What happened to these Ash?

[NebClimber]

I have been asked to determine cause of death of 3 Ash in eastern Nebraska. Trees started to decline 3-4 years ago, and really showed problems about 2 years ago (started dying back from tips). I see only a few exit holes typical of the ash borer, but I don't know how many I need to see to conclude borer as cause of death. Some pics are attached.

Help would be much appreciated, or some direction to further my investigation.

NebClimber

 

[NebClimber]

Another pic.

 

[xander9727]

Could be Verticillium wilt.

 

[treeseer]

test soil for salt etc.

good question Dan, sometimes it's the healthy trees that point the way to the cause of decline.

peel the bark off to check sapwood for verticillium

 

[underwor]

Check on something called Ash Yellows, used to be called Ash Decline. It is really a problem in some areas in upper plains. Usually tree starts to thin from the tips down, a lot of witches-brooms on lower branches and trunk. Branches rarely die during growing season, just don't leaf out in the spring.
With Verticillium, usually the branches die only one at a time, as in maple, not the whole top as your pictures show.

http://www.na.fs.fed.us/spfo/pubs/howtos/ht_ash/ht_ash.htm

 

[NebClimber]

Anybody have the name and number of a good lab where I can send samples?

 

[Kneejerk Bombas]

Was there a drought about the time they began to decline?

 

[underwor]

CAll the Shelterbelt lab in Lincoln at UNL. They can direct you.

 

[NebClimber]

Looks like cause of death for these trees was the herbicide used to spray the fenceline. The product used is referred to as a "bare earth" herbicide. I won't list the product name b/c I can't be 100 percent sure it is the culprit, but I am reasonably certain it caused death in this case.

Now client wants to switch to a new herbicide for miles of fenceline control, w/o killing more trees. Any recommendations?

NebClimber

 

[Stumper]

I started from the top-when the first picture loaded I thought-herbicide poisoning. I'm glad that my diagnosing skills approached those of the esteemed TreeCo.

 

[NebClimber]

A herbicide named Pr am itol was sprayed along the fenceline in 1993 and 1994. Recently, the client switched to Sa har a. Tree decline conincided with Pra mi tol application. Both are described as "bare earth" treatments.

I've decided to name the product to add to knowledge base / debate / discussion.

Dripline of trees in question extended to point of application.

NebClimber

 

[treeseer]

Good references are "Herbicide Injury to Trees and Shrubs: A Pictorial Guide to Symptom Diagnosis" by Derr and Appleton, which I think is out of print, and "Abiotic Disorders of Landscape Plants: A Diagnostic Guide" by Costello, It is available at http://anrcatalog.ucdavis.edu/InOrder/Shop/Shop.asp for $35.00, or the ISA for $42.50.