United Kingdom
October 2, 2024
Independent monitoring by the Fight Against Blight initiative has confirmed the UK’s first case of EU_46_A1 blight strain which has been found in Lampeter, Wales.
DNA analysis of the sample has been undertaken by the James Hutton Institute to investigate whether it will express any resistance to both CAA and OSBPI fungicides. The gene regions determining resistance to the CAA and OXTP resistance have been amplified and sequenced. The sample was matched with other EU46 samples from continental Europe. In the sample, DNA mutations were present that have been linked to Oxathiapiprolin resistance.
In the case of CAAs, genetic expression is recessive, meaning a homozygous state is needed to confer resistance. In the case of the Lampeter sample, the relevant single DNA mutation was found in the heterozygous state which has been proven to confer a sensitive reaction to the fungicide Mandipropamid (CAA group of fungicides).
This is an isolated case at present, found at a remote ADAS trial site with little commercial production nearby. The site will be monitored throughout the winter and any volunteers will be managed to limit any further spread.
Despite this new information it is important to acknowledge that Mandipropamid remains effective against all blight strains found in the UK*. Syngenta maintains a sustainable and responsible approach to the control of blight and will continue to advise the use of Mandipropamid based products with a mixer partner to ensure maximum control is provided regardless of the strain sensitivity.
For more information and the latest advice on managing blight resistance this season, visit the Syngenta website blight hub
References
* James Hutton Institute sensitivity testing, Dr David Cooke 2022
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