Apple tree issue

Hello all,
I have a pretty old apple tree in my yard that has multiple issues. This issue is a deep hole in the main junction of the trunk. It looks like there is a decent among of rot and it is quite large. Im concerned it will at some point kill the tree. Is there anything that can be done? A treatment of some kind perhaps. I've even thought of filling it with epoxy! Any help would be greatly appreciated!

Hi Chris,
Welcome to Permies!

I am not an expert, so take this with a grain of salt. But I would try to make sure there was a way for the water to drain, and not sit in the spot and increase the rot. At a previous house, I had an old apple tree that was easily 100 years old... if not 150. It was hollow in the middle, and was still doing fairly well. With some tending it even produced apples. Some apples trees are pretty tenacious.