MAPPING OF FHB PATHOGENS
Distribution of F. culmorum and F. graminearum
In 2008, levels of F. graminearum were equivalent to those seen in 2008; 26% of the
fields sampled had infections confirmed. F. culmorum was only isolated from
3% of samples. Mapping of the geographical distributions of both species showed the
isolations occurred in areas similar to 2007, although the frequency of isolation was
reduced in the South West, in particular around Dorset and Wiltshire.
| F. culmorum and F. graminearum distribution 2008 (left) and 2007 (right) | ||
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Between 1998 and 2008, significant changes in the frequency and distribution of both F. culmorum and F. graminearum have occurred. Overall, there has been a downward trend in the prevalence of F. culmorum. Conversely, F. graminearum has increased in occurrence, with isolations outnumbering those of F. culmorum for the first time in 2002. The trend in predominance has continued between 2003 and 2008. Isolations of F. graminearum between 1998 and 2002 were primarily from crops in the south west and south east of England and in Norfolk. Between 2003 and 2008 occurrence of F. graminearum has spread northwards, particularly into Lincolnshire. In the future, increased levels of F. graminearum may lead to greater levels of mycotoxin in grain because this species is generally regarded as more aggressive than F. culmorum both in terms of effects on yield and in the potential to produce mycotoxins.
F. graminearum 1998 - 2008
F. culmorum 1998 - 2008
