You can't maintain apical dominance when competing scaffolds are nearly the same diameter as the the leader. Those upper scaffolds appear excessively vigorous as a result of excessive diameter and will probably best be removed next dormant pruning.

Relative diameter represents relative access to the root system (water, N. and other nutrients) the greater the diameter the more access. It is difficult to subdue growth of scaffolds like those although if you really want to keep them you can pinch all new growth back this season. Never works for me, but should in theory if you stay on top of it long enough (like 2 years or something).

You seem determined to get trees trained in a very specific time frame, but trees usually have other ideas. I suspect those scaffolds should have been removed during dormant pruning which is what I'd do next time. I don't think 32 inches is enough distance anyway- I'd give them almost another foot myself if the trees are on something at least as vigorous as M7. I like my trees pretty open.

In the end, you are better off removing any scaffolds more than half the diameter of the trunk at the point the scaffold is attached (to the trunk). I generally remove anything more than a third with a vigorous grower like Jonagold. I'm talking about dormant pruning here.

During the growing season you might want to start to choose 3 peramanent scaffolds for the first tier (I prefer 3 over 4 on Jonagold because of its relative vigor). Pinch back growth on the temporary branches. Once the permanent ones have dominance you probably could start pinching them a bit to develop secondary branches as you thin out the temperaries. Follow the same ratio rule with secondaries as I suggest for scaffolds and maintain a central leader on your scaffolds as well with much thinner laterals coming off it.

Looks like you're doing a great job of getting trees to grow.

Thanks Hman: yep, it is on M7. I do aim to train in a specific time frame and am learning that some trees have different ideas than I do, actually they all do.

The ones labeled "second scaffold set" were developed this year. Like all the 3rd leaf trees planted nearby, the Jonagold is vigorous enough for me but not too excessively. The bottom set (3 branches) is very nicely formed though a little higher would have been handy. It is difficult to see them as there is a lot of secondary growth coming off of them. Are you saying the second set should be removed during the dormant season? I assume you are getting at the need for more space between scaffold sets and obviously dominance.

All of my 8 trees in 2nd and 3rd leaf have been growing very well with no fert since the beginning with one exception. The Golden Russet has developed a Fe and/or Zn and/or Mn deficiency. The topsoil is 42" deep but calcareous, pH 7.2 with a "Hi" lime content. I haven't decided wether or not to amend the soil with S yet or see if the tree grows out of it as it's neighbors seem to be doing just fine.