Growers urged to be vigilant for new potato blight strain

Irish potato growers should be concerned about a fungicide resistant strain of potato blight, a leading expert on blight has warned.

The EU43 strain of potato blight, first recorded in Ireland last year, has been causing concern for potato growers throughout the country after outbreaks of the pathogen in Europe.

The threat from the EU43 has been highlighted by Dr Jean Beagle Ristaino, who has spent time in Ireland on a Fullbright fellowship researching her upcoming book, The Potato Plague, and working with the Department of Agriculture on research into the blight pathogen that caused the Great Irish Famine.

Speaking to the Irish Farmers Journal, Dr Ristaino said the new strain of blight is not widespread in Ireland yet but growers should remain vigilant.

“No one thought that this pathogen could become resistant to the multi-site fungicide,” she said.

“It’s here but it’s not widespread, like it is in Denmark, but it is something to be concerned about.

“The researchers in Ireland are looking at different chemistries and different mixtures of fungicides to control late blight rather than using single compounds to stop the resistance from developing.”

Pathogen

Dr Ristaino held a public lecture at the Royal Irish Academy last month on the potato blight pathogen that caused the Great Irish Famine.

In 1845, the Phytophthora infestans pathogen entered Irish shores and devastated the potato crop, leading to a seven-year long famine in which over one million people died.

Two years earlier, the same pathogen had caused potato blight in the northeast region of the United States and it was unknown where it came from or how the plant disease could be controlled.

Dr Ristaino’s research has pinpointed the start of the outbreak to the Andes in South America and it then migrated to the US, most likely through trade.

“Phytophthora translates to ‘plant killer,’” she added.

“It’s a real challenge and it’s a threat to global food security.

“It never disappeared after the famine as growers in Ireland know well. It’s still here and as aggressive as ever.”

Dr Ristaino works for the Department of Entomology and Plant Pathology at North Carolina State University.

Although her research focuses on tracing the historic nature of blight, much of her scientific analysis looks at preventing future outbreaks of the disease.

She said that plant collections like those at the National Botanic Gardens in Glasnevin are vital to understanding past famines.

“What’s valuable about those historic collections is that you can use them to track epidemics of the past and you can use them to understand plant biodiversity. They have been integral to my research into tracking the spread of this plant killer.

“I just want to wave the flag for maintaining these historic collections,” she said.

Read more

New blight strain EU43 is causing concern