The article you posted above also discussed the shortening of day length during the flower cycle. I found their reasoning to be interesting; that they'd found evidence that the plants had soaked up all they could use of the light in just six hours, and the rest of the day was a waste.
I wonder if this is a timing thing or if irradiance is also a factor; then it occurred to me that I've been coming at the same energy savings from the opposite direction; my grows run between 25-30W/ft², barely half the industry standard, yet I'm getting good results.
What if one increased irradiance, but reduced day length? The DRI, daily light interval of duration x irradiance would still seem to balance in this case.
Finally, back to the all-important yield. If reducing day length significantly hurts weight, it isn't progress. Even if a seventh crop (6 crops x 8 weeks = 48 weeks) could be squeezed in, if the end result isn't more yield then again, not progress... just an extra crop's worth of work!
Yield quality must also be carefully assessed, especially considering that we aren't really interested in the leaves, stems or even the buds themselves... but rather the resin the plant creates and secretes on its surfaces.
Personally, I suspect shorter days with stronger lighting might actually be beneficial for trichome production... Again, this would need to be tested.
