Fungus on ash trees

[dvmcmrhp52]

We've got some ash trees that have been dropping leaves after curling up and drying on the branches.

It's now the second season that they've done this, and I've been told it's probably a fungus.

Is that what this is, and how to treat it, or simply wait it out?

 

[Urban Forester]

That appears to be Ash Anthracnose. It occurs when weather conditions are conducive to the growth of the fungus, wet springs w/high humidity. While it is a "disfiguring" foliar disease it is not (in most cases) a threshold problem. In other words it won't kill the tree. It is very difficult to control by spraying due to the fact that the treatment window is very short. Treatment should begin at budbreak and be followed up by another application 7 to 10 days later. The infection period is also short, so the need for continued spraying after 1/2 leaf expansion is useless. I try to convince most people not to even bother w/chemical control. Some years you get it, some years you don't.

 

[Ed Roland]

That appears to be Ash Anthracnose. It occurs when weather conditions are conducive to the growth of the fungus, wet springs w/high humidity. While it is a "disfiguring" foliar disease it is not (in most cases) a threshold problem. In other words it won't kill the tree. It is very difficult to control by spraying due to the fact that the treatment window is very short. Treatment should begin at budbreak and be followed up by another application 7 to 10 days later. The infection period is also short, so the need for continued spraying after 1/2 leaf expansion is useless. I try to convince most people not to even bother w/chemical control. Some years you get it, some years you don't.

interesting
The homeowner states this is the second season of like symptoms. Why not assume a polycyclic disease such as Bacterial Leaf Scorch over Ash anthracnose?

If, in fact, this is BLS then the recommendation should be: Tree Tech OTC after full leaf expansion. Never a cure but can extend life.
BLS, apparently, has not been identified north of new york city.

Have a competent pathologist identify the causal agent. Then you can ask us for the best remedy/rec.

 

[treeseer]

looks a lot more like anthracsnose than scorch. send the leaves to your extension agent if you want another opinion.

 

[Urban Forester]

interesting
The homeowner states this is the second season of like symptoms. Why not assume a polycyclic disease such as Bacterial Leaf Scorch over Ash anthracnose?
.

Having Anthracnode for 2 seasons is not uncommon, as stated weather conditons dictate fungal activity, maybe there has been 2 springs w/hi humidity and temps that are conducive to spread. I have never seen BLS symptoms that look like this. BLS effects much more of the tissue, note pocket formations of fungal growth causing leaf to twist or pull in, that is not consistent w/BLS. I believe this is a case of anthracnose

 

[Ed Roland]

Here is a picture of BLS where "note pocket formations of fungal growth causing leaf to twist or pull in" on pecan.

When we see hoof prints we have to think horses before zebras, right. So we take a close look at anthracnose and BLS in this case before testing for other disorders.

From the pics and from the description (late summer defoliator, Second season same symptoms) we could go either way. No?

Urban Forester and TreeSeer are heavy hitters on this site. I hope I challenged their wisdom in a respectful way.

have the causal agent identified from a pathologist (local extension agency).

 

[treeseer]

Urban Forester and TreeSeer are heavy hitters on this site.

O i dunno on a lot of stuff i have to bunt or punt. :censored:

 

[appalachianarbo]

Those witches brooms lower down on the branch look like classic anthracnose...

 

[Urban Forester]

O i dunno on a lot of stuff i have to bunt or punt. :censored:

I'm more of a duck and roll type...same thing though