With the exception of Terrington in Norfolk, which was sown in January, all of the Live Monitoring sites had reached or passed GS39 (flag leaves emerged) when assessed this week.
Only two Live Monitoring locations (Cirencester, Gloucestershire and Telford, Shropshire) reported visible Septoria on the top three fully-emerged leaf layers. However, with a medium or high weather risk recorded at a high proportion of weather stations over two or more weeks in May, Septoria pressure has been increasing although symptoms may not yet be evident. The overall disease risk is moderate for susceptible varieties, but moderate to high towards the South West.
Yellow rust was found at one more location, Telford, with a small increase in incidence or severity at the previously affected sites (Caythorpe in Lincolnshire, Terrington in Norfolk and Cirencester). Oakley and Solstice continue to be the main varieties affected. Another week of favourable weather means that the disease risk has stayed moderate to high for susceptible varieties, but moderate to low towards the South East.
Not surprisingly brown rust has remained absent from all locations and varieties. The arrival of warmer weather in early June means that the risk to the many varieties that are now susceptible has begun to increase, but from a very low starting point.
The Telford and Caythorpe Live Monitoring sites remain the hotspots for mildew infection. Symptoms have also developed at Cirencester, with just a trace found at Morley in Norfolk. High risk weather conditions were recorded at some locations last week, but the disease risk is still highest towards the North West.