Each spring my pear trees leaves turn brown and die. It starts with one branch and then continues to spread throughout the tree. All I've been able to find regarding this is that the foliage is too lush and to prune the dying branches and get them away from the tree. I've tried pruning to allow better air flow through the branches but it is still very lush despite my efforts and I don't know what else I can do to eradicate this problem. Any suggestions? Also, my sour cherry trees appear to be dying. Lost 1 last year and the top of another hasn't leafed out this year and appears dead. Should it be pruned off along with dead branches?
Pulaski County Kentucky
I suspect that the pear tree is suffering from file blight, although it is difficult to diagnose disease with only a description of the symptoms. Here is a link to a publication from UK Plant Pathology that gives more information on fire blight: http://plantpathology.ca.uky.edu/files/ppfs-fr-t-12.pdf.
Tart (sour) cherries also suffer from bacterial diseases but not usually fire blight. More often they exhibit problems with cankers on their stems which become gummy over time and ooze resinous material. Many cherries and related species succumb to these diseases and when most of the tree is infected is time to replace it with a new tree. Here is a publication on stone fruits which includes cherries: http://plantpathology.ca.uky.edu/files/ppfs-fr-t-08.pdf
For an accurate diagnosis you should take samples of the diseased and healthy areas of the trees to the Pulaski County Extension Office. The horticulture agent there should be able to diagnose the problem or will send the samples to one of the UK plant diagnostic labs for analysis.
Rick: Thanks for your timely response to my questions! I'm sure the fire blight is the issue with my pear tree. I'll try to find a spray for the bacteria. I'll have to study the cherry trees closer to see if I can verify the problem.