Southern corn rust
Area of impact: Leaves
Description: Round, light brown to orange spots scattered mainly on the upper leaf surface but may also appear on husks stalks, lower leaf surface and ear shanks.
Pathogen involved: Puccinia polysora (a fungus)
Timing/Conditions: Usually occurs just after silking during warm humid weather.
Contributing factors: Overwinters in the southern U.S. and Mexico and spores are blown north to the Corn Belt in early summer.
Management practices: Plant resistant hybrids and apply fungicide as needed.