How to Manage Pests

Pests in Gardens and Landscapes

Common rust on corn—Puccinia sorghi

Common rust causes pustules that may appear on any aboveground part of the corn plant but they are most abundant on leaves. The pustules, which may erupt and become powdery, occur nearly simultaneously on both leaf surfaces. They are golden brown to cinnamon brown, becoming black as the spores mature.


Common rust is favored by cool temperatures and high humidity or overhead sprinklers. Use furrow or drip irrigation. Generally, fungicides are not required. Some resistant varieties may be available.

Rust pustules on corn leaves
Rust pustules on corn leaves

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