Diseased branches can be removed in late winter. Cuts should be made at least 4 inches below the diseased area. Infected branches which are pruned in the summer should be cut l0 to l2 inches below the point of visible infection. Since fire blight is so very contagious, the pruning shears needs to be cleaned between cuts. Streptomycin sulfate is an antibiotic for fire blight that is sold as Agrimycin, Agristrep, or Fire Blight Spray.
Bordeaux mixture is a less effective chemical control.
Good to intermediate resistant varieties of apples include Haralred, Sweet l6, Red Baron, and Dolgo. Excellent to good resistant ornamental crabapples include Adams, Centurion, Radiant, Red Splendor and Sargent. All rights reserved.