Several MAIA (Midwest Apple Improvement Association) members plant out seedling apple trees every spring for evaluation. As MAIA members our farm has been doing this for nearly twenty years and we’ve noticed that a tree that produces fruit favorable for our purposes (generally fresh consumption and keeping quality but also bloom date and disease resistance) may grow a bit differently on a dwarfing rootstock. Cornell is currently researching dwarfing apple rootstocks and their abilities to assimilate and distribute nutrients. Nutrient uptake differences between rootstocks is significant, but I don’t believe they have compared these dwarfing rootstocks to seedling. I’ll look into it, I’m curious..