Head Smut

Encyclopedia Article

Description and Symptoms 

Head smut (Sporisorium holci-sorghi) is rarely observed in Iowa. Forming on the tassels and ears, galls are at first covered with a thin layer of tissue that breaks open to expose the black spore masses and threadlike remains of the vascular bundles. Leaf-like proliferations develop on the tassel and ears. Ears may be aborted and replaced with a proliferation of leafy tissue. Plants also may be severely dwarfed. Disease is most common in soils with nitrogen deficiencies. Most hybrids grown in the United States are highly tolerant. Rotation will reduce inoculum buildup, but some strains of the fungus can infect both corn and sorghum. Adequate nitrogen during the early growth stages reduces susceptibility.

Scouting

The best time to scout is R2 through R6. The head smut will be more severe when nitrogen is deficient and when fields are dry. Rarely occurs in the United States. 

Management 

Head smut will generally occur in low moisture enviornments and in temperatures between 70 and 82 degrees Fahrenheit when plants are seedlings.

Photo by Adam Sisson  

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