Sycamore dieback

[Bounce]

This is something that I have never seen before, and is now happening to every single sycamore tree I've seen in the last 3-4 months in several cities in wet and dry climates throughout Washington State. I haven't been able to find out very much info about this online and was wondering if anybody could tell me more about it. The biggest thing I need to know is whether this is fatal or not, but I'm also interested to know what causes it and if there are any known treatments.

 

[canadiantreeman]

Is it anthracnose, or is it out of season by now? I have noticed a few up here which are defoliated like that as well.

It's interesting that the tips are not defoliated, which is probably a clue to the identity of the culprit.

Anthracnose is fatal in some instances, but a tree also may be able to produce a second surge to replace the lost food factories. Don't write em off this year, see how they do next year.

 

[Bounce]

Some more info: the remaining branches don't appear to be dead. At least when I last checked they were still green and flexible. The foliage has just simply all fallen off except for the highest tippy tops. The tree in this picture is approx 100 years old, but I've also seen it in seedlings and everything in between. Trees are exhibiting this symptom pretty much everywhere, from the driest of desert climates to the wettest of coastal climates. There doesn't seem to be a single sycamore that is unaffected.

 

[canadiantreeman]

http://www.na.fs.fed.us/spfo/pubs/fidls/anthracnose_east/fidl-ae.htm

 

[Burnham]

That's a bummer.

 

[sotc]

Dylan has likely nailed it. Fungicides labeled for anthracnose work if timed right. This year has been very bad for fungal issues

 

[jefflovstrom@sb]

Hi,
Have you ruled out 'Xylella fastidiosa?
http://urbanext.illinois.edu/hortanswers/detailproblem.cfm?PathogenID=84
I have not seen it kill a syc., but sure makes them ugly when you cut it out.
We saw that other plants and shrubs nearby were stressed.

 

[jefflovstrom@sb]

Dylan has likely nailed it. Fungicides labeled for anthracnose work if timed right. This year has been very bad for fungal issues

I would not rule out another fungal problem after one started it before. Anthracnose would show the opposite symptom. Inside-out v/s outside-in.

 

[jefflovstrom@sb]

I am a 'sophist'.
Jeff

 

[canadiantreeman]

Anthracnose would show the opposite symptom. Inside-out v/s outside-in.

What does that mean?

Another fungal problem being present before anthracnose is possible, but what are the symptoms? All we see is defoliation. The link you posted is for bacterial leaf scorch, which states:

"In sycamore, symptomatic leaves curl upward but remain attached. Initially a single branch develops leaf scorch symptoms. Symptoms recur each year, with an increase in the number of branches affected"

I wonder if the tree has retained its leaves...

 

[sotc]

He means typically the outside of the canopy loses leaves first. That is typical and rarely is anthracnose the only fungal pest in the tree so of course it could be several things but the most common is worth the first look

 

[sotc]

That said, I installed a couple anthracnose resistant London plane the other day, nicest looking I have seen in a loooong time, going to keep my eyes on them for the next several years

 

[NickfromWI]

http://www.na.fs.fed.us/spfo/pubs/fidls/anthracnose_east/fidl-ae.htm

Thanks for posting this. I deserve 1/2 a CEU just for reading it!

 

[Bounce]

It could be anthracnose, but I don't think so. For starters, I've never seen fungus diseases like that on trees in the dry desert climate of eastern Washington. And in the wetter climates where I do see it, it is usually not perfectly uniform. The damage is usually concentrated in one part of the tree (often the lower branches close to the ground where rain splash can get soil onto the foliage, or on the interior canopy where humidity is highest and air movement the poorest). What I'm seeing is exactly the same pattern of damage on every single plant, regardless of age/size, climate, location, etc. Every single tree has lost all of it's leaves right up to the tips of the tallest branches. The dead leaves have all fallen off and look just the way they would in the fall, with no visible curling/spot deformities like Anthracnose causes.

What is so confusing to me is that defoliation like this is often a sign of not enough water, but we just got done with one of the wettest winters and springs on record for the PNW. Many plants are several weeks behind their normal annual growth cycle due to an exceptionally wet and cool spring.

 

[Bounce]

That's a bummer.

Excellent diagnosis Dr. Chamberlain! Your honorary BCMA is in the mail.

 

[Burnham]

 

[sotc]

Send out a tissue sample