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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:

January 22, 2026

An orchard in front of a hill.

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 blotch	Apple scab	Bitter rot	Black rot	Calyx-end rot	Flyspeck	Powdery mildew	Rusts	Sooty blotch	White 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	+	+	++	++	—	++	—	—	++	++