A common problem observed by grain handlers is the appearance of corn with germ discoloration. Discoloration of the germ indicates kernel death.
Blue eye is caused by the production of blue-green fungal spores on the germ in storage.
Aspergillus glaucus or species of Penicillium . The presence of blue eye indicates that the grain has been improperly stored. Identifying the fungus responsible for the blue eye is of value because it may help determine what may have gone wrong in storage. Infection of kernels by this fungus can occur in the field if ears are damaged by insects, but blue eye usually does not develop until after harvest. Many times the fungus grows and causes blue eye in corn that is stored on the cob in cribs.