Is this nectria canker?

[tomacripps]

Hi all,

 

New to the forum today, having attended a tree survey training session with the Woodland Trust, which I found absolutely fascinating.

 

I got home and decided to inspect the huge ash tree at the bottom of my garden. Having not really seen it before, I couldn't tell if this (see attached image) is canker, or just where a branch has fallen/been chopped off, does anybody know?

 

Thanks,

 

Tom

[sloth]

Not the clearest of pics, but sure that's an old pruning wound, the 'ring' around it is new growth since the cut was made. The tree will eventually seal off the wound providing, hopefully, a continuity of strength as the wood behind the pruning cut decays.

[Gary Prentice]

Another indication that it is a pruning wound is the branch branch ridge. These aren't always so prominent on every species.

[tomacripps]

Thanks to you both for your replies.

Apologies for the photo quality, I snapped it with my phone and it was quite high up in the tree.

 

I'm glad to hear its not canker. As for the bark branch ridge, why would this not also appear at the edge of a canker wound?

[sloth]

Have a look at some tree branches which are still attached to the trunk, you'll notice on some trees there is a ridge of congested bark where the top of the branch meets the trunk. Simply put this is where the trees 'fibres' are diverted around the branch, hence 'branch bark ridge' (bbr). It is more noticeable on some trees or species (such as ash, or birch) than others, and it is completely normal.

As a side note tree surgeons will use it as a guide when making a correctly positioned pruning cut, which should leave the bbr intact.