How to Manage Pests

Seasonal development and life cycle—Peach rust

On peaches, the rust fungus survives the winter in twig lesions. Spores produced in these lesions during wet weather in the spring infect leaves and the disease continues to spread to other foliage and fruit during periods of wet weather. Foliage infections are dormant during the summer unless rain or irrigation creates humid conditions. Leaf lesions serve as an inoculum source for fruit and twig infections. Peach fruit become susceptible to rust infection when they are nearly full sized, and rust symptoms appear in late May or early June. New twig growth of peaches is infected during damp weather in summer and fall. Lesions on twigs may be apparent, but spores are not produced in these lesions until the following spring.

Rust overwinters in twig lesions