Peejay, how and what do you look for in maturities in the plants. What is the key thing to look for. Or is it just 4 to 5 weeks.
7, have you seen how folks look at photo-period plants and can tell the sex even before the flip? Usually they are looking for those little white pistil hairs. When a plant starts "showing sex" = sexual maturity - sort of like humans an puberty. A photo period plant can keep growing and won't flower after it reaches sexual maturity if the light schedule stays long. The auto doesn't care about the light schedule. It starts to flower as soon as it is old enough to flower.
There is a bunch of stuff out there - lots of pictures of plants showing sex before the flip. I know Canna has some nice ones - she takes amazing macro pictures.