the dark cycle b4 harvest makes the plant think it is dying or something to that nature and tells it to do whatever it takes to survive, i.e. fatten and resin its buds up a lil more,etc...IT cant hurt..I have done it once b4 and liked it...heres a few more shots...the last one isthe Afgan kush ryder that everyone is skeptical about bc it doesnt want to autoflower, but as you can see mine took off at day 19 and hasnt looked back.It looks like its going to be one huge 10 in resinous bud with a few stranglers aside..very impressive so far!