I've only just started growing Autos and i'm having some weird stunting shit going on. I've been doing lots of weird shit like repotting them and topping, one i scared into flower after 4 weeks, she's 8" tall and i think she's quit.
I had a brain wave just today and checked out my pH. I think i'm nute locked as my pH is 7.4 so girls not happy. Emergency pH down (citric) ordered as i think i need to flush them through with pH corrected water before they finally sort their shit out. Autos are like race cars man, if you've not got your environment dialled in from day 1 you're fucked (in terms of yield). You'll get some bud of decent quality but yield will be way off. Like when you read 660g per m2 on a packet, i mean i'll be happy getting 6.6g per m2 from a couple of my stunted blueberry autos.
I'll report back on the pH change if it recovers them like i think it will. If your soil is not 6.6 pH or lower with Autos they aren't gonna fly like a photoperiod would with the same light. Peace, love and bud. HN.