Doesn't sound like mites.
any chance of pictures?

Picture attached

Here is a link that might be useful: Kieffer pear leaves

Bump. My pear has leaves that look just like this. Ever since early Spring. I thought it might be from mites or too much water, but there appeared to be a canker...or weird concave spot on the main leader. I cut the new tree pretty much in half fearing fire blight. It was only about 3 feet to start with. Now it's half that and showing the same blackening around the edges. I did dig up the tree and place it in a large container to isolate it and see if watering might have been the issue. I don't think it's due to water. What could the blackening edges be caused by? Thanks!

OK, I think everything is fireblight, and I'm going to be consistent here.

Good luck,

M

I recently planted various southern pears that were way too big, way too late, in way too much heat, also in lousy sandy soil among oaks and pines and a handful show a moderate amount of leaf blackening. But I do not (yet) have noticable wilting of the blackened leaves and they are notably not at the twig tips. Thus it doesn't look like fire blight. Some pear leaves turn black no matter what has killed them. I'm wondering if it isn't just general stress from transplanting and maybe some recent drought stress that I did not notice. Pears are tough: these were transplanted bareroot at 8-10 feet tall and leafed out, but they kept nearly all their roots (I easily shook the 25-gallons of loose potting soil off of them) and were bare-root, in the shade, for only a minute or two.

I purchased a 4 X 1 pear from Bay Laurel Nursery(the root butchering place) this past Spring. Keifer is one of the 4 varieites on it. All four varieties on it are touted as 'Fireblight Resistant'. The Keifer is the hardest hit variety on it that seems to fit your described problem. Some edge drying on all of the variety's leaves, but thankfully just on the edges only. My hunch is that it is a sufficient water uptake and dispersion problem from lack of feeder roots. Maybe an inability for the tree to not get enuff moisture into it during the heat, even though is getting ample supplemental watering. Maybe young grafts might also have something to do with this? I have given my tree some root stimulator in the hopes of helping it out some.

It's not the leaf that makes me think fire blight but the black in the stem above it, and at the axils of other stems.

By the way, I took the liberty of glancing at the other photographs on that page, and they were very lovely. Very nice work.

Thanks, M