Lethal olive tree disease across Europe is worth billions

The disease may just build up the costs of olive oil for customers.

Xylella is considered to be one of the most risky pathogens for plants anywhere in the world. It was first discovered in the country in 2013 and it is estimated that 60 per cent of crops have been lost since then.

Economic losses could be as high as €5bn over the next 50 years for Italy, where at least 1m trees have already died, if nothing is done to halt the spread of the disease and olive groves are not replanted, the study found.

The industry is now fighting the disease by removing infected trees and trying to clamp down on the movement of plant material and the sap-sucking insects, such as spittlebugs, that spread the pathogen.

But if those measures fail, what is going to be the monetary have an effect on of the an infection?

They factored in the different cultivation systems in each of the countries and modelled economic losses under a scenario in which all growing ceased due to tree death.

Researchers have modelled the worst potential impacts of the so-called Xylella fastidiosa pathogen, which has killed swathes of trees in Italy and now poses a dire threat to olive plantations in Spain and Greece, the biggest exporters of olive oil.

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

They also compared this worst case with a scenario where replanting with resistant varieties occurred.

Results showed that, if measures are taken, the overall economic impact could be lowered to around €1.6 billion in Italy, with proportionally similar benefits in Spain and Greece.

Researchers predict that these costs could be significantly reduced if the rate of infection is slowed. They involve tree felling around areas where the disease has gained a foothold to create a cordon sanitaire, needed because many trees can be infected without showing outward symptoms of the disease.

A team led by Dr Kevin Schneider, from Wageningen University in the Netherlands, developed a bioeconomic model of Xylella's future spread and impact.

Researchers warned the disease is likely to leave consumers worse off.

The authors say that whilst their research seems to be at economics, there also are probably huge touristic and cultural losses led to via the bacterium that cannot be left out.

"It's the same orchard that their grandparents were once working on".

Ultimately, the researchers consider that beating the pathogen would require bushes which can be proof against the disease. "The cultural heritage value would be far larger than we could compute".

Several scientific initiatives are attempting to tackle the spread of the bacterium by using insect repelling clays, vegetative barriers and genetic analysis to determine why some plants are more susceptible to the infection than others.

While two varieties of olive tree have been found to have some resistance, the researchers are calling for much more research in this area in order to save the European olive oil industry.

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