MAPPING OF FHB PATHOGENS
Distribution of F. culmorum and F. graminearum
In 2007, levels of F. graminearum were greater than in recent years;
26% of the fields sampled had infections confirmed. F. culmorum was isolated from 13% of samples
which is also more than in recent years. Mapping of the geographical distributions of both species
showed the majority of the isolations occurred south of a line stretching from Lincolnshire down
to Gloucestershire. The distribution of both F. culmorum and F. graminearum in 2007 reflected
the areas where the heaviest rainfall was seen during flowering of the winter wheat crop.
F. culmorum and F. graminearum 2007
Between 1998 and 2007, 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 2007. 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 2007 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. culmorum 1998 - 2007
F. graminearum 1998 - 2007
Distribution of other species 2007
