A NEW strategy is being formulated to cope with the growing threat from the late blight strain, EU_37.

This new genotype shows reduced sensitivity to the well-known fungicide, fluazinam and now work done by the AHDB, Scotland’s Rural College (SRUC) and ADAS has produced guidance notes on coping with EU_37.

Last year, AHDB notified its blight network about reports of the UK spread of EU_37 which was first discovered in the Netherlands in 2013. Claire Hodge, of AHDB, pointed out this week: “The dominance of the EU_37 genotype increased substantially between 2016 and 2017. In that time, the percentage of EU_37 samples collected by Blight Scouts who volunteer as part of our 'Fight Against Blight' (FAB) programme rose from 3% to 24%.

"If the frequency of EU_37 continues to increase, the efficacy of fluazinam is likely to be affected further.”

Evidence available suggests that EU_37 has decreased sensitivity to fluazinam and has comparable aggressiveness to another dominant genotype in GB, 6_A1.

Currently, there are blight fungicide active ingredients with 13 different modes of action available in the UK, therefore resistance to fluazinam should not be a major issue for potato production, provided there is sufficient diversity in the use.

As a part of AHDB’s continued research into blight populations, the FAB campaign has been supplying a sampling service, which notifies the industry of outbreaks and risk throughout Great Britain since 2006.

Samples from confirmed reports head to the James Hutton Institute for DNA fingerprinting to check the genotype, results are then presented anonymously via the newly improved FAB website – blight.ahdb.org.uk

UK samples are then fed in to EuroBlight – the late blight network for Europe.

In the 2017 season, 275 registered volunteers captured 158 confirmed samples through the service.