Deadly olive tree disease across Europe threatens 95 per cent of crops

Pathogen could cost economies £17 billion

Olive trees across Europe are at risk due to a pathogen wiping out crops.

A deadly olive tree pathogen spreading throughout Europe could threaten 95 per cent of the world's crops, a study has revealed.

The Xylella fastidiosa pathogen, which is transmitted by insects, has wiped out millions of trees across Italy and is now accelerating into plantations in Spain and Greece.

It is feared that the economic cost of the disease could run to £17 billion and prices for consumers will rise.

Last year, France also discovered its first cases of the bacterium.

The US peer reviewed study has warned that over the next 50 years the pathogen, which has no known cure, could destroy many of the crops in Italy, Spain and Greece - which account for 95 per cent of the world's olives.

The lead author of the study, Kevin Schneider, of Wageningen University in the Netherlands, said: "The expected effect could be that there would be a shortage of supply. And I would expect that if prices go up, consumers will be worse off."

The study, which was published in the US Proceedings of the National Academy of Sciences, revealed that economic losses would be £4.3 billion in Italy over the next 50 years if nothing is done to halt the spread.

In Spain, losses would mount to £14.8 billion over the same period, and in Greece it would cost the economy £1.7 billion.

Presently, there is no known treatment to prevent the spread. Control of the disease has so far been limited to the removal of infected trees and the planting of new ones.

The report says that if preventative measures can be taken, then the economic cost could be reduced to £8.7 million a year in Italy.

Olive farmer Gennaro Santoro runs a farm in Puglia and says farmers need to adapt.

"You can't cut down all the olive trees," he told the Olive Times. "We must seek to live with the disease, as farmers have always done."

At the moment the disease has infected 17 per cent of crops in Italy. It was first discovered in the country in 2013 and it is estimated that 60 per cent of crops have been lost since then.

Researchers say the pathogen flourishes in the worst-affected areas due to their climates, and estimate that up to 99 per cent of crops are susceptible.

It presently spreads at a rate of 5km a year but researchers say this could be reduced to 1km if action is taken.

“There are clear guidelines and protocols enacted to prepare as much as possible against the introduction of harmful plant diseases," Dr Schneider said.

"[But] some species can change ecosystems, some have economic impact, and some do not establish successfully at all, and in turn do not cause impact.”

The study has identified two varieties of olive tree that have some resistance and are urging for more research to be done.

It also warns that cultural heritage will be lost as a result.

"You really hear devastating stories of infected orchards that were inherited over generations," added Dr Schneider.

"It's the same orchard that their grandparents were once working on. So how do you put an economic number on the loss of something like this? The cultural heritage value would be far larger than we could compute."

The pathogen also affects cherry, almond and plum trees.