I’ve got 30 healthy female marijuana plants that range from 14 to 30 inches. We are just starting to flower, and I was wondering if there would be a major difference in yield if I started the first two weeks at 12/12 and then dropped it down to 10/14 to speed up ripening. People have told me that there isn’t much of a difference in the end. I want the best marijuana yield possible.
The amount of light directly correlates to the growth of the marijuana plant. Less light means less growth, and, in your case, you’d lose about 16% of that potential growth. A shorter light cycle means that the marijuana plant is producing less tissue and will not grow as much.
The marijuana plants will, however, ripen faster with a shorter light cycle. The total growth period is reduced when you reduce the amount of light during the “growth section” of flowering. In general, though, this isn’t a good trade-off. You’re reducing both the total time under light and the percentage of time with the light. Thus, you’ll be losing more yield than you might expect with the low-light cycle.
The final 10 days of flowering produce little growth. The marijuana plants transform as the stigmas dry. The ovary begins to swell and THC fills the glands. If you reduce the light cycle in this case, you can speed up ripening without reducing yield.
Certain factors might make faster ripening periods more desirable that maximum production. In those cases, a 10/14 regimen would suffice.