So I bought 3 fruit trees from Stark bros. I think it was over 200 dollars for the trees total. One I had growing in the dog kennel where it was eaten. The second I had under netting. I had them growing in pots on cement so there is no tracks. Both trees main stem was fully broken. The branches on the final one have been taken off on the top. What could have done this and how to protect against it. I thought the netting would protect it but whatever it was could figured out how to get under the netting. My theory is the diameter or trees Stark Bros sent was just too small so animals could break it as it was super small diameter. I bought the replacements from Bay Laurel because I know most of their stuff is 2/3 inch so hoping that will help.
I would suggest the wire cages put around the outside of the trees. They are about 4 foot in height. I believe St. Lawrence Nursery sells them and I am sure there are other places that sell them or you could make some as well.
There are reports that the dwarf trees can snap at the graft area. I have had a couple of dwarf trees do that. Only the dwarf ones have broken, at least for me. One I pushed it to straighten it up to adjust the strap for the stake. I was not pushing hard but only to adjust the rubber strap some. The other one we had a wind storm and broke it right at the graft.
I would suggest looking at this thread dealing with cages for trees. It could be deer are browsing on the trees. I don’t think larger caliper trees are going to be much help if your problem is deer.