Aggressive 36_A2 blight strain detected by new rapid genotyping service

Tuesday, 25 June 2019

The recent warm, wet weather in many regions has created the perfect conditions for potato blight development.

AHDB blight scouts, a network of growers and agronomists who submit samples for testing, have submitted a flurry of samples in June – compared to a quiet start to the year after a dry April and May.

In the samples already tested there have been findings of 36_A2, an aggressive strain of blight that has proved difficult to manage in recent years.

Dr David Cooke, of the James Hutton Institute where the AHDB funded testing is conducted, said:

“We have had 15 samples confirmed as blight to date and have genotyped six of these. The first samples from cull piles in South East England were genotype 36_A2.

“The other more recent samples from Essex and Suffolk have been confirmed as 36_A2 with further one from Kent being a mix of genotypes 36_A2 and 6_A1.

“It’s too early to draw conclusions about how the national picture will look, but this gives growers – particularly those in the South East and Eastern England, advanced warning of the strains in their area.”

AHDB’s ‘Fight Against Blight’ service was extended for 2019, so that blight scouts get genotyping results during the season.

Dr Kathryn Hales, Knowledge Transfer Officer for AHDB Potatoes who runs the Fight Against Blight scheme said:

“June samples that are received and confirmed as blight have had genotypes assigned within 4 days.

“It’s likely to be a fast moving picture over the next week or so – so growers and agronomists should keep their eyes on to see the blight strains near them.

“Our website was simplified and improved in 2018, and scouts are reminded to use that, rather than the old app.”

Growers can find more info about the Fight Against Blight, and sign-up as a blight scout via the tools section of the AHDB website.

Submissions from blight scouts at 25 June 2019, view the interactive map here