I think it is time for a look back...to look forward with a clearer path - at the beginning of this thread I asked three questions - maybe it is valuable to go back through all of this material and see what has been learned so far (so I went back and read the entire thread all over again.....):
Q1. if UV in ionisers is used for odour control, will high UV light conditions (high altitudes) also influence odour – which has been postulated to have important functionality in the life cycle of cannabis?
there is very little that has come forward on this issue. reference has been made to THCV as the source of the smell. I expect that the smell is from the volatility of these terpenes (cannabinoids), higher terpene levels, greater smell - higher concentration of trichomes, higher terpenes? but it still is not clear to me that - if uv ionisers are used in odour control...how do we reconcile that with the higher trichome count?
Q2. should/could we maybe consider the introduction of a “highly limited” level of exposure to UVB to enhance resin production while within the limited of phytological degradation?
there is a lot of info provided by all posters on this issue, incuding some commitments to do some test procedures. the subjects varied, and included increases in defensive enzyme production, the value in meters and measuring UV light, and cautions regarding the risks of uv light (cancer, eye damage). The more I search and read (and a good bulk of the info is related to the early 90's when concern over the ozone hole had everyone wondering what was going to happen to terrestrial ecosystems from the added UV light), the more evidence (mostly anecdotal and some scientific) there is to confirming some positive value in UV light. I believe we have made some progress in at least understanding the fundamentals of this, but require some speicfic experimental evidence to better to support our theories. I hope we get some good feedback from those have said they will move forward with their own test program.
Q3. do we need to take a closer look at the true comparison of the growth potential/potency of using HPS vs. MH vs. MV lights? Have we been incurring a limitation to potency by using HPS lighting for flowering?
again, we have theoretical evidence that this may be true, but experimental evidence is required to further understand the realities. it seems there is some support for the notion that MH may produce higher quality bud with a compromise on yeild/speed. UV does seem to have some support for better bud quality. It is my belief that the move towards HPS has been driven by the "commercially important " yeild and speed objectives - and maybe unknowingly resulted in some quality consequences. However, this is far from unequivocal. there remain conflicting views. further work is needed. I am inclined to explore the option of combining MH/HPS/UV in some as yet undetermined arrangement. this will not deal with the +/- twelve days of dark (without moonlight) that outdoor plants get....during the typical moon cycle? or does that just make things even more complicated. There has even been some discussion about UV LEDs....however, my information indicates that these do not got to the UVB range and only the UVA range, and if true, will not contribute in a way that we currently understand.