Agriculture: Pear Pest Management Guidelines

Treatment Timing for Key Diseases

Note: Not all indicated timings may be necessary for disease control.

Disease Fall Delayed dormant Green tip/
White bud
Pink bud/
Full bloom
Petal fall/
Cover sprays
Fire blight 0 1 2 3 34
Powdery mildew3 0 0 1 3 3
Scab1 22 22 3 3 3
Rating: 3 = most effective, 2 = moderately effective, 1= least effective, and 0 = ineffective
1 Protection of early tissue is important. Additional applications should be made according to infection periods as determined by the Mills table.
2 Disruption of pseudothecial (ascostroma) development (fall) and inactivation of overwintering twig lesions (delayed dormant); effects of these treatments on disease control is uncertain.
3 Early applications are most effective; additional applications are made if mildew continues.
4 Start management program at the beginning of bloom and continue through bloom including "rat-tail" bloom throughout spring. Several models are available for forecasting infection periods and treatment timing. Models include: Maryblyt, Cougar Blight, etc.

Acknowledgment: Adaskaveg et al., 2022. Fungicides, Bactericides, Biocontrols, and Natural Products for Deciduous Tree Fruit and Nut, Citrus, Strawberry, and Vine Crops in California. (PDF)

Text Updated: 03/22