Treatment Timing for Key Diseases

Not all indicated timings may be necessary for disease control.

Disease	Dormant	Bloom		3 to 6 weeks postbloom	Preharvest1
		20 to 40%	80 to 100%		3 weeks	1 week
brown rot	0	2	3	1	2	3
leaf curl3	3	1	0	0	0	0
powdery mildew	0/ND	2	3	32	0	0
rust	14	0	0	3	2	0
scab	0	1	2	3	0	0
shot hole5	3	1	1	2	0	0

Rating: 3 = most effective, 2 = moderately effective, 1 = least effective, 0 = ineffective, and ND=No data

1	Timing not exact; weather conditions determine need for treatment.
2	Apply until pit hardening
3	Treatment should be made before bud break and preferably before bud swell.
4	Dormant treatment with liquid lime sulfur.
5	Fall application before winter rains begin is the most important; additional spring sprays are seldom required but may be needed to protect the fruit if heavy, persistent spring rains occur.

Acknowledgment: Adaskaveg et al., 2025. Fungicides, Bactericides, Biocontrols, and Natural Products for Deciduous Tree Fruit and Nut, Citrus, Strawberry, and Vine Crops in California.