I also thought it was for catching pollen. They say sensimila has more resin content cause the female produces more to try to catch more pollen.
Orange SHovel. Your MH do produce a slight amount of UVA, UVB rays. If you where to add a UV lamp, have both HPS,MH when flowering you will see a considerable amount of more resin then with out it.
TMB, 100 feet might not sound like a lot. I'm in FL 6 feet above sea level. That extra 100 feet, believ me makes a dif., the sun is so intense here.
Back to it being sunblock. I'll quote what he said. "THC is the cannabis plant's sunblock. So the more ultraviolet rays the plant receives, the more punch it will pack. Where would you expect to get a worse sunburn, on top of a tree or under grow lamps? I have conducted extensive experiments in hash and hash oil refining and have found that the THC oil content in my plants is 15% higher than hydroponically grow cannabis commonly sold on the streets."
In that chapter he, is comparing his methods of growing compared to hydro in doors.
Mr.X God Bless