Leaf layer tested: Newest leaf layer
Summary: The first results of the season are in! Low levels of Septoria tritici has been detected at six sites including two crops of KWS Extase whilst no yellow rust has been detected in any of the fields tested.
As expected for the opening month of the year, the majority of samples have no Septoria tritici present. However, Septoria tritici is being detected in the newest leaf layer from six of the selected fields. Unsurprisingly, this included all three of the fields drilled in September with weak Septoria tritici resistance ratings – RGT Wolverine (5.3), RGT Skyfall (5.8), Elation (4.1).
However, what is more interesting is that Septoria tritici is in the newest leaf layer of KWS Extase (8.0) at two of the sites.
One of these sites is from Malshanger Estates, Hampshire managed by Ian Margettes. He drilled the field on 26th September.
This reflects our understanding that drilling strong varieties earlier in the season does not make them immune from disease, highlighting the importance of taking all factors into account when making fungicide decisions.
Septoria tritici is also present in Extase (8.0) at R H Mason of Wold Newton, Yorkshire. This crop was drilled on 20th October. Using conventional disease management logic, technical manager James Howat and farmer partner Christine Mason didn’t expect to find the disease in a later drilled crop with a strong rating. It highlights the value of the Rapid Disease Detection tool in providing additional layers of information to support fungicide decisions.
Whilst, these results are all relatively low, it will be interesting to see how disease develops and if the stronger rated varieties are able to limit the speed of progression of the disease.
Despite some reports of yellow rust detected in fields during the winter, there is no yellow rust being detected in the newest leaf layer of any of the fields sampled as part of this project.