from my past experience i noticed the mass of roots will mostly not go deeper then 4-5 inch [70% of root mass] but i hear with autoflowers wen ever the main root hits the botom of the pot if wen it will actually go from Veg state to Bloom state ,im doing a experimental grow with a 5 inch deep random ice cream jar that i puntched holes in the botom ,il probly post my grow in a log here later this week end the seedling gets a litle more picture worthy :smokebuds:
if this were the case why would ones in nature auto??
i have had many flower after one internode after selected breeding for them to do so and they were far from the bottom of the containers
it is a genetic trait passed on
some auto at earlier times than others and dif internode lengths it depends on the previous genetics choosen from to determine when it will flower