Corn Diseases in Ohio

Gray leaf spot

• Symptoms
  • leaf lesions are pale brown or gray, parallel-sided and 1/16 to 1/4 x 1/4 to 2 in.
  • usually occurring late in the season
• Environment
  • warm, humid weather
  • July through August.
• Survival
  • fungus survives on crop residues and on barnyard grass and johnson grass.
  • spread by wind and splashing rain.
• Management
  • resistant hybrids
  • clean plowdown of crop residues.
  • crop rotation.
  • fungicide application on susceptible hybrids.
• Scouting
• Gray leaf spot article