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Apple Disease Control Toolbox - Fungicide Timing

Timing of a fungicide application in relation to disease development is important for achieving the best results.
Updated:
March 9, 2020

Timing of Treatment Based on Apple Disease to be Controlled

Please refer to product labels and the Penn State Extension Tree Fruit Production Guide for details on chemical use at each timing.

Alternaria leaf blotchApple scabBitter rotBlack rotCalyx-end rotFlyspeckPowdery mildewRustsSooty blotchWhite rot
½-inch green — ++ — — — — — — — —
Prepink — ++ — — — — ++ — — —
Pink — ++ — — — — ++ ++ — —
Bloom period — ++ ++ ++ + — ++ ++ — ++
Petal fall ++ ++ ++ ++ + — ++ ++ — ++
First cover spray ++ ++ ++ ++ + — ++ + — ++
Second cover spray ++ ++ ++ ++ — + ++ — + ++
Third cover spray + + ++ ++ — + — — + ++
Fourth cover spray + + ++ ++ — ++ — — ++ ++
Fifth cover spray + + ++ ++ — ++ — — ++ ++
Sixth cover spray + + ++ ++ — ++ — — ++ ++
Seventh cover spray + + ++ ++ — ++ — — ++ ++

+ presence of disease and possible control
++ ideal timing of material for disease control
-- control generally is not needed at that time

Associate Research Professor, Tree Fruit Pathology
Expertise
  • Apple and pear diseases
  • Peach, cherry, other stone fruit diseases
  • Tree fruit disease management
More By Kari A. Peter, Ph.D.