Leaves on Dwarf Pear Curling and Turning Black

Read stretcher.com and search under fruit trees for treating your tree in the fall. Same excellent treatment tips as given by Mrs Christmas, but suggestions for dormant sprays as well.

It sounds like peach tree leaf curl. It is caused by an insect pest. There is nothing to be done this year but in the Autumn, after the pests have gone back down into the soil you need to put a grease band around the trunk of the tree about 12'18 inches from the ground. Then when they try to crawl back up in the spring they will get stuck and trapped by the grease.
Grease is used becase it doesn't wash off. in the winter rain. It also helps if you clear up fallen leaves and loosen the top of the soil around the tree, this exposes the bugs the birds can get them then.