I was bored yesterday so I went back to some old post and read one about node count. I have a basic understanding and have a question. When the tree gets to the node count (lets say 900) it can then bloom and fruit, then you cut all the limbs you loose the number of nodes and the tree can no longer flower or fruit. What if you get a new limb started on the trunk after 900 nodes and then you cut all other limbs, does the new limb start over or does it continue at 900 nodes and greater? Thanks Jack

It does continue to increase the node count: 901, 902, and so on. By cutting the lateral limbs you don't decrease the node count anyway.

I think node count is actually remembered per-node and radiates outward, so only number of buds from the first (trunk/soil line) matters. I think total node count is just an approximation of the number of overall nodes once the first branch/bud reaches maturity anywhere on the tree. Once the node count is reached in a bud it triggers a permanent cell differentiation that is inherited to all child buds, which is why you can graft a single bud from fruiting wood onto an immature rootstock tree.

If, instead, a magic number of total nodes on the tree overall is what mattered, it seems like you could graft a new seedling onto mature wood and have it fruit the seed variety, which is not the case. Or, apply some kind of hormone to force maturity. I've read some speculation that an unknown chemical dubbed "floriden" is part of process but it sounds like bunk.

From http://www.gardenguides.com/79887-causes-flowers-bloom.html
"Theory holds that a flower-inducing plant hormone called floriden is the physical mechanism within a plant that causes flowering. There is strong evidence this theory is correct, but studies on it continue."

I don't think this is credible at all, but I'm no expert.

Brian, I don't really understand what you are trying to say. But as far asdolfanjack question, if the new limb sprouted out from the trunk above where the tree had already became mature, the new sprout would be a mature limb and could flower and fruit. If the new limb sprouted near the bottom of the trunk then it would be immature with a low node count and unable to flower and fruit. . - Millet