Well this a a tricky one. Based on my experience and talking with some other comercial auto breeders, the auto flowering process is intiated when there is stress to the roots. Meaning the tap root reaches the bottom of the pot, or the roots start to ball around the pot.
Thats why stunted plants are usually so small, if you pull them out youll see a root ball usually no bigger than your fist. The roots experienced so much stress that it caused to plant to flower immediately.
Hydro growing methods challenge this theory a bit, like in your small coco pot grows.
From my experince in 2gal organic soil pots autos will flower in 2-3 weeks and should finish in the 70 day range. I run this style of growing for a quick harvest or to test out some new strains.
I also run large 15 gallon pots with living soil. Plants in this setup often dont flower for 3-5 weeks and wont finish for 100 days plus. (Well beyond the 4th node) But they will often be 4-6 ft tall, 3 ft wide and easily yeild 6-12 oz.
So i guess my answer is that we dont really know for sure, and we are still trying to find some eaxct science on this. And the answer for soil and hydro methods could be very different.
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