Copyright 2006 Central Science Laboratory 03 Jul 2009 CropMonitor Web Feed. http://cropmonitor.csl.gov.uk/ http://cropmonitor.co.uk/wwheat/encyclopaedia/reports/2009/tanspot_09.cfm Tan spot has been confirmed in two fields sampled from Wiltshire for the national wheat survey. Plants from one field have severe symptoms of the disease, with lesions present on leaves and leaf sheaths. The disease is easily confused with Stagonospora leaf blotch (formerly Septoria nodorum). http://www.cropmonitor.co.uk/winterwheat/liveMonitor.cfm Growth stages ranged from the end of flowering (GS69) to grain milky ripe (GS73-75) in CropMonitor trials. Visible septoria had increased significantly at some sites, but levels are typically still below those seen at about the same stage in previous years. Levels of yellow rust continue to rise on Solstice and Robigus and, in recent years, the disease has shown little signs of slowing down through June. While the disease pressure is expected to stay high, the majority of promptly and appropriately protected farm crops are likely to remain unaffected. Mildew levels have barely changed after last week's increases and the threat from the disease at most of the Live Monitoring sites remains low. The warm and humid conditions in the last few days have been favourable for further development of brown rust on susceptible varieties such as Solstice. However, inoculum levels in most crops are now so low that the risk of a significant outbreak of the disease is minimal. http://www.cropmonitor.co.uk/winterwheat/liveMonitor.cfm The Fera/HGCA-funded UK Cereal Pathogen Virulence survey (UKCPVS) conducted by NIAB has verified the presence of a new race of yellow rust on UK winter wheat. The new pathotype was isolated from Solstice in 2008. Subsequent tests showed that Solstice became heavily infected when inoculated with the new race whilst two other previously resistant varieties, Ketchum and QPlus, (both related to Solstice) also suffered moderate to high infection. Humber and Viscount (also resistant but not related to Solstice) also showed susceptibility. Oakley, already known to be susceptible to existing pathotypes, was also more susceptible to the new race. http://cropmonitor.co.uk/wwheat/livemonitoring/2009wheatmonitoring/viewCMReport.cfm?rep_id=39 CropMonitor live-monitoring report compiled by TAG http://cropmonitor.co.uk/FoLCompiledReports/viewReport.cfm?week_id=80 Compiled by Farming Online from reports received from members of the Association of Independent Crop Consultants