Mycotoxin changes during hot and dry weather

Many people believe that this years’ hot, dry summer means lower risk of mycotoxins in cereal grains harvested in Europe between July and November. However, this is not always the case. Moulds are highly adaptable and different types of moulds grow best under different conditions and most produce spores, meaning they are present in dormant form and grow when conditions become favourable. Some prefer warm, dry weather, while others grow better in cool and wet conditions. Weather changes from one year to the next, change the species seen and this leads to a change in the type of mycotoxins produced. Mycotoxins are harmful substances that moulds typically produce when under stress, such as difficult weather conditions or when competing with other moulds/ microbes. Because different moulds produce different mycotoxins, knowing which moulds are present helps indicate which mycotoxins may form. Mycotoxins are often grouped into two main types: those developing during crop growth in the field (field mycotoxins), and those developing mainly during storage (storage mycotoxins). The 2 main storage mycotoxins are aflatoxins and ochratoxins, produced mainly by aspergillus and penicillium species of moulds. Most other mycotoxins are field mycotoxins, produced by a variety of moulds, with fusarium species most common.

1. Mycotoxins more likely under drier and hotter conditions

2. Mycotoxins more likely under wetter and cooler conditions