|This one may be a lost cause.|
It sounds as though your pear tree has fire blight, a bacterial disease that can infect trees during bloom or during the growing season. It's more severe during warm, wet weather. Symptoms include brown or black leaves that cling on the tree. The tips of branches often curl into a shepherd's crook. In severe cases, the entire tree may be killed...I really thought it was a late frost that was causing some leaves on a pear tree or three to blacken and shrivel. But after a quick trip through the orchard this morning and a little research, I'm pretty sure the truth is far worse. The rainy weather and my lack of pruning last winter has created the perfect environment for an outbreak of fire blight, a bacteria that is all but fatal to whatever fruit trees it touches.
My trees have an odd case, as other than the one pictured, which is brown top to bottom, every tree seems to have but a bad branch here and another there. So it's all over the place, but I probably won't lose too many whole trees. I'm gonna have a hell of a burn party this winter, however.
Unfortunately, there's nothing I can do about it right now - lopping trees that are in the midst of their spring growth spurt is the best way to spread it around. Instead, later this summer and over winter I'll need to:
1) Remove and burn all damaged branches in big, big chunks.
2) Wherever cankers (bark broken by the infection) appear, scrape it down to bare wood or take the branch out.
3) Thin the orchard pretty severely. When I planted these pears, I had no idea how big and full they would really grow. A twenty-foot spread is just a number in a book when you're planting saplings. Now it's time to do the serious work of keeping them away from each other. I'm gonna need a bigger ladder.
I'm not sure how the pear harvest is going to be this year - the trees don't seem to be setting fruit in anywhere near the quantities of the past 2 years*. But that's why we strive to learn these lessons while we can still buy pears in #10 cans at WalMart.
* I am thankful that the peach harvest looks to be off the charts. Plus we are down to the last three quarts of 2013 pears, meaning we have not started to eat last year's harvest yet.