Jeezus ….
There is
no stable method to delay an autoflower unless you purposely stress it. You more than likely stunt the god damn thing and then what ?
You can overfeed it , overwater it , kick it or whatever to gain what ?
I’ve had autos pull a fast flower at day 22 from germ …. So much for a decent
veg .
They are unpredictable…. Both good and bad. That alone can affect what you get in end.
Shitty genetics , First gen offerings ( no further line work ) and unpredictability.
Just give them the best you can
UPFRONT to ensure the best you can squeeze out of it. Grow skills play big into this.
Outdoor autos can get pretty big ( supers and xxl ) , indoors - DWC / HEMPY .
Sure there are some “ tricks “ to help :
Run 24/0 upfront for the best chance of rootmass then at preflower drop to 18/6 or 20/4 til end.
Add silica / kelp to all grow medium … is another trick.
Light aerated mixes allow for fast rooting ….. simple 1 or 2 part feeds also.
Stagger auto starts for perpetuals.
Autos can be topped , fimmed , super cropped .…… hell I chopped one in half ( still grew )
They are wired to run on their own terms .
If you prefer long veg … run photos . Run SOG clones or even 12/12 seed drops.