Dark inner wood on Acer campestre: Bad news?

Carl_Bergstrom

Hello everyone,

When I chopped the leader off an otherwise healthy field maple Acer campestre, this is what I found (see the dark "star" in the center of the wound.) Could this be verticillium wilt? I thought the staining usually was in a ring - but could this be the same thing? Or do you have any other guesses as to what it may be, harmful or otherwise?

Best regards,
Carl

Attached Images

2005_02_chop_closeup.jpg (21.6 KB, 43 views)

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JohnQuinn

Carl, I did find some images that are not unlike your irregular outline...

http://aggie-horticulture.tamu.edu/.../stem/24.3.html

ALDEVAUX

It does not look completely like Veticillium wilt because the most important symptom of this disease it the discoloration of the xylem tissues which are just under the bark, and of course the wilting of the infected branch.
It looks more to me like heart rot which is usually caused by a fungus that inters through wounds as explained in this reference :

http://forestry.about.com/od/forest.../dis_com_hr.htm

The only way to be sure is to have the pathogen isolated and identified by a plant pathologist in a plant disease diagnostic laboratory.

rockm

Carl,

I don't think this is V. wilt-or if it (was) it's not a problem now.

I've had Vert. wilt disease kill a couple maples. The dark stains are of concern ONLY if they're out near the edge in living tissue, as Aldeveaux says. If this stain had been in the outer third of the trunk, then you should be concerned. The outer tissue looks excellent in your cross section.

Discoloration of the interior of the trunk, especially that far inside, is of little concern. It is dead tissue and really of no use, except for support of the tree. If this was V. wilt, the dakr pattern might indicate the tree simply "outgrew" the disease, which is one of the only ways a tree can "beat" the V. wilt infection.

I'd go with Aldeveaux's "heart rot" theory.

Carl_Bergstrom

Al and Mark,

Thank you both for your answers! I'm relieved to hear that you don't consider verticillium wilt to be the most likely explanation and I appreciate your detailed descriptions of the alternative possibilities.

With gratitude,
Carl

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Will_Heath

What a refreshing textbook example of how to take solicited advice!

Deciduous Tree Diseases

http://www.ext.nodak.edu/extpubs/pl...rop/pp697-1.htm

It would appear that you have some heart rot Carl, donating to Charity's, spending more time with your family, and plenty of exercise might help.

Seriously, as the above link states, "As long as the tree is growing vigorously the rot will be confined to a small central core of the trunk and the structural integrity of the tree will be maintained."


Will

Carl_Bergstrom

Not likely, Will.

Stone don't rot.

-Carl

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