No....it's a photo-period. This is my first sativa grow (been doing indica for awhile) and it's all new to me as far as how they grow out. I had another plant of the same strain that never budded, and the branches were all limp and chopped it. I have another that's growing fine, and this one that I'm talking about today is the "Trying Uncle Bens" thread in my signature.
None of these three have grown anywhere like each other. I've found that I'm an indica grower for a reason as I like the faster flower time and how well the plants grow under my conditions.