Awsome thread guys, and some nice plants. I did a little experiment of myself before harvesting the top colas of my Afghanis.
I stuck the three in a closet to control dark period. 2 of them got 15 hours of dark(I slept in), and the other 36 hours. Then I took the top colas and put them back in the room to finish up the bottoms, tomorrow I'll take the bottoms using the same dark period for each plant.
So far we noticed that the plant left in the dark smokes a little nicer and is a little more potent, but she was the better plant to begin with, so hopefully the bottom harvest is a little more equals seeing as how they were all shaded.