sycamore leaf disease

[Vox Humana]

I have a sycamore that develops the same problem each spring. The leaves are just fine then develop small spikes on the top surface. The margin of the leaf seems to be most effected. Eventually the leaves distort and fall off. The tree also develops anthracnose later in the year. Neither disease seems to be killing the tree. While I have searched Google for ideas, I can't find anything that seem relevant. I posted some pictures to alt.binaries.pictures.garden under the title: "Sycamore disease ID request"

[bamboo]

There is a mite too small to see called the "eriophyid mite" Most likely culprit for your leaf pimples. My instructor used to say these were named by someone in love with vowells. How would you recognize a sycamore in the treeline if the leaves didn't all fall off?:)

[bamboo]

There is a mite too small to see called the "eriophyid mite" Most likely culprit for your leaf pimples. My instructor used to say these were named by someone in love with vowells. How would you recognize a sycamore in the treeline if the leaves didn't all fall off?:)

[Doug Kanter]

At my previous home, the sycamore had that problem, although not in all years. I don't recall the name of the syndrome. In one or two years, when we first moved there, we paid some tree expert to put little injection things into the tree. It didn't help. Then, we called the NY cooperative extension, and a guy told us that the best way to help the tree was:

1) Clean up all the fallen leaves, especially in autumn. Bag them and get rid of them. Don't compost them unless you can use a two-stage (2 bin) method, on big property, pretty far from the tree, and make really sure the compost's reaching the right temperature. Naturally, we raked the lawn in the fall, but I liked to leave some in the flower beds as winter mulch. He said to forget that idea. It harbors the spores or whatever. 2) Help the tree during long, dry spells, by thoroughly watering, very deeply, out at the drip line.

There'll still be some ugly years, but if our tree was any indication, it didn't seem to suffer in the 20 years we lived with it. And, it was about 30 years old when we arrived.