Mycotoxins/Ear Rot Diseases of Corn

Mycotoxins can become an issue for livestock producers and corn growers when environmental conditions during the growing season are conducive to mold growth.  During wet and cool weather, delayed planting, or crop development to the point where kernel moisture is high late into the fall, corn ear molds can be common.
Molds, depending on type, can grow under a wide range of environments.  The general conditions needed for Fusarium field molds are high humidity, oxygen, and temperatures that fluctuate between hot days and cool nights.  These can cause a wide range of diseases in grass and cereal crops.  

In corn, Fusarium causes Gibberella and Fusarium stalk rot, Fusarium crown rot, Fusarium kernel rot, and Gibberella ear rot.

Gibberella ear rot is important not only because of the potential yield and quality losses but because Gibberella zeae and Fusarium graminearum produce two very important mycotoxins, deoxynivalenol (vomitoxin or DON) and zearalenone. Fusarium infection produces a white to pink or salmon-colored mold and the fungus produces a toxin called fumonisin.

Corn growers can produce high yields when planting is done early, normal heat units are accrued, and there isn't an early fall frost.  However, when all or some of these conditions don't happen, it sets the corn up for a longer dry down period under environmental conditions that are potentially more conducive to stalk and ear mold development. It is during the fall that conditions are optimum for Fusarium ear mold and mycotoxin development (alternating hot-cold temperatures between 45 and 75 degrees Fahrenheit).

To learn more about mycotoxins, sign up for the webinar, Trends in Mycotoxins/Ear Rot Diseases of Corn for 2010.