Pathological Input Required....

[tshanefreeman]

I have a customer with a Bur Oak (Quercus marcocarpa) that has just recently taken a turn for the worse.

I will briefly describe its environment and some of the visible foliar characteristics to help shed some light on the problem. I will also provide a few pictures that should make sense of my text descriptions. Any input would be greatly appreciated.

As previously mentioned, the infected tree is a mature Bur Oak. It is growing amongst other Q. marcocarpa that are not affected.........within feet. The leaves are all curling and shrivelled. There is obvious marginal necrosis. Chlorophyll only remaining in the veins of the leaves. There is no streaking in the cambial region. Please make reference to the following pictures.

I can't see how spray drift could be an issue here. If so, the adjacent oaks would and/or should be affected too. I was investigating the probability of nutrient deficiency, but all the trees are sharing the same root zone, so experience shows that all 'should' have similar signs.

Thanks in advance for any new angles and input.

 

[tshanefreeman]

A little closer up.....

A little closer up.....

 

[tshanefreeman]

Cambial Image

Hope that these images aren't causing too much frustration when downloading!

 

[spacemule]

Here's your pics resized to a reasonable level.

 

[underwor]

Is this tree the same size as the rest? Getting crowded out? Since it is marginal necrosis, the problem is most likely lack of moisture from the root system. Is there any sort of root rot, affecting a weakened tree?

 

[tshanefreeman]

The tree may be getting crowded.......slightly. The relative dbh is within inches of the neighboring trees. The probability of moisture stress seems unlikely due to the abundance of rain that we have received this spring/summer. However, if root rot is the case, this could perhaps explain the state of the this tree.

I will have to do a more thorough root flair excavation to see the overall state.

Thanks for this angle to approach.

 

[treeseer]

a more thorough root flair excavation.

Root Collar Examination; RCE is Job #1.

 

[John Paul Sanborn]

There are some fungal problems that express that way, the above is Apiognomonia or oak anthracnose. Though this is a cool wet problem in spring. Are you sure thay have not been like that for while? (this begs the joke that it was spring last week up there)

 

[underwor]

JPS,

You are closer than you think. We have had about 3" above the average rainfall for the year since about mid May. About 20+ inches so far. I forgot anthracnose, but I think his photos lack the spotty look of the fungus. There was some anthracnose this spring, but we had a few 90+ degree days and that shut it down in the ash trees.