Quote Originally Posted by doco
Also, some of the lowest branches are never going to amount to anything in the end so I prune about 3 sets of them off about a week before flowering and allow the plant to concentrate it's energy into the bud sites that can better use it. Leaving them is no big deal, just more larf for the hash makings.
Removing the lower branching in concert with flowering cuttings as soon as they have good roots is the Sea of Green type technique. The lowers block air circ and produce fluff like doco said- I also find it expedient to just not grow that part of the plant.