i top all my autos, mainly for stealth reasons by keeping them shorter. the yield is not diminished because of smaller but many more colas. i started a thread on this a few days ago. check it out. GL
https://www.autoflower.org/f2/topping-autos-19775.html#post381062
https://www.autoflower.org/f2/topping-autos-19775.html#post381062
. Great growing my friend

