Less lighting after flowering?

[Mcdoolit]

Okay, so I have 3 plants from bag seeds. One ended up being an auto and has started flowering. I have about 3 or 4 more weeks of 19/5 lighting for the other 2 plants to get longer in veg state...then, I was hoping to switch to 12/12 to induce flowering for my other 2.
Will that less lighting mess up my auto?

 

[TorturedSoul]

Mess it up? No. You'll only have 12 hours per day to give it light, though, so just do what most people who grow photoperiodic strains do when they switch to a flowering schedule (e.g. switch from a 400-watt HPS to a 600-watt one, or whatever) - increase the lighting by about 50% and rock on, lol.