A NEW strain of British genetically-modified potato appears to be immune to blight.

Late blight, caused by Phytophthora infestans, is still the potato farmers greatest enemy. UK farmers spend about £60m a year on sprays to keep it at bay.

In a bad year, losses and control measures can account for half the total cost of growing potatoes.

In northern Europe, late blight sees farmers typically spray a potato crop ten to 15 times – and up to 25 times in a bad year.

The 2012 field trials were managed by The Sainsbury Laboratory and conducted at the John Innes Centre plant research institute in Norwich. While blight failed to affect any of the GM potatoes, it infected all of the untreated non-modified plants.

Scientists are now working to identify multiple resistant genes that will thwart future blight attacks.

The research focused on Desiree potatoes and reinforced blight resistance while maintaining crop characteristics that producers and consumers like.

The aim was to produce a crop that could fight off blight without the use of chemicals.

Potatoes containing a gene from a super-resistant wild strain from South America were grown. They were not only unaffected by blight, but also produced a much greater potato yield.

Tubers from each block of 16 GM plants weighed between six and 13 kilograms compared with 1.6 and five kilograms for non-GM plants.

The trials were funded by the Biotechnology and Biological Sciences Research Council and The Gatsby Foundation.

The hunt for multiple resistance genes is a joint project between the UK researchers and American company Simplot.

Prof Ian Crute, from the Agriculture and Horticulture Development Board, said the fight against blight had raged for 170 years. “Now finally, we have the knowledge and technology to stack the odds in our favour,” he said.

“Surely, we must ensure that this scientific advance is exploited swiftly and not left on the shelf unexploited.”