How to Manage Pests

Pests in Gardens and Landscapes

Rust—Tranzschelia discolor

Rust is usually seen first as bright yellow, angular spots on the upper sides of leaves. On the undersides of affected leaves, spores developing in the lesions give the spots a rusty red appearance. Severe foliar rust can cause a defoliation, which may also reduce yield. On fruit, rust appears as small, sunken dark spots. A small area around each spot remains greenish or yellow when the fruit begins to color, and the lesion often splits open by the time the fruit is ripe. If the surface of a lesion is peeled back, rust-colored, spongy spore masses can be seen.

Identification | Life cycle


Remove and destroy infected twigs, buds, blossoms, and fruit as soon as symptoms appear. Avoid overhead sprinklers or use a low angle to avoid wetting foliage. Treatment is not usually necessary in home orchards. If infections are severe, a fungicide application in the spring can reduce or prevent fruit infections.

Rust symptomsSymptoms of peach rust

Statewide IPM Program, Agriculture and Natural Resources, University of California
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