Some fungal species can grow on crops and foodstuffs and produce toxic chemicals. Of widely varying toxicity to humans and animals, these chemicals are called mycotoxins. To keep mycotoxin levels below set limits, it is important to follow best practice.
Which fungal species are associated with cereal mycotoxins?
In cereals, mycotoxins can result from fungi that either develop from field-borne infections (fusarium mycotoxins and ergot alkaloids) or in stored crops (ochratoxin A).
There are five fusarium species and two microdochium species that infect cereals and may cause ear or head blight. In the UK, the main mycotoxin-producing species are F. culmorum, F. graminearum and F. avenaceum. Microdochium species do not produce mycotoxins. Information on symptoms, life cycle, importance, risk factors and management of the pathogens that can cause ear or head blight can be found in the cereal disease encyclopaedia.
Legal and guidance limits
There are legal limits for fusarium mycotoxins deoxynivalenol (DON) and zearalenone (ZON) in wheat intended for human consumption and guidance limits for feed grain.
The owner (farmer, merchant or processor) is legally obliged to ensure grain is safe for human consumption. Depending on end use, processors may require a lower limit at intake than the legal limit for unprocessed cereals to ensure finished products conform to legal limits.
How to manage mycotoxin risks
- Follow best practice to minimise fusarium mycotoxins in cereals
- Assess risk pre-flowering and consider T3 fungicide (ear spray)
- Take accurate measurements of rainfall at flowering and pre-harvest (use the rainfall risk tool)
- Calculate final risk score at harvest and record on grain passport
- Check purchaser requirements to determine whether mycotoxin testing is required
The mycotoxin risk assessment
Mycotoxin rainfall risk tool
Rainfall-related mycotoxin risk assessment scores can now be calculated automatically with this tool.
Covering thousands of sites across England and Scotland, the map-based tool also shows how much rain has fallen during the critical winter wheat flowering and pre-harvest periods.
How to use the tool
- Enter the start and end dates in the boxes (typed in manually or selected from the pop-up calendar) for the defined rainfall period(s)
- At each site, a coloured circle reveals the risk score for the defined rainfall period
- Float the mouse cursor over a site to show the rainfall (mm) that fell during the defined period
- Enter the relevant score(s) onto the risk assessment
Note: Each Friday, results are quality controlled and anomalous data are removed – the latest ‘clean’ data can be viewed via the ‘QC’ tab.
The following resources will help you assess and manage mycotoxin risk. They will also help you to obtain composite and representative samples for testing for DON and ZON (where required by the end-user).
A robust foundation to instil confidence
An article from Crop Production Magazine
Agrochemical residues, mycotoxins and other major contaminants in cereals and co-products have been monitored independently since mid-1980s. Find out about our research that aims to help ensure the safety of the UK grain and its end-products.