Infield update: the Hutton Criteria


Although blight pressure has been relatively low this season, due to dry conditions, recent heavy rain has created disruption in blight control programmes and caused a deluge of Hutton criteria alerts to be issued around the country.

David Cooke, Senior Plant Pathologist at the James Hutton Institute, talks about the season’s pressures so far and how you can help to improve the research on the late blight pathogen, in order to establish whether spray programmes and the new forecasting criteria are proving effective.

Blight pressure

“At the beginning of the season we saw a few early alerts and received a blight sample in April from Kent which was unusually early, causing concern among growers,” explains Mr Cooke.

“However, since then we have been experiencing dry and unfavourable blight conditions so the inoculum level has been reduced, along with diligent blight spray programmes, meaning that crops have seen generally low blight pressure.

“More recently, heavy rain has caused disruption in blight programmes, and has increased the likelihood of blight infection which has been demonstrated in recent reports of outbreaks coming in.”

Fight Against Blight

“Through AHDB funding, at the James Hutton Institute we are working with ‘Fight Against Blight’ volunteers or scouts, who send in samples of blight affected crops to allow us to see how the season’s blight levels are progressing,” explains Mr Cooke.

“These samples are extremely important as they help us to understand the populations of blight strains that are in the field and help us to comprehend what programmes will be most effective and finally, how well the Hutton Criteria is performing.”

What can you do?

  • If you notice a blight infection, speak to your agronomist about sending in a sample to your nearest ‘Fight Against Blight’ scout
  • Sending in samples can help you to understand your blight infection, while helping pathologists to understand and reduce the risks of fungicide resistance over time
  • Visit the website for more information on scouts and how to become one
  • Follow FRAG guidelines to maintain effective blight control


To sign up to the Hutton Criteria email alerts visit: