2004/2005 SURVEY: SUMMER ASSESSMENT 2005
| Stems and pods of twenty-five plants from each surveyed crop were
assessed visually at pod ripening for symptoms of disease. |
| |
- Disease levels on the stems were generally higher than in the previous year.
- Alternaria and Botrytis were the only diseases on the pods to be recorded at higher incidence in
2004 compared to 2003. Incidence of dark pod spot rose slightly from 30.6% plants affected in 2003
to 35.2% in 2004, while Botrytis rose from 0.9% plants affected to 9.5%.
- As in previous years, incidence of Phoma canker was high with 93% crops affected. Canker was higher
in 2005 with 27% plants affected compared to 23% affected in 2004. Total phoma (including cankers and stem
lesions) in 2005 was recorded at 39% stems affected compared to 27% in 2004. Phoma pod spot was restricted
to the Eastern region and found at trace levels only.
- Levels of light leaf spot were higher than in recent years. The highest incidence on both stems and
pods was recorded in the Northern region where 29% plants showed pod symptoms and 31% plants showed stem
symptoms. Light leaf spot was not recorded on either stems or pods in the South East or South West regions.
- Incidence of dark pod spot (Alternaria spp.) was largely similar to levels recorded in 2004.
As in previous seasons the highest incidence of alternaria pod spot was recorded in the South West
region.
- Incidence of powdery mildew on the pods, at 6% pods affected, was very similar to incidence in
2004 when 6% plants were affected. Powdery mildew was recorded in all regions.
- Sclerotinia stem rot was recorded in all regions with a mean incidence of 17% crops and 2% stems
affected. The highest incidence was recorded in the South West (50% crops affected). Although higher
than in 2004, the proportion of crops affected nationally was lower than in 2002 and 2003.
- White leaf spot was not recorded on pods in any region, and downy mildew was not recorded on
either stems or pods from any region. Downy mildew on the stems has not been recorded in the
survey since 1991.
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Incidence of diseases on the pods - % plants affected
Incidence of diseases on the stems - % plants affected
Regional incidence of diseases on the pods - % plants affected
Regional incidence of diseases on the stems - % plants affected
