To add, if anyone here wants to experience tannins, drink a young Barolo from Piedmont in italy. That wine will suck the life out of your mouth. Pair it with some ribeye and its heaven. Or, simply eating a persimmon can really teach you about tannins for a non alcoholic experience hah.
I cant speak to OPs post but if youre wondering about the Bugbee research team its pretty darn current. They did experiment with the wavelengths in combination i believe as well. I wish i had it in front of me. Drives me nuts that they take the damn modules away after the exam.
How many experments did he do and on how many plants both with and without...Its ashame the full pages and pages of results over his numerous grows over a few years on uv alone arnt available.
re intensity: are you sure it was uW and not mW? Most uvb diodes have output in this range. 130 uW would be almost a factor of 1000 less than what were giving our plants.
From a post of his on another site: “The reading is 122 uw at 29", enough to make a large difference as it is on the full 12 hours, not just…”
Frosty plants look nice yield more resine for extractions and tipicaly will bhrn slower and nicer in a joint so i dont get why you would you bitch those who like frosty plants
First you got the uvs back to front: theres nothing between uva and blue; they are nieghbours, uvb is deeper beyond blue and uva and then uvc, which is germicidal and will rightly f-k plants up.As light shifts from red, to blue, and beyond, it carries more and more energy. If we think about photons as particles, it's a little easier to grasp. Red photons carry a little energy, that the plant can easily dissipate and use. Blue one's carry twice as much. Some plants thrive on these blue photons, and find red ones a bit like light snacking. While other plants are great at harvesting red ones, but find blues one's a bit hard to swallow in one go.
Skipping ahead to UV-A, we have photons with so much charge, it's like trying to survive a lightening strike. UV-A is germicidal. It's outright death to many organisms. The gap between UV-A and blue light, is filled by UV-B and UV-C. The big picture I'm trying to paint, is how UV-B is close to death. I'm not aware of any plant that want's it. Nor UV-A. The bigger picture is that blue isn't great for our plants either. The UV story should be old news by now, and I don't even see it as worth talking about. We are now establishing that blue isn't favourable to cannabis. This isn't at all uncommon for plants in general.
If we use blue, we see protection methods at play, that are usually spoke of in these UV talks. Less stretch. Smaller leaves. Thicker surface layers to the leaf, to reduce light penetration. It's not quite triggering the carotenoids to make colour filters, but we know they are having to work hard to stop chlorophyll destruction, by these high energy particles. Which are not high enough for us to call them UV, but are actually visible to us, as blue.
That holistic picture should go a long way towards explaining why UV-B offered nothing but stunting, as the plant spent energy on repairs and protection. Growing ineffective leaves, and keeping away from the light. These are not the qualities of a good light source.
Lots of tests looked at a whole bunch of cannabinoids. Just as now, many people were willing it to work. You can even find papers where levels increased, as what there was, had less bud real-estate to occupy. Giving more useful cannabinoids per gram of flower, but unfortunately, very little flower, so the plants overall yield of these chemicals was lower. But.. per gram of bud... more. So people can hear what they want to from that.
There is little to gain from UV, but plenty to loose. It's probably good that the UV LEDs in our lights are ineffective. Placed there, just because people asked for them. Right now, we are reducing the blue in cannabis lighting. Getting it down towards sodium levels.
On a slight tangent, the HID vs LED debate often finds HID supporters, even after side by sides. Their LED is generally unknown to us. It's quite possible that higher blue is the driving difference. Most accept a wider taste pallet comes from LED, and nobody quite knows why. Yes, more colours, more tastes. However, we can't ignore it's not gaining tastes they speak of, but loosing tastes. So we look to loosing IR. However, nothing says the loss in some tastes, isn't due to gain, or change in processes, due to the blue gain.
OK, I obviously want to talk blue as I feel UV is a dead topic.
Back to topic though...
Prime your weapons, and take your shots
some of natural substances linked with protection from uv like limonene also aid's indirectly to help increase the plant's ability to Photosynthesize light by reducing its stress response from uv allowing it to spend more energy for absorbing light, this could be potentially linked with the observation, while some compounds such as anthocyanins compete with chlorophyll in certain areas of the light spectrum and actually inhibit photosynthesis, to an extent. in basic terms the uv resistance allows the plants to absorb more light without getting burnt, makes the leaves more efficient in photosynthesis. adding uv will increase leaf durability in regards to light/uv intensity allowing the plants leaves to absorb more light theoretically.
I didn't,the implication was people associate frosty plants with higher quality resinFrosty plants look nice yield more resine for extractions and tipicaly will bhrn slower and nicer in a joint so i dont get why you would you bitch those who like frosty plants
Oh yes, quite the brain fart there, getting the labels the wrong way around. Labeling aside, the picture is whats important.
through to, and including, blue. I'm not sure where green falls. It's in the zone where the light radiation becomes good. Yet our plants are not making a grab for it. They are more attuned to collecting blue. 
Oh yes, quite the brain fart there, getting the labels the wrong way around. Labeling aside, the picture is whats important.
It's worth recapping here, that the amount of energy a photon carries, gives it different amounts of physical interaction with what it falls upon. It's these different levels, that we interpret as different colours.
I'm not sure what a better looking leaf is to anybodies eye. The leaf protecting itself is greener and thicker, not paper thin and letting light pass through so easily. Many people value those thick shiny leaves, that are trying to block light. These protection mechanisms would lead to higher intensities being possible, as that goes hand in hand with being better at blocking it out. As you say, their can be room for interpretation when few facts can be checked. Thus..
I have done my own trials, yes. Just three times, and it was not effective. I'm not going to use that as evidence though. You are right, that I would rather get out the papers of people like Bugbee's team if I'm to offer proof. Which I feel has more value than someone's personal findings. Usually offering a lot more detail, than I can produce with my casual interest.
I wrote off UV quite a few years ago now, and can say with some certainly, that no papers will be posted here to say I was wrong to do so. Yes, a few growers still wish it were true, and think theirs is the best, no matter what they do. These outliers will always exist. However the use of UV in basil production is of little interest to a cannabis grower, and turning to coral to find a plant that uses it, really does show how few plants want it.
The picture I'm trying to paint, of higher energy photons being damaging, has held true for me, through years of study. It explained to me how blue was bad, which I shared here as my thoughts, before the studies started to back it up. It's a logical picture, that needs no further thought in my mind.
Papers aside, I will talk personal opinion for a moment.
If you have a Mole of light in blue, and one in red, the red one contains twice as many photon units. Our plant does exceedingly well at processing large amounts of these small charges. It's a specialist. However you can't have everything. This excellent use of late season light, has a cost. It's not great with energy packets twice the size. It shows us quite clearly in it's actions, and now testing supports my model From UV-C
Up to 30% blue, little unwanted behaviour is seen. After which, things rapidly change, with 40% blue being an utterly pointless harvest. The blue chlorophyll response peak, is flanked closely by the two peaks in carotenoid response. Who's job is protecting the process from over-run problems. They have a few mechanisms to do this. Making blue light handling possible, but only to a certain level. After which the protection methods employed, are getting a bit like shading. Purple being a common colour seen. Usually outdoors, where a broad spectrum is seen. Not the peaks of most electric lighting. Which is a different pet topic of mine, regarding how we target the blue production peak, but not protection ones.
I have no doubt that UV offers nearly all growers a loss. Even if it was just a loss of 5 mins, reading my concentration taxing post
My three tries? Two were in rooms that ran like clockwork, and they looked a bit more leafy. By that, I mean more layers of leaf in the buds nearer the lamps, which were a little greener looking. All quite short, like they tried to grow out, but didn't want to. Leading to attempts elsewhere. This increased trimming time, and did nothing for the end product.
What base spectrum did you add uv to?
