Evaluate new chemical controls to be incorporated into Integrated Pest Management of fire blight
There are many copper formulations registered for fire blight control at various timings in NYS. Copper is historically used to reduce the amount of bacteria available for blossom infection by intercepting and killing some of the bacteria oozing from the overwintering cankers. But copper also has a reputation for russetting fruit finish if applied too close to bloom time. Timing the copper application closer to dormant so there is little residue available when fruitlets are susceptible to fruit finish damage can minimize fruit russet. But this may be too early since fire blight cankers do not become active and produce bacterial ooze until closer to bloom. Cuprofix Disperss is a recently registered material in NYS with fire blight control on the label between silver tip and green tip at 10-20 lb./acre. This study was conducted to evaluate fire blight control if 2 applications of Cuprofix Disperss between silver tip and green tip provided improved control and improved fruit finish compared to other grower practices. Since blossom blight is the primary mode of fire blight epidemics and not completely controlled by copper treatments applied prebloom, streptomycin continues to be a critical control method for minimizing fire blight infections in orchards.
New York State IPM Program
Agricultural IPM; Apples; Fruits; Tree Fruit