Penicillium ear rot of corn
Penicillium ear rot is caused by multiple Penicillium spp. It is characterized by green or blue-green powdery mold growing between kernels, usually at the tip of the ear. Infected kernels can appear bleached or streaked.
This rot occurs primarily on ears damaged mechanically or by insects, and it is more common in non-Bt corn because of the greater potential for insect damage.
Penicillium ear rot can be a problem in stored grain if moisture in the bin is high, causing a condition known as "blue-eye." Grain should be dried appropriately before storage and if blue-eye is found in storage, test grain for mycotoxins. Penicillium ear rot associated with hail injury to the ear. Image: A. Robertson
Penicillium ear rot at the tip of the ear. Image: T. Allen