# Canker on my Maple



## dlew (Jun 10, 2010)

Not an arborist, just a weekend hack -- hope y'all don't mind questions from mere mortals. 

I have a Maple (October Glory) that's been in the ground for four years and, in the second year, I noticed a small divot on the trunk. I scraped it with my thumbnail and it was fairly moist. Fast forward a few years and it's gotten quite a bit larger. I have no idea what to do about it but my Father in Law, who's in the field, suggested that I post something on line. So, here I am! Any idea what could be causing this or if anything can be done about it?


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## S Mc (Jun 10, 2010)

dlew, welcome to the site...not a problem with questions from mere mortals, as long as you don't mind hearing answers from same. 

Could you stand back and take a picture of the entire tree to give us a bit of perspective?

Many times when a tree sustains an abiotic injury, be it sunscald, mechanical injury from a scrape or bump, the surrounding tissue will die as well, just not right away. Often what we initially see is not the full extent of the actual injured tissue. As the area begins to seal over, the outer cambium will slough and the whole will look larger than our first perception. 

This actually looks like two cankers that may have connecting damaged tissue under the bark. What compass direction is this injury? Northern California, depending on where you are, may still have conditions that cause sunscald.

Sylvia


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## treevet (Jun 11, 2010)

Looks like a flush cut and related dead spot.


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## dlew (Jun 12, 2010)

The wound is pretty much due East and we live in a town that gets pretty darn hot -- I can understand it being a sun/heat related thing. I'll try to get a pic of the tree up tomorrow.


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## elmnut (Jun 19, 2010)

nectria canker, maybe.


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## StihlyinEly (Jun 21, 2010)

elmnut said:


> nectria canker, maybe.



Agreed.

Could very well have started with a branch pruned too close to the trunk for the tree to heal the wound. However it started, sure looks like some form of canker.

No chemical control measures work on it that I know of once the nectria canker is present. Likely it continues because the tree is/was stressed in some way. Too much water, not enough water, root damage by digging, competition with adjacent trees, etc. If it occurs in branches, you remove the branch during a dry spell toward the end of the tree's dormant phase. With canker on the trunk like that, I dunno. 

Try finding out why the tree is stressed, and remedy the stress. The tree is trying to fight back and might be successful if the stress is removed.


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