Fungus?

[bstewert]

Anthracnose?

 

[gf beranek]

It's usually a spring phenomena in my latitude. How old are those pics?

 

[bstewert]

I took them in mid August, but that's not to say the leaves were like that all summer.

 

[gf beranek]

Please give an update if or when you find out exactly what it is. Thanks

 

[Jomo]

Powdery mildew, a fungus. Works hand in hand with anthracnose.

http://auf.isa-arbor.com/request.asp?JournalID=1&ArticleID=2503&Type=2

Jomo

 

[bstewert]

There is no "powder" on the leaf at all, like all the powdery mildew I have seen. Plus there are portions of the leaf remaining intact, which doesn't seem to be characteristic of powdery mildew.

 

[Jomo]

Do you have a local county agricultural pathology lab that'll ID from a bagged leaf sample?

Our local county ag dept does it for free here.

Good luck.

Jomo