UC IPM Online UC ANR home page UC IPM home page

UC IPM Home

SKIP navigation

 

How to Manage Pests

UC Pest Management Guidelines


Rust pustules on corn leaves.

Corn

Common Rust

Pathogen: Puccinia sorghi

(Reviewed 1/06, updated 1/06)

In this Guideline:


SYMPTOMS AND SIGNS

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.

COMMENTS ON THE DISEASE

Mild temperatures (60° to 73°F) and high relative humidity (near 100%) favor rust development. Initial inoculum is probably windblown spores from subtropical and tropical areas where the pathogen persists on living corn plants. The alternate host of the fungus, Oxalis species, probably does not play an important role in the disease cycle in California.

MANAGEMENT
Cultural Control

Use resistant hybrids to prevent common rust.Generally, fungicides are not required under California conditions.

PUBLICATION

[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Corn
UC ANR Publication 3443
Diseases
R. M. Davis, Plant Pathology, UC Davis

Top of page


Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2014 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   /PMG/r113100811.html revised: April 25, 2014. Contact webmaster.