LED and BUD QUALITY

[Charles Dankens]

The only thing ive got against this study is that they are studying uvb, with an incomplete coverage of the standard par range and uva. Between 440 and 290nm there is pretty much zero light. They even mention this themselves, theres a synergistic effect between uva and uvb. You need at least a bit uva in order to build tolerance for uvb.
Beyond 660nm missing far reds leads to an uncompensated blue response which of course leads to less growth and yield.
This paper basicly says that adding uvb leds to standard blurple isnt a good idea, which i feel i more or less agree with.

Im not fully familiar with bugbees uv research but most papers ive seen with "no statistic significant uv effect" usually have at least one hole you can poke in it.
Losing yield: yes, it is to be expected if you add blue/violet/uv without compensating the blue response with higher red/far red.
Total thc in plant dont increase: same as above, if you get higher thc but lower yield of course total thc will remain similar, you need to compensate with reds, especially far red. At least add uv abd red/far red in equal proportions, or you will get non optimal results. Basicly youd need to make test comparing a non uv spectrum to a uv rich spectrum where red blue green proportions are similar. Just adding uv is going to change those proportions towards blue response which means less growth in general. The only light i see on the market that does this prawns boards/strips which use 5 red diodes to compensate near uva diode.

And even so higher thc and quality in exchange for yield may be desirable anyway, depends on your market and own desires.

Ive still not seen any studies trying this except for somewhat non formal testing of @Prawn Connery s boards versus various other lights which have been leaning towards positive results.

Im very happy to admit i may be wrong but i guess im just the kinda guy that has to test all the frigging UVs until i get the results i like, lol

To those basing their opinion in this purely on studies; i suggest you do you our own research aswell (even if it sounds very Q-Anon) and just wire up some diodes over a tray try out how you like the results. We had the best luck with combining uva with high red flowering spectrum; 2700k 90cri + 660nm. Added about 10% of total wattage of uva: no yield reduction and nicer quality; both high and smell/taste.

We also tried 4000k +660nm + uva + far red + uvb which didnt get great improvement of quality or yield.

Waving papers saying "nooooo" at people who actually try for themselves what you dont have the guts to try yourself doesnt seem like a good way of progressing together.

Ya. I hear all that, makes sense to me.
I have 2 uv rigs. I've run various strains under each of them. I have not sent any flower to the lab but I also never felt that I was getting much effect in my setup.

I

 

[Charles Dankens]

"And how many times have you read where someone was having trouble with their "sick" LED plants and put them outside under natural sunlight and – miraculously – their plants recovered"

Under nature. Not just sunlight

 

[Ca++]

What does this add to this discussion other than that you dont believe in UV and you believe this is settled issue? Why do you think its a dead issue when papers keep on coming in which contradict your conclusions? Arent you as much a believer that it doesnt work as the believers are that it works? I mean its pretty clear, there is a paper saying that it does bring THC up, with statistical significance and that UVA raises yield rather than lower it, again what looks statistical significance but id have to check the original paper: how can you state that this is settled? The only way to get to your position is by
1: having already decided what you think (and that without having tried uva afaik). I know you made some tests with uvb tubes and hps way back but i dont think its the same really. Both are hot lights and tend to evaporate terps and cannabinoids.

2: not being able to read the paper. Cause dude, its pretty black and white. And when science are going in two separate ways then its not settled or dead.

3: Valuing other papers higher than this one. If this is your point, that you think that other papers already settled this then you need to argue your point why the science you prefer is better than whats under discussion here. Bring some decent papers and quote, however the stuff ive seen you bring has been kinda middling science and conclusions; this is why we ask you for more than just saying "this is settled long time ago" and some stuff about getting banned for proposing under cannopy light; thats bot even an argument.


Im sorry if I sound shitty and confrontational, you know i appreciate you to the extent that i do believe youre trying to help people generally, but when you try to close down a discussion about science and opposing papers by using arguments from authority without any actual factual argument or quoting nothing relevant then i will call you out a bit. If you want to argue from authority you need to actually show youre an authority, and even then you need to still be able to engage with the actual points of the discussion, not just say this is closed cause i say so. Im sorry but i will continue calling out this kind of expression.

Does the paper I quoted contradict me though, or are you displaying wishful thinking.
Can you show me where THC yield increases.

It's been posted countless times by both parties. How can we both use the same evidence to prove a different point. I believe one party is wantonly seeing things that don't exist. A confirmation bias, that is carried from paper to paper.

 

[Prawn Connery]

 

[Prawn Connery]

The idea nobody has tried uvc for instance, is untrue. The idea that's from a paper and not trying it, is untrue.

Belief defies logic. If people need it to be true, they will not see evidence it's not.

You mean, like the evidence that I said any of this? ^

Or any of this?

I'm not rewriting physics, but look at your special values. You are just inventing some units, miscalculating others, and others are just downright backwards. That's quite a collection.

Are you a careless reader? Or are we seeing a pattern of behaviour here?

 

[Rocket Soul]

Ya. I hear all that, makes sense to me.
I have 2 uv rigs. I've run various strains under each of them. I have not sent any flower to the lab but I also never felt that I was getting much effect in my setup.

I

What uv are you adding to what spectrum?

We did 4000k+660+730+uva and uvb. Tray looked awesome the whole grow but the smoke was normal-ish nothing special. My guess is that too much green will inhibit the uv response.
We had nice results with about 10% of watts addrd as UV to a very red leaning spectrum.

 

[Rocket Soul]

Does the paper I quoted contradict me though, or are you displaying wishful thinking.
Can you show me where THC yield increases.

It's been posted countless times by both parties. How can we both use the same evidence to prove a different point. I believe one party is wantonly seeing things that don't exist. A confirmation bias, that is carried from paper to paper.

The way i read this is not some kinda slam dunk either way; it says that if there is a trend in either way its hard to nail down in a scientific experiment, theres too much variance in the values. See those P values? What do they mean to you with regards to statistic significance? The only thing close to statistic significance is in cbd yield and even so it misses statistic significance by +100% (p: 0.11 vrs P:0.05)

Im not so much trying to prove you wrong re thc yields as i am saying that this is not a settled issue; we get results indicating in both ways. Enough for me to try this out.

Im firmly in the belief thats its probably easier to get an effect in a grow off where youre just try your best to grow every plant to its fullest rather than trying to keep every variable constant. Pulling of a successful experiment and a successful grow is not the same.

With science being what it is im firmly for more info and testing and i do welcome a bit of pushback, but i cant really accept that this is a settled issue as you say based on whats being brought to light by different research. If theres nothing in it for me then ill happily drop it. But if it moves the bottom line due to higher crop quality commanding a higher price then thats good enough for me.

 

[Rocket Soul]

View attachment 18944680

The more i look at this the more confused i am; is this another one of those low thc studies again? Thc hovering under 1%

Edit: Why are we even looking at numbers without statistic significance of the wrong plant?

Also, but this may just be that my numbers are off, but does the uv dose look a bit low?
Im getting around 2 dli of uv when working on a basis of 5% uv of 1000 ppfd. Those graphs go as far as 0.12.

Is this actually a study about what happens to a CBD plant when we increase uv from 0% to about 0.3%?

 

[Prawn Connery]

The more i look at this the more confused i am; is this another one of those low thc studies again? Thc hovering under 1%

Edit: Why are we even looking at numbers without statistic significance of the wrong plant?

Also, but this may just be that my numbers are off, but does the uv dose look a bit low?
Im getting around 2 dli of uv when working on a basis of 5% uv of 1000 ppfd. Those graphs go as far as 0.12.

Is this actually a study about what happens to a CBD plant when we increase uv from 0% to about 0.3%?

That was the from the Bugbee study (not the Llewellyn study) and so yes, they used high CBD strains because they can't grow high THC strains in Utah for legal reasons.

 

[Rocket Soul]

That was the from the Bugbee study (not the Llewellyn study) and so yes, they used high CBD strains because they can't grow high THC strains in Utah for legal reasons.

Lordy. In this issue everybody is quoting a guy doing studies about another type of plant and using a scale of less than a 10th of the uv range present in sun light?

I dunno but i get a weird feeling ive been losing too much time on this. This feels a bit pointless.

 

[Prawn Connery]

Lordy. In this issue everybody is quoting a guy doing studies about another type of plant and using a scale of less than a 10th of the uv range present in sun light?

I dunno but i get a weird feeling ive been losing too much time on this. This feels a bit pointless.

Long post, but hopefully this clears things up: https://www.icmag.com/threads/led-and-bud-quality.18123147/page-127#post-18513372

There are two main studies that are usually cited by those who claim there is no evidence of UV (UVB or UVA) influence on cannabinoid synthesis. ^ These are those two studies.

Most UVA skeptics usually leave out the 2018 Magagnini study that found otherwise. Here is that study that also looks at blue, violet and UVA ~400nm.

The Effect of Light Spectrum on the Morphology and Cannabinoid Content of Cannabis sativa L.

Abstract. Cannabis sativa L. flowers are the main source of Δ-9-tetrahydrocannabinol (THC) used in medicine. One of the most important growth factors in cannabis cultivation is light; light quality, light intensity, and photoperiod play a big role in a successful growth protocol. The aim of the...

karger.com

 

[Rocket Soul]

Long post, but hopefully this clears things up: https://www.icmag.com/threads/led-and-bud-quality.18123147/page-127#post-18513372

There are two main studies that are usually cited by those who claim there is no evidence of UV (UVB or UVA) influence on cannabinoid synthesis. ^ These are those two studies.

Most UVA skeptics usually leave out the 2018 Magagnini study that found otherwise. Here is that study that also looks at blue, violet and UVA ~400nm.

The Effect of Light Spectrum on the Morphology and Cannabinoid Content of Cannabis sativa L.

Abstract. Cannabis sativa L. flowers are the main source of Δ-9-tetrahydrocannabinol (THC) used in medicine. One of the most important growth factors in cannabis cultivation is light; light quality, light intensity, and photoperiod play a big role in a successful growth protocol. The aim of the...

karger.com

My take away from the magagnini paper seems to be that the ns1 phosphor blurple seems to have done really well; it trends higher thc in % and cannabinoid yield per plant... Maybe we should be looking at low green aswell.

 

[phunkeeboodah]

it is proven though that thc production in high thc varieties and cbd production in high cbd varieties are inversely triggered with photoperiod manipulation during flowering

where 14L/10D for flowering will more than double weight and cbd production in high cbd varieties, and result in a 2/5 loss in weight and thc production in high thc varieties

silver lining though high thc varieties can sometimes yield double the weight and thc with 14L/10D if it is for only half of the flowering period and the other half (doesn't matter wich one) is 12/12

 

[Rocket Soul]

it is proven though that thc production in high thc varieties and cbd production in high cbd varieties are inversely triggered with photoperiod manipulation during flowering

where 14L/10D for flowering will more than double weight and cbd production in high cbd varieties, and result in a 2/5 loss in weight and thc production in high thc varieties

silver lining though high thc varieties can sometimes yield double the weight and thc with 14L/10D if it is for only half of the flowering period and the other half (doesn't matter wich one) is 12/12

This is real interesting, is there any link pr reference of the study?

 

[phunkeeboodah]

This is real interesting, is there any link pr reference of the study?

the study is from australia, and the video linked from usa does a similar study with similar results but focused more on bud ripeness and quality

Moving Away from 12:12; the Effect of Different Photoperiods on Biomass Yield and Cannabinoids in Medicinal Cannabis

The standard practice to initiate flowering in medicinal cannabis involves reducing the photoperiod from a long-day period to an equal duration cycle of 12 h light (12L)/12 h dark (12D). This method reflects the short-day flowering dependence of many cannabis varieties but may not be optimal for...

www.mdpi.com

 

[Prawn Connery]

So the high-CBD strain did the opposite of the high-THC strains. So much for Bugbee's "hemp" trials, lol! Just goes to show you don't know what the plant will do until you do it.

 

[Crooked8]

So the high-CBD strain did the opposite of the high-THC strains. So much for Bugbee's "hemp" trials, lol! Just goes to show you don't know what the plant will do until you do it.

View attachment 18945204

Unfortunately we dont have nasa and federal funding to study the subject the way bugbee does. We cant take live photosynthetic rate analysis without a machine that costs 60-100k. We cant do our own tissue testing. We dont have chambers to test different strains side by side at precise cardinal parameters. Let’s not discount his findings, he's one of the most accomplished agricultural scientists alive in my opinion. So far, using his methods has made our yields and quality improve dramatically. Not to mention that they do have contacts with people studying drug type cannabis and relate their results to theirs. Often times, there are corresponding increases and decreases in yield and cannabinoid content.

 

[Prawn Connery]

Unfortunately we dont have nasa and federal funding to study the subject the way bugbee does. We cant take live photosynthetic rate analysis without a machine that costs 60-100k. We cant do our own tissue testing. We dont have chambers to test different strains side by side at precise cardinal parameters. Let’s not discount his findings, he's one of the most accomplished agricultural scientists alive in my opinion. So far, using his methods has made our yields and quality improve dramatically. Not to mention that they do have contacts with people studying drug type cannabis and relate their results to theirs. Often times, there are corresponding increases and decreases in yield and cannabinoid content.

Ever heard the expression "All the gear and no idea?"

I'm not saying Bugbee has no idea. And I am not casting aspersions on his scientific knowledge or achievements. He has done contract research into space farming for NASA . . . Although it was NASA who gave us the "Blurple" LED, remember?

However, for the longest time now I have been saying that his experiments on industrial hemp and CBD strains is not the same as testing high THC cannabis.

Now we have a scientific study that shows why. Three plants all subjected to the same treatment and the high CBD plant did the opposite of the high THC plants.

Yet people will still use Bugbee's findings as incontrovertible proof that UVA, violet and blue do not have any effect on THC synthesis.

Bugbee's studies have their place. And Bugbee's lectures and videos are great for those who are learning about horticulture and indoor lighting as he provides the basics in a very clear and easy-to-understand manner.

But on the more advanced topics, those who already have a lot of experience with indoor lighting – and especially growing high THC cannabis – are starting to find holes in his findings and theories.

Let us not forget, either, that he is a salesman. He represents Apogee PAR meters. When Apogee brought out an ePAR meter that measured Far Red, Bugbee was all over those Far Red studies, touting the importance of it. Apogee doesn't make a PAR meter that goes fully into the UV range.

 

[Crooked8]

Ever heard the expression "All the gear and no idea?"

I'm not saying Bugbee has no idea. And I am not casting aspersions on his scientific knowledge or achievements. He has done contract research into space farming for NASA . . . Although it was NASA who gave us the "Blurple" LED, remember?

However, for the longest time now I have been saying that his experiments on industrial hemp and CBD strains is not the same as testing high THC cannabis.

Now we have a scientific study that shows why. Three plants all subjected to the same treatment and the high CBD plant did the opposite of the high THC plants.

Yet people will still use Bugbee's findings as incontrovertible proof that UVA, violet and blue do not have any effect on THC synthesis.

Bugbee's studies have their place. And Bugbee's lectures and videos are great for those who are learning about horticulture and indoor lighting as he provides the basics in a very clear and easy-to-understand manner.

But on the more advanced topics, those who already have a lot of experience with indoor lighting – and especially growing high THC cannabis – are starting to find holes in his findings and theories.

Let us not forget, either, that he is a salesman. He represents Apogee PAR meters. When Apogee brought out an ePAR meter that measured Far Red, Bugbee was all over those Far Red studies, touting the importance of it. Apogee doesn't make a PAR meter that goes fully into the UV range.

Why bring up that expression and then reference nasas blurple light if you arent indicating hes unaware? I understand the inconsistencies you may have found with some of his studies regarding high thc cannbis. Id like more details on those if you have them besides this 3 plant study(who did that study and where is that info from?). Id also love to see that same experiment with more than one cbd plant, weve certainly seen how different strains of drug type cannabis behave very differently. Ive been growing high thc cannabis for over 20 years. I still have had many ah ha moments and realizations through his very detailed courses with royal heins and mitch wesmoreland. His light meter was an extremely helpful tool so im glad i bought what hes selling there. They do have a meter for UV-A https://www.apogeeinstruments.com/uv/

And im just curious, are you also a salesman? Iirc correctly you do sell Led lighting, do they happen to feature UV diodes?

 

[growsjoe1]

And im just curious, are you also a salesman? Iirc correctly you do sell Led lighting, does they happen to feature UV diodes?

???