Perennial target & other Cankers

[David Humphries]

a thread the other day got me to thinking about what's been posted up on this issue in the past (not alot from what I can gather)

 

http://arbtalk.co.uk/forum/tree-health-care/70269-help-damage-limes.html

 

 

Definiton; fungal associated die back of the bark and cambium on stems (sometimes on branches) showing as a 'target' where annual callus material is layed down in an attempt to compartmentalize the infected area.

 

Often focused at a point of a failed branch attachment or stub.

 

Caused by Nectria and other fungal canker sp (and less so by bacteria sp)

 

(various resources; Butin, Lonsdale)

 

 

Here on a Horse chestnut at work, which I've probably posted in the past on other threads.

 

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[David Humphries]

I've noted it before, but not really given it a lot of thought.

 

More than likely to be superficial as a stability issue but worth considering on an individual basis depending on degree of circumference infected.

 

Here on Ash on a boundary veteran in Worcestershire.

 

 

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[David Humphries]

here's a substantial perennial canker on an oak branch which led us to reduce the height of the affected branch.

 

 

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[David Humphries]

More than likely to be superficial as a stability issue but worth considering on an individual basis depending on degree of circumference infected.

 

here's a roadside Prunus that would have me looking a bit closer if I was managing it.

 

 

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[David Humphries]

Anyone have experiences/images of failures associated with these type of cankers?

 

 

 

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[armybloke]

David, referring to picture one. I have seen this canker before where a limb from a tree in proximity caused it to callus after abrading. The offending limb fell or was removed and this was the result. Is this the same sort of issue? I will see if I can remember where I saw this recently a post a pic.

Cankers are a response to an irritation is it not? A bit like a hard skin on a human? Or am I assuming....

[Gary Prentice]

Anyone have experiences/images of failures associated with these type of cankers?

 

 

 

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Can't say I have had any experiences of failures due to these , that I can recollect anyway .

[JonnyVine]

Anyone have experiences/images of failures associated with these type of cankers?

 

Anyone have experiences/images of failures associated with these type of cankers?

 

I don't think I would be getting exited over the first image David, it's in the middle of the "neutral fibre" so should not represent too much of a problem, clearly it has been there a good 30 years.

 

I would share your concern about the roadside Prunus however.

 

Personaly, unless the target takes on an exessively flat profile or is in a hotspot

I think its safe to just "tap and probe" them for most locations.

 

Beautiful example by the way.

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[David Humphries]

I have absolutely no management concerns over the first set of images of the Chestnut Jonny.

 

It's in woodland and even if it was of more concern regarding its profile it's protected by surrounding canopies.

 

I merely posted it as a thread starter as you quite rightly suggest, it's a fine example

 

 

 

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[Tony Croft aka hamadryad]

Not forgetting to mention the annual infection of the occluding tissues being the cause of the target like appearance, and lack of successful occlusion.