We did a lot of experiments with light times a few years back using known sat and sat dom clone lines.
With Vegging ie under hid lights.
20/4 produced the most sturdy growth and the most bulk. Best final yield, taken as 100%.
22/2 Less of both. yield 88%
18/6 Studier than 22/2 but slightly less bulk. yield 87%
24/0 Much lighter in all aspects than 18/6. Yield 79%
16/8 The weediest plants. yield 67%
Plants vegged to final pots under fluorescents at 20w per sq ft on 18/6 yield 49%
Have not tried 36 hrs dark but did try 48 hrs from 18/6 veg. The final yield was down between 15 and 20% by var the pure sats the biggest loss in final weight and caused the odd herm, [sats] it did reduce the flowering time by 5 to 8 days.
For the mum lines we have 20/4 to 12/12 gives the best crop weight and bud quality, really thats all I’m interested in.
