my only problem is it really depends on the strain, ive had autos grown under 20-4 and 24-0 that start flowering at week 2 around 4 inches high, so they just continue to flower after that, so very little can be done with them.
but like the kc45 autos im working with, everyone says autos must be grown under 24-0 and 20-4 else yield will be affected, well ive grown several kc45 autos under 20-4 and 24-0 and i was lucky if i got a 1/4oz dry per plant, pushing 3 x 8ths at the most, so i then decided to try autos under 12-12, my grow room was on 12-12 so why not, i thought id end up with tiny plants, but the plant didnt start flowering till 2 weeks later than under other schedules, it was well over 1ft when it actually started flowering where as on the other schedules it finished at less than 1ft, at harvest i got just over 2oz dry, i got other k45 autos growing now, again under 12-12.
all are over 1ft, one is male so collecting pollen in another location, the 2 females are only just starting to flower and both are just over 1ft at start of flower,
so it seems the kc45 auto preffers 12-12, i just grew a purple cheese auto under 17-7 and it performed very poor, no side branches as such just buds sticking out, i got around 17g dry, so that did poor under 17-7, ill try more strains and see what works best, but the kc45s done a whole lot better under 12-12 which contradicts all the theroies on how to grow autos, i do use basic lst with the autos, i might pull some big fan leaves out the way but not remove them from the plant, i some times sort of bend the plant over to let light into nodes not getting much light, that seems to work ok