North Dakota State University’s early observations and tests of corn ear molds in North Dakota indicate that the majority of molds detected are not fungi species known to produce mycotoxins.

Mycotoxins can be a concern if they are in corn fed to livestock.

The NDSU Plant Diagnostic Laboratory has examined 27 ear samples from 10 North Dakota counties, and more than 95 percent of them showed a superficial black mold (Cladosporium), which is not associated with mycotoxin development.

The NDSU Extension Service is conducting a survey of corn ears from fields across the state, and many more samples have yet to be examined.

In addition to the formal corn survey, the Plant Diagnostic Laboratory has received 20 corn ear mold samples from private sources in three North Dakota counties and two other states. These samples also predominately had the black superficial, nontoxic mold present.

Eleven of these 20 privately submitted samples also have been analyzed by the NDSU Veterinary Toxicology Laboratory for the presence of mycotoxins. Mycotoxins were not detected in 10 of these samples, and the other sample had a low level (less than 1 part per million) of vomitoxin present. That is below the U.S. Food and Drug Administration’s advisory levels for livestock feeding.

Both NDSU labs will continue to examine ear molds for mold identification and conduct mycotoxin analysis, but preliminary results are encouraging because the majority of samples received so far have shown superficial black molds and other molds not associated with mycotoxins, says Marcia McMullen, an NDSU Extension plant pathologist.

Aflatoxin (and its causal fungus, Aspergillus) has not been found, and this mycotoxin is not expected because it is associated with stress conditions brought on by hot, dry conditions, a situation which did not occur in North Dakota in 2009.

“Corn Ear Molds: Basic Questions and Answers,” a new NDSU publication, is available online at http://www.ag.ndsu.edu/pubs/plantsci/rowcrops/pp1451.pdf.

NDSU Agriculture Communication