I’ve been curious about this as well, partly from an understanding that dwarfing rootstocks are generally inhibited in accessing nutrients, both in their physical reach, but also in relation to specific minerals (and obviously all manner of biological soil interactions). As far as I see it, this is the #1 drawback of dwarf rootstocks, so the question is certainly legitimate. I have an Antonovka tree grown from seed (Antonovka seedlings are said to be more true to type) that grew to a whopping 10 feet tall in its 2nd season. Unfortunately, it was in a nursery bed so had to be transplanted. I’m sure I lost a pretty good chunk of tap root, etc. I trimmed the tree back to about 8 ft. at transplant, and it has taken two additional seasons to regain those two feet. Neither does it appear as healthy as it did before transplant. Clearly, seeding-in-place is an additional consideration on top of allowing a tree to grow it’s own roots vs. grafting onto something other than seedling rootstock.

Here are my questions about seedlings for commercial fresh market production:

• Assuming that we would be working with a much larger canopy (and much less photosynthesis happening in the inner canopy), how would one deal with the inevitable loss of color, size, and flavor you would expect from fruit in the inner canopy?
• How would one compensate for the massive increase in labor for pruning, harvesting, thinning, and any other hand work that might be necessary?
• In my region (SE Pennsylvania), I would be very concerned about disease from lingering moisture trapped in the inner canopy.
• Given the above considerations, might this best be applied to an orchard designed specifically for cider?

It seems a difficult fit for commercial production, but it often bugs me that in growing dwarf apple trees, I am working with trees that are fundamentally flawed in regards to nutrient accumulation.