So, I wasn't going to get involved in the thread, as I'd rather spend my time in the room then doing mental work but let's look at the first 4 discrepancies I found between Dennis Brown's comments and Dr. B from Utah State. I'm not saying which is correct cause I don't know, just pointing out the comments which are opposite of each other. There may (and probably will be more) as the thread progresses.
1. Brown says use the entire grow vs. Dr. B says use just last 2-3 weeks for overall plant health.
2. Brown says Indica's handle the UV-B better vs. Dr. B says sativa's handle it much better. Indica's absorb more UV-B because of their larger leaf surface, sativa's skinny leaves are exposed less.
3. Brown says UV-B has little to no impact (3% max) on yield as Dr. B says it can have a larger negative impact over time.
4. Brown says bulbs are the best way for UV-B and Dr. B says UV-B diodes are available (and surely coming) but are very expensive to use so right now it's limited. But prices will fall and then will become more mainstream in fixtures.
Much of what both guys are saying are similar in many ways, but not all. For those who are interested, you can find all of Dr. B.'s videos on Youtube, and I (or others) have posted many of the links in my 3
Gavita threads. I'll again reiterate that Mr. Brown is the owner of a company that sells these bulbs and has motivation to lead you in a certain direction. Dr. B is a professor, who teaches and researches light and it's effects on plants (he has the only U.S. license to use marijuana in his testing facility) for these purposes.
I'm not taking sides either way, I just want to get to the truth. We all want to grow stronger pot, that's the end game. And I hope Dennis doesn't take all this in a negative way, we all appreciate his input and hope to continue the discussion in a meaningful way.