Dan K. Liberty said:
I will throw something in on this . . . I think that it's possible that plants are more inclined to show preflowers in veg . . . not only based on strain and sexual maturity (hitting the "teenage stage") . . . but also on the uninterrupted progression of nodes on the main stem.
I say this because I've noticed that, with any given strain, individual phenos seem inclined to show preflowers at the same location . . . typically, it's between nodes 6 and 8 on the main stem. Strains that are sativa-side heavy seem the most likely to hold out.
When I would top plants at the end of 3 weeks veg (when they had 4-6 main stem nodes), these were more stubborn and would often fail to show preflowers until after they were flipped. When I waited until the end of week 4-5 (when robust plants had 6-8 main stem nodes) . . . even though the leaves were still showing opposite phyllotaxy, identifiable preflowers would usually develop there.
So I just quit topping them so early. I let em grow out the main stem until they give it up, then cut clones & fim, final transplant, veg 2 more weeks to let em recover, then flip. If they're gonna get too tall for your space at that point, you can always top off a few nodes rather than just the growing tip. As stated, taking clones after 1-2 weeks of 12/12 is another option - preflowers are likely to develop 3-4 nodes up the branches.
I've also noticed what I think is a correlation between the earlier development of preflowers and the earliest bud maturation . . . the ones that show strong preflowers first are usually the ones that finish first. I use this trait to ID the plants - the first girl to show becomes #1, and so on . . .
I dunno . . . could be a bunch of fertilizer . . . I wonder if anyone else has noticed anything along these lines ??
jm2c :48: