Vomitoxin levels in Ontario corn are low for second year in a row

Tuesday, October 15, 2013

by SUSAN MANN

For the second straight year an Ontario agriculture ministry survey has found incidents of corn ear mould and mycotoxins in grain samples to be minimal but growers should still check conditions in their own fields, says a provincial agriculture ministry spokesman.

A survey by the Ontario Ministry of Agriculture and Food field crops team shows that 84 per cent or 165 of the 197 samples taken in the survey done from Sept. 30 to Oct. 4 had a vomitoxin (DON) level of 0.5 parts per million, while 14 per cent or 27 samples had DON concentrations of 0.6 to 1.9 parts per million and two per cent or five samples were found with a DON level of two parts per million or greater.

Last year, four per cent of the samples were found with a DON level of two parts per million. That’s way lower than in the 2011 survey, when 23 per cent of the samples had a DON level of two parts per million or higher.

Greg Stewart, agriculture ministry corn specialist, described this year’s corn crop in general as “pretty clean.” Samples were taken from farms across southwestern, central and eastern Ontario and up to Georgian Bay. There wasn’t any one region that had high vomitoxin levels; fields having high levels were scattered throughout the province.

Farmers checking their own fields should look for damage on the end of the ears from birds or high Western Bean Cutworm feeding, he says. “Sometimes the damaged ear will have higher vomitoxin because the mould gets a bit of a chance to develop easier there.”

If the ear is damaged, growers should then check its tip for white or pink mould. Farmers should get that corn tested by a lab for vomitoxins. But “if you walk through a field and you can find absolutely no visual incidents of any mould on the ears then you probably don’t need to get it tested,” he notes.

The ministry’s field crops team has been doing the survey annually since 2006, a year with very high ear mould and vomitoxin levels, Stewart says.

A number of factors affect mold and vomitoxins levels in the corn crop, including weather and the type of hybrids. It’s hard to accurately predict if there will be a vomitoxin problem based on the weather alone, he notes. That’s partly why the field crops team does the survey early in the corn harvest season – to “give people a heads up,” he says. BF