for a year or so i guess. Like you said, nice job.

The operative bit, to me, is the measurement of uv they give. Should give you a good idea on exposure with your own ability to measure.

I believe when they are referring to a meristem, they just mean main branch more or less (as opposed to a petiole...not sure what meristem means after topping lol). I.e. main cola.

I have no theory at all for a mechanism with air pressure, but i am suspicious nonetheless purely off of locales that grow good weed.

The hardening off they describe for the uv exposure is of interest for sure. I will have to sit down with different sources to make sure I understand what says what. That would seem to be a very different thing.

I think this test is too different to be compatible. If I ran my lights for the extended seasons and the durations they did I would have nothing but ash where some pretty trees used to be.

I think I am just going to go with the 2 bulbs at 24” starting at 20 mins and working up. Since I will be taking macro shots daily and posting we can steer the test based on what we see.

I will also do a microscopy video of an adjacent bud to the one I am photographing so we can see the trichrome changes against a control.

Add in a TLC at day 1, 5, 10... and we should be able to make daily steering decisions about UV duration.

Of course we will have the PPFD and the UVA and UVB readings so anyone going forward at least has a standard for future testing. I’m gonna guess we learn a lot but also will likely find more things to try based on what we learn. And why not keep going?

Missing anything?