Sick ash tree. (Possible fungus?)

[austior]

The leaves are browning and falling off much earlier than another tree of the same type. This happened last year as well, but this year it's much worse. You can see the two trees in the first photo. I also took a look at the leaves at 40x magnification. All of them have the black thingies seen in picture 4, maybe it's just dirt, and some have the white fuzz in picture 3, though I have no idea if this is part of the problem. The trunk and branches all look healthy.

This may be too much information, but we want to be sure before treating the tree!

 

[Raintree]

Ash leaf spot most likely Mycosphaerella, no controls. Disease can be reduced by removing fallen leaves, pruning to help increase air circulation. White webbing may be mites. What is different about the tree on the left, buried root collar, soil compaction, etc? Stressed trees are prone to dysfunctions.

 

[austior]

Thanks for the reply! When you say "no controls", do you mean there's no chemical treatment? I will check the trees tonight to see if there are any differences.

 

[ATH]

Where are you located? Throughout much of the Midwest, heading into New England, Emerald Ash Borer has made all other ash pests irrelevant.

 

[austior]

What is different about the tree on the left, buried root collar, soil compaction, etc?

The tree on the left is smaller and also nearer to a retaining wall (about 15 feet). Other than that I see no differences, though I don't know how to check for soil compaction. I found a leaf today that was covered with both black and yellow spots, very tiny, almost like a dust.

Where are you located? Throughout much of the Midwest, heading into New England, Emerald Ash Borer has made all other ash pests irrelevant.

I'm in southeastern South Dakota. Supposedly they aren't here yet, though it may be only a matter of time.

 

[Raintree]

If you can post up a pic of the stump area. Was the wall installed after the tree was established? Compromised root zone is a common stresser. Any drainage or septic activity on that side? Tiny yellow leaf speckling may be a indication of mite feeding.

 

[austior]

If you can post up a pic of the stump area. Was the wall installed after the tree was established? Compromised root zone is a common stresser. Any drainage or septic activity on that side? Tiny yellow leaf speckling may be a indication of mite feeding.

We acquired the house 7 years ago and the tree seemed to be healthy for the first 5, but I'm not sure when the retaining wall was built. I don't think the yellow spots are from mites, take a look at the last picture.

 

[Raintree]

The stump looks good, I don't see the wall in relation to the tree.

Do a quick test for mite activity:

A good way to tell if you have mites is to wipe a white cloth or tissue over both sides of a leaf of a plant suspected of mite infestation. If mites or their eggs are present, reddish or brownish streaks will be seen on the cloth. Another test is to tap a leaf over a piece of white paper and see if any of the dislodged particles move. A good magnifying glass is recommended with this test.

 

[austior]

The stump looks good, I don't see the wall in relation to the tree.

Do a quick test for mite activity:

We're having some rain here, so I haven't had a chance to do the test. If it were mites, is that something we'd want to treat for? Thanks again for all the help!

 

[Raintree]

If it is mites, I would recommend a dormant oil spray to help suppress the overwintering eggs. In the mean time get a soil analysis done to rule out fertility issues (PH & nutrients).

 

[Roots Growmore]

Definitely treat for mites right away before the infestation grows. Then healthy pruning and mulching to build the tree up again!