Field Crop Diseases
Information and Management for Illinois
Go to the Department of Crop Sciences home page.
University of Illinois
College of Agricultural, Consumer and Environmental Sciences
Corn Diseases Soybean Diseases Wheat Diseases Sorghum Diseases Alfalfa Diseases

Northern Corn Leaf Blight



  • Lesions are gray to green in color, cigar shaped, and (3 - 15 cm) long
  • Lesions may contain prominent, dark areas of sporulation as they mature
  • The length or size of lesions may vary with their different reactions to resistant genes within corn hybrids

Pathogen Involved:

  • Setosphaeria turcica (a fungus)
  • Overwinters on corn leaf debris.
  • Races of this pathogen are grouped according to their virulence to resistant Ht genes
  • Race 1 is not considered important, because of use of the Ht1 gene for resistance in most commercial corn hybrids
  • Race 2 may infect commercial corn hybrids that only have the Ht1 gene for resistance .

Time of Occurrence:

  • Occur at silking or after silking of corn
  • Most prevalent during warm and prolonged periods of moisture during the growing season
  • Significant grain losses can result if this disease begins before silking

Conditions Favoring Disease:

  • Moderate temperatures of 66 - 80 F
  • Long periods of dew

Disease Management:

  • Use resistant hybrids
  • Fungicides may be warranted during the early stages of this disease for seed corn

 Back to Corn Diseases

[Field Crop Diseases]
[Integrated Pest Management]

[Department of Crop Sciences]
[University of Illinois Extension]

[College of ACES]
© 2001
University of Illinois