Olive Tree Blight in Italy Threatens Mainland Europe

An olive tree infected with Xylella Fastidiosa is the sole survivor in what remains of an orchard in the countryside near Ostuni, in the Puglia region of Italy. (CAIN BURDEAU, Courthouse News Service)

MASSERIA BRANCATI, Italy (CN) — Corrado Rodio walks outside the thick stone walls of his family’s ancient olive oil mill and farmstead, the Masseria Brancati, and strolls over to a 2,000-year-old olive tree at the farm’s entrance. “It was planted by the Romans,” he says. But will it survive a catastrophic disease that’s spread north and now is only a few miles away from Rodio’s farm? Rodio doesn’t think his trees will be spared.

Xylella will arrive here and it will get everywhere,” he says gloomily.

Puglia, the “heel” of Italy’s extreme southern “boot,” is in its fifth year of a catastrophic outbreak of Xylella fastidiosa, a deadly bacterium endemic to the Americas. In the United States, the disease is known as Pierce’s Disease.

Strains of Xylella are now in Europe, and the EU is scrambling to contain the potentially disastrous outbreak. EU officials warn that Xylella, left unchecked, could cause widespread damage to a variety of crops and ornamental plants throughout Europe and Britain.

So far catastrophic damage has been limited to Puglia, where the disease broke out five years ago in olive trees farther south in the Salento, about 100 kilometers south of the Masseria Brancati.

Corrado Rodio stands by an olive tree planted during the Roman era. CAIN BURDEAU, Courthouse News Service

The infections have spread and the new line of defense, where dozens of trees are being cut, is only a few miles south of the Masseria Brancati —or Brancati Farm — which was built on a coastal plain of the Adriatic Sea, affectionately known as the “the Plain of the Thousand-Year-Old Olives.”

The disease looms large on this olive grove plain, watched over by the beautiful coastal city of Ostuni and its brilliant white buildings.

Down on the Plain of the Thousand-Year-Old Olives the ancient trees still produce olives and their valuable oil, and also draw visitors from all over the world.

In a troubling development, a tree on a highway running through the plain recently was found infected with Xylella. It was quickly cut down and removed, as required by EU and Italian officials who are seeking to contain the contagion by cutting down infected trees and any other olive trees within a 100-meter radius.

Puglia has become a land of tragedy. Thousands of trees have been cut down since 2013. Millions more are at risk of infection, and not just in Italy. Spanish officials announced this spring that Xylella had been found in an olive tree in mainland Spain near Madrid. Xylella strains have infested Corsica and mainland France too.

In addition to culling infected trees, farmers have been asked to prune heavily and rid their fields of grasses. Xylella is carried from olive tree to olive tree by flying meadow bugs.

Italian authorities this spring urged commercial olive growers to use pesticides and herbicides to kill the bacterium’s vectors, common spittlebugs.

Strains of Xylella have caused damage to citrus trees in Brazil and vineyards in California as well. Scientists warn that the bacterium has the potential to infect plants around the world.

The Plain of the Thousand-Year Olives. (CAIN BURDEAU, Courthouse News Service)

Puglia is Italy’s top producer of olive oil, and many of this region’s charming landscapes are covered in olive orchards. The pest’s arrival in Puglia and the drastic response required by Italian and EU official to cull infected trees has been dramatic.

It’s a saga colored by protests from farmers and environmentalists, political intrigue, images of heartbroken farmers mourning the loss of old olive orchards, and even allegations, now under investigation by magistrates in Lecce, that the disease was intentionally brought to Italy with criminal intent.

Clouding matters has been a political, legal and scientific fight over what in fact has caused olive trees in Puglia to get sick. Large segments of farmers, environmentalists and the general public believe the government mandates are too heavy handed, politically driven and scientifically unfounded.

These farmers, and some agronomists, blame the disease’s rapaciousness on years of poor farming practices in the Salento area, including overuse of pesticides and herbicides.

A vigorous scientific debate rages over the root causes of Xylella and how to deal with it. The disease was first noticed in the Salento area of Puglia in 2012. Many orchards in that area have been destroyed.

But there are signs of hope too in the Salento. Scientists, agronomists and farmers are working together to keep sick trees alive and plant new orchards with resistant stocks.

This fieldwork includes spraying damaged trees with copper products, hauling in more organic-rich soils and doing better pruning.

Grafting specialists are at work too, reviving sick trees with Xylella-free olive varieties, including wild varieties.

In the meantime, Rodio, the masseria owner, has done everything he can do.

He’s cut the grass in his olive groves several times this wet spring and redoubled efforts to make sure his trees are healthy. Now he’s waiting for authorities to decide what kind of biological products he can use on his masseria, which boasts an organic certification. He is exempted from having to spray herbicides and insecticides, as has been mandated for nonorganic commercial olive growers.

“I’ve cut the grass down to zero,” he says, carrying on his family mill’s traditions after seven generations. “We’re waiting for authorization on what biological products we can use.”

He checks his smartphone for an update from a product provider he’s working with. Nothing yet.

Just then, another group of tourists shows up to visit his famous masseria.

He introduces himself, and guides them over the grounds, under the twisted and gnarly olive trees thousands of years old.

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