Cochliobolus heterostrophu (also known as Bipolaris maydis / ), Disease development is promoted by prolonged wetness on foliage, extended dew, Relative Humidity (97-100%) and relatively warm temperatures (24-35° C).
looks like southern corn leaf blight as the Professor Houda Kawas indicates
Moist chamber with sporulation can give confirmation along with a PCR Blast analysis.
The commercial product tilt would be able to control an epidemic. Particularly when made at critical periods based on environmental conditions and plant stages.
South Corn Leaf Blight is usually controlled by genetic resistance.