I found this condtion on my D'Anlou and Orcas pears.
These were sprayed with copper in late winter.
Should I apply copper now? These a young trees and have no fruit yet.
it could be....but usually the terminal shoots start to turn black...and die back from there. Spraying is most effective during dormancy. You can wait awhile and see what develops...or cut well behind the black leaves now. This disease can spread through pruner contact. very contagious...
I don't see any evidence on the shoots.
That's the reason I was wondering if it was fireblight.
That is the way it looked on my first leaf pear trees.
I removed and disposed of the leaves as soon as the symptoms appeared. Fireblight seems to have disappeared (none in second and third leaf) which is one advantage of living here---it is too hot for Fireblight ... and unfortunately too hot for most European pears.
I have no advice on spraying. I would remove and dispose of leaves as soon as you see the blackening. Young trees are a balance between the need for photosynthesizing leaves to keep them growing and keeping the bacterial amplification cycle down. Your local coop exchange or Master Gardner program should have advice on Fireblight.
This post was edited by Fascist_Nation on Sat, May 31, 14 at 17:48