In season genotyping introduced to stamp out aggressive blight strains

We are pleased to announce that a new contract, which will help fund the successful Fight Against Blight service has been agreed with the James Hutton Institute.

The funding will enable growers and agronomists to continue submitting samples for analysis as well as fungicide testing to follow on from the work conducted in 2018.

One key aspect of the new proposal contains provisions for in-season genotyping: previously growers had to wait until the end of the season, and after implementing a blight spray programme, to receive results from any samples submitted. This will enable growers to use the genotyping data to inform their blight management decisions.

Last season’s Fight Against Blight

Due to last year’s warmer weather, our Fight Against Blight campaign saw fewer samples submitted compared to 2017.

Despite last year’s warmer weather over 250 samples submitted via our Fight Against Blight service.  However there were only 40 outbreaks reported in 2018 in comparison to the 158 in 2017 s

More interesting perhaps, that isolates of the 36_A2 genotype found in the samples increased by 15% compared with the 2% found in 2017.

While researchers are still trying to build up a full picture of this genotype, the increase in frequency of 36_A2 in an overall low blight pressure year and its spread in continental Europe suggest it is causing an aggressive form of blight.

Research at the James Hutton Institute showed that the genotype was more difficult to inhibit than other lineages, producing the largest lesion sizes under the lowest doses with four key fungicide active ingredients used to combat blight.

As the doses applied were well below the rates applied in the field, the data do not give evidence of 36_A2’s resistance to the fungicides used. So far, 36_A2 has established itself in the East of the country but has not yet been found further north than Lincolnshire or in the North or West.

Last year also saw a drop in the number of samples submitted containing the 37_A2 genotype: from 24% observed in 2017 to 16%.

If you grow potatoes or are an advisor why not support the Fight Against Blight service by registering as a blight scout? Your samples are crucial for understanding the genotypes causing late blight disease and provide a direct benefit to you and the GB industry to improve growers' blight management practices.

You can also listen to the latest AHDB Podcast, which explains the Fight Against Blight service and the research being carried out to help stamp out the disease.