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Common Corn Rust

┬ęPurdue University, Plant and Pest Diagnostic Laboratory

Pathogen(s) causing disease:

Puccinia sorghi


Common to many countries of the world


Initial symptoms are chlorotic flecks on leaf surfaces. Flecks develop into oval to elongate reddish brown powdery pustules on upper and lower leaf surfaces. Reddish brown spores break through the leaf epidermis. Pustules become brownish-black as they mature. Usually not a serious disease in hybrids.


Disease develops best with cooler temperatures and relatively high humidity (95 per cent).


Resistant hybrids. Foliar fungicides can effectively control rust with timely application. Plant early or plant a shorter season hybrid.


Purdue University
Iowa State University
University of Nebraska
Bloomberg, Jim. Bayer CropScience Corn Disease Identification Guide PowerPoint. 2009.

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