Perhaps verticillium wilt, a soil borne disease. Use a sharp tool to make a cross-sectional cut and some longitudinal cuts (like you were whittling on the affected branch). If you see greenish streaks or bands that follow the grain in sapwood, or vascular discoloration in rings or rays, consider them likely symptoms of the disease.

Al

Thanks for the info Al. I did a google search and found a link for the most common diseases. I noticed this 2 summers ago. Last summer the leaves got better but not by much. Not sure what I will do about this? It says try to trim the affected areas away and hope for the best.