Question
I have a mature subject tree that has some branches at the upper level where the leaves are completely dark brown. I have been watching this process and I see more and more branches of leaves turning brown.
Is this tree dying or is their any treatment for it??

Answer
Don:
From your description, this may be a common disease that we see here in my part of the world called fire blight.  It is caused by a bacterium and starts usually on the twig tip area where leaves turn dark brown to black and continues back toward the main stem.  It usually occurs in a random/scattered fashion on the tree.

I am sending you a link to an information bulletin that I produced on this disease.  It is a pdf file, so you will need a free program on your computer called Adobe Reader to open it.

http://www.uaex.edu/Other_Areas/publications/PDF/FSA-7534.pdf

Let me know if this information matches your symptoms. Also, you can "Google" fire blight to get some information.

Regards
Steve