We planted a Comice pear tree and a Bartlet so we would have cross pollination. It is their third year and we were happy to see blooms and tiny pears. But then we started noticing some of the leaves turning black.
I looked up "fire blight" and found the best way to control it is to prune the branches off that show it. Well, our lovely, well shaped pear trees look really sad now. I'm not sure we'll be able to get any pears off of them...ever.