Hi all,

We have an apple tree in our back yard, no idea the age, but it's pretty large so I'm guessing over 20 years.

It's got 4 big branches coming off the trunk. We've noticed bark flaking off the last few years. Mostly on one of the 4 main branches. This spring,that branch didn't develop almost any leaves. We were inspecting it today and I was planning on cutting it off as it seemed dead.Then my wife pushed on it a bit and we heard it crack. It was totally rotted/spongy in the center. I was able to break it off with little effort.

I'm guessing this may be "sappy bark" and due to the location, is probably fatal to the tree but wanted to check if there is anything I can do to try to keep it going. Is there anything I can put on this large open wound to prevent further infection? I have several different fungicides for my grapes and veggies.

Closeup of wound:

Dead branch:

This was the tree last fall. The dead branch is the one on the left.

It's never been a big apple producer in the 6 years we've been here, but last year was actually it's best year for us. this year looks like quite a lot less.

Any thoughts?