Science of light

[JohnEmad]

Thanks YYC, appreciate the tip.

[Toker1]

I’d be willing to bet dollars to doughnuts that UV exposure resistance is strain dependent. Mountain strains (kush) should fair better than strains closer to sea level (Durban Poison). Just a theory.
The higher up in altitude you go, the more UV exposure you endure.
Personally I run mine 15 min on and 2 hours off during lights on. But that schedule was due to the manufacturers recommendations.
I once f’d that schedule up (by leaving the lights on 24/7) and saw noticeable damage on my leaves. After I fixed that, the plant recovered just fine.

[YYCannabis]

That comes back to my point on how there is not enough info.
What’s ideal length of exposure? Is 10 minutes per hour the number, or will 10 minutes per hour cause plant degeneration? These are the things that need to be studied. I see someday soon that it will discovered what is the golden ratio for UV and it will be amazing.

[Toker1]

YYCannabis yes, there is an aspect of that for sure. Where I live in Cai low quality wont sell (black market and commercial alike). High THC is the target market.
With that being said, we also must discuss the dynamics of UV and final yield. Because UV light is quite damaging to plants, when you supplement UV your final yields diminish slightly. So if your target market wants quantity over quality, then adding extra UV light might not be in your best interest.

[YYCannabis]

JohnEmad Use the far red once the plant has stopped growing in size and is in dedicated bud growth. This should help the calyxes fatten up and grow slightly longer buds. Just keep an eye on canopy surface temps as the far red will cause a small rise. 😉

[YYCannabis]

I’m not saying UV isn’t proven to help in THC production. My view is that there isn’t enough return on investment for adding UV (cost of lights and operating them) without knowing the correct method of applying UV (intensity/duration). If the gain in THC is only going to be a few percentage points, I don’t need to worry about it since what I’ve managed to grow on my own is already top-shelf quality.
Now, if somebody has a goal to grow the highest level THC that is biologically possible, then go for it. Or maybe they grow from a commercial aspect and customers will pay more $$ to have for example, a 30% vs a 28% herb.
I do admit that having the benefits of being a fungicide as a side effect does make it slightly more appealing for people in damp areas that need to combat WPM.

[Toker1]

Great video. Completely agreed, it’s not the data that drives misunderstanding. It’s our interpretation of that data that causes it.
Thanks for sharing!!

[JohnEmad]

still research going on into percentages of far red and UVB and when to use it. I believe my QB with a far red strip caused my autos to really stretch. I may keep the FR strip unpluged this grow to see if they stay shorter.

[Toker1]

UV light and THC production experiments from the 1980’s did conclusively prove the beneficial relationship.

[YYCannabis]

Right!?! But need to keep in mind the other 8 key factors and keep them in balance with level of light.

[YYCannabis]

I think he had commented in some of his other vids about UV. It’s still a big part of their research. I decided to hold off on adding UV to my lights because there is currently no reliable information as to how strong or how much UV the plant can tolerate/need.
And since watching this vid, I’ve decided to not add extra lights for an Emerson effect setup.

[BR2K]

It also stuck out that he quickly shot down the Emerson effect as not being necessary.

While he didn't absolutely confirm that UV was important to cannabinoid production, it seems very promising.

[YYCannabis]

It also stuck out that he quickly shot down the Emerson effect as not being necessary.

[BR2K]

Wow!!! I'm especially surprised about the amount of light seedlings and cuttings can endure. Thanks for sharing!

[Obi-Wan]

Great video!!!! Thanks for sharing it, I like that he explains that while Cannabis can take more light, it’s important to make sure all other factors are being monitored.