Bacterial blossom blast—Pseudomonas syringae
Bacterial blossom blast of pome fruits occurs mostly in areas where frost is likely to occur during
bloom. Frost or freezing temperatures and free moisture are required. In cold, wet spring weather, blossoms
brown, shrivel, and usually cling to the tree. Leaves may also develop brown or black spots that later
drop out. Sunken spots may develop on young fruit.
Blossom blast is difficult to control. Procedures applied for frost
protection may prevent infection.
blossoms and shoots killed by blast