Tips to ID Ear Molds

Something went wrong. Please try again later...

All corn ear molds are not created equal. Some produce dangerous mycotoxins; others don't. Growers should identify and manage ear molds before harvest.

The presence of visible molds is only an indicator. Growers must identify and quantify ear molds to determine potential negative impacts. Here are some tips:

  • If 10 percent of the ears have mold on more than 25 percent of the ear, send a sample for identification.
  • If molds are present, you may need to contact the crop insurance agent - especially if the degree of infection may affect grain quality.
  • If the mold is identified as Aspergillus, Fusarium, Gibberella or Penicillium strains - and the levels are greater than 10,000 cfu/gram (colony forming units per gram) - the grower should schedule a mycotoxin screening.

Once a mycotoxin threat is detected, you need to consider harvesting and storage strategies.

A good practice is to harvest and dry moldy grain in a "continuous-flow" dryer to a moisture level of 14 percent. Cool the grain to ambient air temperature as quickly as possible.

The cool-down process should begin as soon as grain goes into storage. Ultimately, the grain should cool to 30 to 35 degrees for safe storage.

Once cooled down in storage, monitor grain regularly - at least weekly until it's sold or used.

A crop containing mycotoxins may be fine for some markets; however, you must be careful about selling it to someone who'll use it as livestock feed. In many cases, contaminated grain can be mixed with "clean" grain to bring mycotoxin concentrations down to safe levels. Check with local university extension sources for thresholds on feeding various species.