Fusarium and microdochium in cereals

This complex of diseases causes a variety of symptoms on wheat, barley and oats, including the production of ear blights and mycotoxins in grain. Learn about the pathogens and access information on how to manage them.

Infection by fusarium and microdochium species in cereals can lead to various symptoms, such as poor establishment and ear blights.

Although infection is associated with lower yields, the production of mycotoxins in the grain by some species is the biggest concern.

Fusarium graminearum and Microdochium nivale cause the most significant seedling losses in UK wheat. However, surviving plants can tiller to compensate for these losses (to varying degrees).

F. graminearum is more common in maize-producing areas, whereas M. nivale is more generally distributed.

In the UK, severe foot rotting in wheat is very rare, because badly infected seed is avoided and seed treatments are effective. Generally, losses are very small.

High levels of ear blight can occur, especially when conditions are conducive (e.g. wet) during flowering, but yield losses are rarely serious.

Although the fusarium mycotoxins DON and ZON are frequently detected in wheat, and usually at higher levels than in barley and oats, monitoring (funded by AHDB and others) shows that average concentrations are usually below the legal limits.

Limits are most frequently exceeded in wet harvest years.

Seedling blight in barley due to fusarium species is rare, but may occur under high infection pressures, such as when infected seed is sown into cold seedbeds. In general, losses are not as high as in wheat.

Early sown spring barley is at greater risk of M. nivale seedling blight infection.

Ear blight and mycotoxin risk is also lower in barley than in wheat.

As per wheat, barley crops are at increased risk when they are commonly grown in rotation with maize with minimum tillage.

DON, ZON, T-2 and HT-2 levels in barley have been routinely low with legal limits rarely exceeded.

In general, oats are more resistant to fusarium infection than wheat and barley.

Visual symptoms are also far less common, although bleaching of spikelets and premature plant death can sometimes occur.

F. langsethiae is main species that infects oats, which also produces T-2 and HT-2 mycotoxins.

There is good evidence that most mycotoxins are removed during dehulling (at least 90%).

Food Standards Agency (FSA) surveys of fusarium mycotoxins in retail oat products show that exposure to these toxins from oat products in the UK diet is very low.

There is little correlation between fusarium-damaged grains and mycotoxin occurrence. Therefore, the presence of ear blight symptoms is not a good indicator of mycotoxin risk.

The risk of fusarium diseases can be minimised throughout the season: from rotation planning, to deciding which field to harvest first.

Although the risk assessment tool was developed for use in wheat, it can also indicate risk in barley.

Our fungicide performance work provides high-quality, independent information on the relative efficacy of fungicides against key diseases in wheat, barley and oilseed rape.

It includes dose-response curves for fusarium head blight control in winter wheat.

The fungicide performance web pages also provide information on seed treatments with efficacy against seedling blights.