EuroBlight has published initial results for the 2025 potato season, in response to concerns regarding the impact of newer late blight strains EU43 and EU46.

EuroBlight is a multi-disciplinary, multi-actor consortium and network, and includes input from the James Hutton Institute. JHI’s Dr David Cooke says warm and dry weather across many potato-growing regions last year – especially March-July – reduced blight pressure for much of the season, although more than 1200 samples from across Europe were genotyped.

Key findings so far:

  • The P. infestans population in Europe remained dominated by the EU36 genotype, which made up around one third of samples
  • The decline in EU43 has stabilised – its overall frequency rose slightly but increased strongly in France, and was also found in Switzerland and Latvia for the first time
  • EU46 increased from 4% to 7% of samples and spread to more countries including England, Norway, Sweden, Latvia and France
  • EU36 dominated in western and central Europe, while more genetically diverse ‘other’ types were more common in north-eastern Europe
  • The relatively new clones, EU43 and EU46 – with reported resistance to some active fungicide ingredients – have been broadly suppressed through modified approaches to fungicide use, with more mixing and alternation of the Fungicide Resistance Action Group (FRAC) active ingredient groups
  • The overall frequency of EU43 had decreased from 23% in 2023 to 9% in 2024 with a slight increase to 12% of all early samples in 2025, and a marked variation between countries

EU46

Although the frequency of EU46 sampled across European crops increased from 4% in 2024 to 7% in 2025, again there was considerable regional variation:

  • Decreased in the Netherland to 1%, from a sample of 69
  • Not detected in Denmark, from a sample of 103
  • Increased in Belgium to 5%, from a sample of 39
  • Increased in Great Britain to 20%, from a sample of 278
  • Broadly the increase due to a range expansion to England, Norway, Sweden, Latvia and France

EU36

EU36 is an aggressive genotype and dominant across many parts of Europe, although there was a fall in overall frequency from 52% in 2024 to 34% in 2025. Once more, there was considerable regional variation:

  • EU36 made up 43% of samples in the Netherlands
  • 64% in France, and
  • 74% in Belgium
  • Bar a single sample in Denmark, it was not found in the Nordic countries

Other significant blight clones

  • EU41 increased slightly from 2% in 2024 to almost 5% in 2025 and remains localised, mainly in Norway and Denmark where it comprised 2-5% of the population, and in Scotland, where it comprised 25% of the 113 samples
  • EU45, which had been steadily expanding after its initial sampling in 2019 to comprise 4% of the samples in 2024, fell to 1% with its range expanded to eight countries, including Poland
  • EU37, which is resistant to fluazinam, stayed at a very low level, around 1%, compared with its high of 14% in 2017 and 2018
  • EU47, which has novel virulence against R8 and R9 resistance genes, was first reported in 2024 but was not detected in 2025 – this may be linked to the reduced blight pressure and smaller population size