Plum (Non Bearing) Leaf Scald

 Xylella fastidiosa.
The bacterium clogs water-conducting xylem cells and is
associated with a leaf scald.

Symptoms begin as a fading or bronzing along the margins or tips of leaves. Leaf tissue soon dies and becomes a dry brown. Leaves may die inward from the margin in several steps. The symptoms may begin on a single branch, but eventually the entire tree will be affected. Symptomatic leaves will drop in late summer.
Additional symptoms include,  of these are; nutrient deficiency or toxicity, drought stress, herbicide poisoning, root death or a delayed reaction to winter cold damage.

Infected peach and plum trees bloom several days earlier than healthy trees and tend to hold their leaves later into the fall.
Early in July, because of shortened internodes, infected peach trees appear more compact, leafier, and darker green than normal trees.

This diesease is widespread throughout North America.
The pathogen is spread by leafhoppers and high populations of leafhopper vectors contibute to heavy infections.