Thanks guys.
Rick, our sandy soil and high deer densities keep invasive shrubs at bay. I think it's just too dry for most to survive. we do have some Bush honeysuckle but they are only found under large trees (typically jackpine). if they can hide in the shade they might survive. Overall they are not a threat.
my father is very dedicated to keeping invasives off our land. he regularly fights Knapp weed, poke weed, garlic mustard, St Johns wort. even common mullen. Probably a few other things but he uses a lot of round up annually spot spraying. through our efforts we have maintained a pretty clean environment, not to mention we really encourage native plants to dominate our landscape. we have planted so much native grasses and wild flowers we just keep encouraging those to take over.
so far I'm happy with my orchard. with a fine tuned process b118 have done well in our sandy soil. I have tried to be aggressive with training in the early years. however with the little kids I haven't had much time this year so well see how things go. I might just have to do careful thinning cuts to remove the bad angles etc.