Identifying and Managing Ear Mold

Identifying and Managing Ear Mold

The prevalence of ear rots and ear molds in corn is highly dependent on weather conditions and varies from year to year. It is important to identify the specific type of ear infection in your corn. This Tech Update provides photo reference and information to help you make positive identification.

Pioneer is an industry leader in developing and characterizing hybrids that deliver protection against these common ear rots and molds. Pioneer has one of the industry’s most aggressive global screening programs, identifying disease hot spots and exposing hybrids to these extreme conditions. From this screening process, Pioneer agronomists and a staff of plant pathologists then assign scores to hybrids for key diseases, helping determine which ones are best suited for specific environments. Through this intensive work, Pioneer is able to deliver products that can be confidently matched with the needs of nearly every disease environment to protect yield, improve the quality of grain and deliver exceptional test weight.

In addition to disease screening efforts, Pioneer also offers leading in-plant insect protection for stalks and ears. Insect feeding on ears provides entry sites for ear rot and ear mold organisms which, in turn, can lead to poor grain quality, economic loss and grain storage issues. Pioneer® brand hybrids with Herculex I and Herculex XTRA in-plant technologies help control ear molds and rots by reducing ear feeding by corn borers, western bean cutworms and fall armyworms.

Talk to your local Pioneer sales professional regarding hybrids that have been locally characterized to best meet the needs of each of your fields.

Diplodia Ear Mold

Initially appears at the base of the ear and works its way to the tip. Damage from insects such as WBCW and ECB often provides an entry point for infection. Diplodia is favored by wet weather during grain fill and is usually more severe in hybrids with upright ears and tight husks.

Photo: Diplodia ear mold example. Photo: Diplodia ear mold example.
Diplodia ear mold

Gibberella Ear Mold

Overwinters in corn residue, infecting ears through the silk. Gibberella ear rot is a result of the same fungus that causes stalk rot. It thrives in cool wet weather after silking and is a red- or pink-colored mold that usually starts at the tip of the ear. Gibberella mold is favored by a long, tight husk cover.

Photo: Gibberella ear mold example.
Gibberella ear mold

Aspergillus Ear Mold

Most severe in drought conditions (especially during pollination and grain fill), extreme heat or where insects have damaged ears.

Photo: Aspergillus ear mold example.
Aspergillus ear mold

Penicillium Ear Mold

Powdery green or blue-green mold that develops, usually at the ear tip, as a result of mechanical or insect damage.

Photo: Penicillium ear mold example.
Penicillium ear mold

Fusarium Ear Mold

Usually infects individual kernels or groups of kernels scattered over the ear. Fusarium is most severe when hot, dry conditions occur during and after flowering. It produces a pinkish-white fungal growth on infected kernels, or sometimes a “starburst” pattern with white streaks radiating from where silks were attached.

Photo: Fusarium ear mold example.
Fusarium ear mold


Herculex® I HX1 – Contains the Herculex® I Insect Protection gene which provides protection against European corn borer, southwestern corn borer, black cutworm, fall armyworm, western bean cutworm, lesser corn stalk borer, southern corn stalk borer, and sugarcane borer; and suppresses corn earworm.
Herculex® I Insect Protection technology by Dow AgroSciences and Pioneer Hi-Bred. Herculex® and the HX logo are registered trademarks of Dow AgroSciences LLC.
Herculex® XTRA Herculex® I Herculex® RW
HXX – Herculex® XTRA contains both the Herculex I and Herculex RW genes.
Herculex® XTRA Insect Protection technology by Dow AgroSciences and Pioneer Hi-Bred. Herculex® and the HX logo are registered trademarks of Dow AgroSciences LLC.