Answer: I'm concerned. Fire blight attacks bradford pear trees. The symptoms: leaves wilt suddenly, turn dark brown to black, shrivel, and die, but usually remain attached to the plant. If this sounds like what's happening to your plant, prune off the obviously affected branches and stems, 6 to 8 inches below the affected tissue. Be sure to sterilize your pruners between each cut so you don't transfer pathogens. There's no chemical control for homeowners so pruning out infected plant parts is your best control option.
The only other thing that might cause the symptoms you describe is wind burn. If you've had some windy weather, the new leaves may be dessicated from the wind. In this case, you don't need to do anything. The leaves will fall and, because it's early in the season, new leaves will grow in their places. For your tree's sake, I hope the wilting is from wind damage.
Best wishes with your tree~
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