Symptoms:
Eyespot in corn can show up throughout the growing season. Circular lesions are roughly one-eighth to one-quarter of an inch in diameter. They look water soaked and appear in clusters. The leaf tissue in the center of each spot will die and turn a tan color with a brownish-purple ring around it. Every spot is also surrounded by a yellow halo that can be seen clearly when held up to the light.
Scouting: V6-R4
Eyespot overwinters in corn residue, and in wet conditions, it will produce spores that can be spread by wind and rain. This disease is more common in fields with a history of eyespot, corn following corn, reduced tillage and favors cool temperatures (roughly 70 degrees) with wet conditions.
Management:
- Plant hybrids resistant to eyespot in corn.
- Rotate crops.
- Tillage will break up the residue and allow the microbes within the soil to break down the residue faster.
- Use fungicides labeled for use against eyespot.