Think plum tree has canker

[w33blegurl]

Afternoon! Our plum tree which has been in the garden for around 12 years is starting to look very sad. One branch is looking a bit like it's dying back and the leaves have all gone yellow. I can see at least one "sore" type wound on that branch (as well as cracks on some other branches) and am wondering if this might be the start of canker? I've included a few pics so you can see what I mean.

If anyone can confirm (or deny with a different explanation) that would be great. I assume if canker, we need to take that branch out ASAP? Might it still spread or should we simply be removing the whole tree at this stage?
Thanks!

[nickdub]

Well, as you say the branch with the yellow leaves is dying off. I'm not going to try to diagnose what's causing this, but to me it doesn't matter as the only thing to be done is to cut that branch off as close to the trunk as possible. To do this I'd cut the thinner bit of the branch off first with secateurs to remove some weight - then use a pruning saw or a bow say, first to cut below the branch slightly then from above getting as near to the trunk as possible a - and finally use a sharp knife to clean up the sawn bark to as smooth surface as possible.

If whatever infection is killing the branch has already spread to the trunk, then the likelihood is the rest of the tree will die in the next couple of years, - if not then it may make a complete recovery. BTW if it's a favourite sort of plum for you then you may be able to take a small section of new growth from a healthy branch and chip bud it on to another plum tree, either in your own or a friend's garden and so have something to propagate from again in the future.

[w33blegurl]

Thanks for that. it confirms my thoughts, ie lop it off and see what happens. It's only a bog standard Victoria plum so I'm not too attached to it. If it all goes, I'll just plant a new one down at the lottie (this one's in our garden).

[ameno]

That probably is a canker sore, however I'm not sure that that's what is killing the branch. Canker is not fatal in and of itself - in order to kill a branch, it needs to girdle the whole branch, thus cutting off all water and food supply. But that canker doesn't seem to have done that, so it shouldn't have killed the branch, which makes me suspect something else may also be at work here, and maybe the canker is getting in as a secondary infection in a weakened tree.

Either way, as said above, the dying branch should be removed in its entirety, posthaste.

[GF3]

Hello.
I thought it would be best to "muscle in" on this post rather than start a new one.
My question is the same.
Is this canker on a plume tree.
I got it as a bare root tree (variety: Blue Tit) in late November 2019. It has been in a container since. It will be going into the ground when I have finished preparing the garden.
The tree looks fine, plenty of growth. But I spoted this patch just above the graft point.
Many thanks

[ameno]

It's hard to be 100% certain, but that doesn't look like canker to me. Rather, it looks like something sliced off a section of bark from the trunk, and that's just the natural healing process at work there.

[nickdub]

I agree with Ameno, and it looks to be healing nicely. Don't forget to feed it once a week or so while its still in a pot.

[GF3]

Thanks for your replies.
When I planted the tree in the container I did add Bonemeal at the time. And in April I added some Westland "Gro-Sure" Slow Release Plant Food. On the pack it says "Feeds For 6 Months". Would you consider that to be enough? Or should I be thinking of adding something else too?
Thanks again.

[nickdub]

As far as feeding goes, I'd say "ask the tree" - if it has good large dark green leaves and has made new growth, its probably got plenty of feed to be going on with, if not then it may need a bit extra.