Exactly with spikes. This one linked is for raccoons. You’d need to keep scaffolding branches 6 ft off the grounds with spiked collar but it can be done.
And bears love persimmons. Prok persimmon is self fertile, virtually no maintenance, prolific and it’s leaves are awesome in the fall. All around winner.
Bears can still jump and rip down limbs so electric fencing is the only thing that works for sure, from what I understand.