Area of impact: Leaves
Description: Small, round, watery lesions develop into tan "eyespots," surrounded by a brown to purple ring and yellow halo. Eyespots often join together to form patches and will be mainly found on the upper leaf surface.
Pathogen involved: Kabatiella zeae (a fungus)
Timing/Conditions: Lesions can occur anytime between corn silking and maturity. Cool, humid weather favors the disease.
Contributing factors: Continuous corn and conservation tillage. Overwinters in corn residue.
Management practices: Use resistant hybrids and crop rotation, and reduce corn residue with tillage.