Thanks for running and posting your experiments PF !! I found this several years ago . 

During the nighttime hours, our ladies are busy storing food down in their root system that they made during the daylight hours. During “lights out,” starches and sugars produced by photosynthesis during the day drain downward to the roots. Knowing this, it is easy to figure out that you want to cut your plants away from the roots before the lights come on, when food moves back upward into the buds.

Outdoor herb is often harvested during the daytime hours and the result is a harsh, difficult burn and an extra long cure. The starches and sugars present in daytime-harvested herb act like fire retardants—not the effect we’re looking for. In addition to tasting and burning bad, these fire retardants also change the chemical make up of the smoke you’re ingesting. This means that the THC, cannabinol, and other active cannabinoids can’t burn at the perfect temperature to get you properly high because they haven’t properly converted to their psychoactive forms.