I bought a Honeycrisp 14 years ago and don’t know what rootstock it’s on but I took a picture of some suckers today, which have a distinctive red color:
In terms of characteristics, the tree is slow growing, self supporting, seems semi-dwarf, drought tolerant, and has had no real disease problems other than a bit a powdery mildew.
I know Bud rootstock is red but B9 seems too small and B118 too big. I bought this at a nursery so it would have been a common one.
Probably one of the bud rootstocks. Drought tolerant would seem more like bud 118.
IME Honeycrisp is slow growing on any rootstock.
My vote would be b118
Bud 490? Seems like that was around briefly during that time, so possible.
I’d try B490 if I had access. But probably B118, but nothing definitive.
At 14 years old and the trunk size in the picture I would say Bud9. I have a 20 year old Bud9 which looks about the same size trunk. The degree of dwarfing of the dwarf rootstocks can vary a fair amount depending on the soil, climate, etc. Also they are often self-supporting, my old Bud9-er was never staked. I only stake trees when they get tipsy.
I managed to get some scionwood last year and graft. All my bench grafts did poorly last year, but those survived. This year the bud490 grafts are looking strong, so next year Ill try bending one to the ground and covering with soil to propagate it… Hopefully the following spring Ill have a few to share.