Have you ever listened to Heavy T's grow show? DFZradio.com Anyways, they are a radio show and I have heard them say that defoliation has personally worked for them to increase yields. I'd like to say 2 things about that statement. 1st. Not massive defoliation, 30% of the fan leaves at max is what they have said, an 2nd If it increases the amount of light that gets to the lower bud sites and the plant pulls its energy from the roots then I think it can increase yield. Who knows tho, I've been practicing it somewhat, when I'm not lazy or doing other things.