See:
Cherry (Prunus spp.) - Brown Rot Blossom Blight and Fruit Rot
Pear (Pyrus spp.) - Fire Blight
Note The early symptoms of brown rot blossom blight on quince could be mistaken for fire blight.
Closeup on flowers that have died back but not fallen off. Sporulation of the fungus can be seen as a gray cast to the dead flower parts.
Jay W, Pscheidt, 2008.
Blossom blight occurs during bloom when temperatures during rainfall are over 50F.
Jay W. Pscheidt, 2012
See:
Cherry (Prunus spp.) - Brown Rot Blossom Blight and Fruit Rot
Pear (Pyrus spp.) - Fire Blight
Note The early symptoms of brown rot blossom blight on quince could be mistaken for fire blight.