Diplodia ear rot

The fungus appears as a conspicuous white mycelial growth over the husk and kernels. Small, black structures (pycnidia) can often be seen on kernels or the cob. The disease is most common in continuous corn. Infection takes place when wet weather occurs during silking. Crop rotation and fall tillage of corn residue reduce the disease levels.

Taken from Corn Production Handbook, KSU Extension