CropMonitor: Yellow and brown rust predictions for the week beginning 20 May
At the Live Monitoring sites, crop growth stages varied from GS30 to GS33. Some more advanced crops have been reported on farm, but many are still very backward for the middle of May, with progress slow and signs of compaction or other stresses widespread.
Septoria tritici
Visible Septoria levels vary from negligible to moderate, depending on location, but in general there are few symptoms on the upper emerged leaf layers. Significant rainfall has occurred in all areas. With a medium or high weather risk having been recorded in the south and west of the country, the disease risk here is moderate. However, in the north and east the disease risk is relatively low.
Yellow rust
Yellow rust has now been found at three Live Monitoring sites, but only in one variety (Oakley at Cirencester and Caythorpe in Lincolnshire, and Solstice at Terrington in Norfolk). A medium weather risk was recorded at over half of the weather stations in many regions, and, with the exception of the south-east, the disease risk is high for very susceptible varieties and moderate for others that are susceptible.
Brown rust
Brown rust was not detected at any of the sites, and the disease risk continues to be low.
Mildew
Mildew is present at two of the Live Monitoring sites. At Caythorpe seven varieties, varying in susceptibility, have slight or moderate symptoms. At Telford levels have increased and are now moderate in most varieties. The weather risk was recorded as moderate to low in most areas and, with the exception of the north-west, the overall disease risk remains relatively low.
