Europe, UK, Ireland

Emerging blight strains continue to be the focus in Britain

Results from 2018 research into the fungicide sensitivity of British late blight isolates was presented at AHDB Agronomists’ Conference in December, with a look forward to 2019.

Dr Alison Lees, a Research Leader at the James Hutton Institute (JHI) – tested fungicides belonging to a range of Fungicide Resistance Action Committee (FRAC) groups for their ability to inhibit late blight.

Dr Lees noted that a limited number of isolates of P. infestans belonging to lineages known to be either established or relatively new to Great Britain were tested. Results of testing genotype 37_A2 provided supporting evidence of its resistance to fluazinam, as previously reported. Findings from samples provided in the 2018 growing season do not provide evidence of specific or multiple shifts in resistance.

However, isolates of genotype 36_A2 were more difficult to inhibit than those of the other genotypes across several active ingredients and appeared to be relatively aggressive.

FRAG-UK guidelines on resistance management in potato late blight remain of high importance and the situation with regard to the emergence of 36_A2 and other genotypes in the context of their aggressiveness, will continue to be monitored over the course of the 2019 season.

Fight Against Blight and Blightwatch both fight against blight and Blightwatch will be continuing for the 2019 season. Fight Against Blight will continue to use blight scouts to collect blight samples, which will be genotyped, and further fungicide sensitivity testing will be included as part of this.

This article by Dr Kathleen Hayes, Knowledge Transfer Officer at AHDB Potatoes was published in the Winter 2018/19 issue of TuberTalk. Go here to read the full publication