Is this crown rot on my Apple tree?

[Jsguitar]

Hi,

I have four semi dwarf apple trees planted in a line that slopes southward in my backyard. This Liberty apple tree is on unknown rootstock from Stark Bros and is going on it's third year. It's the lowest tree on the slope and mulch washed onto its collar for some time before I noticed. I pulled all of the mulch back and created some ways for water to drain better but it looks pretty bad to me. My other trees look normal. I'm wondering if I'm going to have to pull this tree out. It could've also been abraded by some debris (more mistakes). Thanks for looking and any advice.

James

I can't seem to get the pictures to attach, will try later.

 

[Jsguitar]

Here's a few pictures.

 

[YumYum]

Isn't that where the graft meets the rootstock?
Maybe because the mulch was covering it, it was basically trying to reroot there.

I wouldn't dig it up unless I was for sure it was dead.

 

[Jsguitar]

Yes, the questionable looking area is on the rootstock right up to the graft union. I plan on just keeping an eye on it. The tree is budding fine right now. I'm just worried it might get worse and I'll end up chasing a problem. Hopefully not.

Edit: Maybe that is a bit above the graft too actually. I was thinking it was just the rootstock but it does look like it's damaged above that too. I'm not sure.