Field day for farmers as new GM potato ‘immune to famine fungus’

Late blight, caused by the organism Phytophthora infestans, remains the potato farmer’s greatest enemy to this day.

Each year UK farmers spend £60m keeping the infection at bay with pesticides. In a bad year, losses and control measures combined can account for half the total cost of growing potatoes.

In the latest of a series of field trials, conducted in 2012, the fungus was unable to break down the defences of any of the GM potatoes.

Non-modified plants grown at the trial site were all infected after being denied protection from chemicals.

However, no one can say at this stage how long the GM strain will hold out against blight, which is notorious for its ability to overcome resistance.

Scientists are now conducting further research aimed at identifying multiple resistance genes that will thwart future blight attacks.

“Breeding from wild relatives is laborious and slow and by the time a gene is successfully introduced into a cultivated variety, the late blight pathogen may already have evolved the ability to overcome it,” said lead scientist Professor Jonathan Jones, from The Sainsbury Laboratory. “With new insights into both the pathogen and its potato host, we can use GM technology to tip the evolutionary balance in favour of potatoes and against late blight.”

The Irish potato famine of 1845 was a disaster for the poorer people of Ireland who depended on potatoes for food and income.

Over the following 10 years, more than 750,000 men, women and children died and another two million left their homeland. Within five years of the famine, the Irish population was reduced by a quarter.

Because of late blight, potatoes are one of the crops most affected by chemical pesticides. In northern Europe, farmers typically spray a potato crop 10 to 15 times.