• The incidence of black dot was again high, affecting a mean of 58.2% crops surveyed. The highest incidence (100% crops affected) was recorded in the South East, and the lowest (21.4% crops affected) in the North.

• Both silver scurf and common scab were recorded at a higher incidence than in the previous two years. Common scab was the most frequently encountered surface blemish, affecting 88.6% crops.

• Internal rust spot levels had increased since the previous year (40.5% crops affected in 2000 compared to 16.5% in 1999) and was also the only internal blemish to be encountered in samples from all regions surveyed. The highest incidence was recorded in the Midlands & West.

• The incidence of dry rot at 3.8% crops and 0.3% tubers affected was higher than in the previous year, and was recorded in the South East and South West & Wales only.

• Tuber blight was recorded in the South East and Northern regions only while gangrene was recorded only in crops from the East and North.

Fig. 1 Incidence of potato tuber surface disease - % crops affected

Fig. 2 Incidence of potato tuber internal disease - % crops affected

Fig. 3 Severity of potato tuber surface disease - % surface area affected

Fig. 4 Severity of potato tuber internal disease - % tubers affected

Fig. 5 Regional incidence of potato tuber surface disease - % crops affected

Fig. 6 Regional incidence of potato tuber internal disease - % crops affected