Ochratoxin A (OTA) is a potent mycotoxin that can form on stored grain in high moisture conditions. OTA is produced by Penicillium verrucosum, a naturally-occurring soil fungus; but, unlike deoxynivalenol (also known as DON or vomitoxin) which is formed in the field, OTA forms exclusively in storage.

The most common source of Penicillium verrucosum spores is from soil particles, last year’s stored grain, grain handling equipment, and residues remaining in the bin. Penicillium can grow in small pockets of wet grain, or when water comes in contact with grain – even in bins that are generally well managed and properly aerated.

To mitigate the risk of OTA forming in your grain, adhere to the following Keep it Clean! safe storage protocols:

  • Keep bins and grain handling equipment clean, thoroughly cleaning dust and debris between grain lots.
  • Ensure crops are harvested or dried to a safe level for storage.
  • Cool the grain quickly to well below 10°C and keep it cool for as long as possible to minimize condensation in the bin. Even fine droplets of condensate can allow the fungus to grow.

Click here for further information on OTA and how it forms, along with visual examples of OTA formation at critical points of handling and storage.