2007/2008 SURVEY: SPRING ASSESSMENT 2008

Twenty five plants from each surveyed crop were assessed visually for symptoms of disease at stem extension.

• Phoma leaf spot was the most commonly found disease in the spring with 94.0% crops and 41.9% plants affected. The incidence within crops was slightly higher than last year when 36.3% plants were affected.
•  
• The national incidence of light leaf spot was markedly higher than last year. There were 62.0% crops and 22.8% plants affected, compared with 39.3% crops and 11.8% plants last year. This is the highest incidence of the disease recorded in the survey since 1995 when 75.4% crops and 48.8% plants were affected. Regional trends of the disease were consistent with previous years, with the highest incidence being in the North and the South West.
•  
• With an incidence of 21.0% crops and 1.2% plants affected, Alternaria leaf spot was found at higher levels than last year, when 9.5% crops and 0.4% plants were affected. The disease was recorded in all regions except the Midlands & West.
•  
• Downy mildew was found at similar levels to last year (15.0% crops affected compared with 15.9% crops affected), however, it does continue the downward trend which has been recorded since 2002. Downy mildew was found in all regions in the survey.
•  
• White leaf spot was only recorded in the East region (as last year), where 4.5% crops and 0.4% plants were affected. This is slightly higher than last year when 2.8% crops and 0.1% plants were affected.
•  
• Powdery mildew was not recorded on any crops in the survey. Ring ring spot and Botrytis were also not recorded in the survey. Ring spot was last recorded on the leaves in the spring in 2002, whilst Botrytis was last recorded on the leaves in the spring in 2003.

        Incidence of diseases on the leaf at stem extension - % crops affected



        Incidence of diseases on the leaf at stem extension - % plants affected



        Regional incidence of diseases on the leaf at stem extension - % crops affected


        Regional incidence of diseases on the leaf at stem extension - % plants affected