SAN DONACI, Italy (CN) — The vast expanses of olive groves in Puglia’s Salento region were a sad, sickening sight. Mile after mile, nearly every olive tree showed the telltale signs of sickness: large patches of dead brown leaves linked to a devastating plant disease invading the region.
Two years later, it’s gone from bad to catastrophic: Now, instead of clumps of brown leaves everywhere, entire groves of olive trees are leafless and silent, deathly. Nausea may be the best word to describe the sensation the dead groves provoke.
“What is there to say?” an aging sun-darkened farmer in San Donaci said, looking at his gray and leafless olive trees. “No hope.”
He shook his head and went back to working in his vegetable garden under the summer sun. At least his vegetables were growing.
San Donaci, a farming town in the flat Salento region that makes up the bootheel of Italy, offers a dire warning to the rest of Europe about the threat posed by Xylella fastidiosa, a deadly plant bacterium from the Americas now invading Europe. The disease is spread by common insects that feed on a tree’s sap.
With no sure protection against the disease available, iconic olive groves across the Mediterranean basin face a similar fate. The disease is already attacking olives in Corsica, Spain’s Balearic islands and southern France. The bacterium, which causes Pierce’s disease of grapevines in North America, is considered one of the world’s most pernicious agricultural threats because it can infect and kill a wide variety of plants. For example, a strain of Xylella has been attacking California’s vineyards for years and another strain is killing almonds in Spain.
The bacterium’s presence in Puglia’s olive trees was first announced in 2013. Scientists said it likely entered Europe through the global trade in exotic plants.After its discovery, alarm bells rang out: The pathogen, European and Italian officials said, had to be stopped.
Emergency measures put into place were drastic: Infected trees and other trees within a large radius were ordered destroyed. But orders to cut down and uproot ancient olive trees were met with anger and alarm. The idea of ripping out precious olive trees was unthinkable for many.
At the same time, doubts about the exact cause of the olive tree sickness sprang up, too, with some scientists saying the new disease was wreaking such havoc because of years of overuse of herbicides and pesticides in Salento’s olive groves. More sinister theories circulated too linking the disease to nefarious plots hatched by the mafia, land speculators and corrupt scientists.
Farmers resisted the orders to destroy their trees and staged protests. Environmentalists joined the fight, arguing organic treatments and ending the use of chemicals would cure the sick trees. Many politicians backed the resistance, and Italian prosecutors added to the confusion by opening an investigation into the scientists who first identified Xylella as the cause of the sick trees.
Seven years later, the Salento is a disaster zone where every faction in this acrimonious debate seems to be a loser.
Farmers who resisted cutting down their trees now own trees that don’t bear fruit. The only sign of life on most trees are green shoots rising from the trunk. But even these shoots eventually may become infected and die.
Scientists and government officials who advocated the culling of infected trees and other containment measures, such as grass mowing and tilling to contain bugs that spread the bacterium, can’t claim much success either. Despite wide-scale containment efforts, the disease has spread beyond Salento and continues to march north.
Farmers have good reason to be confused about what they should do.
“Even the experts don’t know why there’s this sickness,” said Vincenzo Albanese, a 68-year-old olive farmer, who was tilling the ground in an olive grove with a tractor. “They come from the university and study, but they can’t figure it out.”
There was talk of defeating the disease through heavy pruning. But, he said, that’s not proven to be true. Farmers also have been told to replace their trees with varieties believed to be resistant to Xylella.
He shook his head. “We don’t know what varieties to plant. They say some varieties can’t be attacked, but that’s not how it is,” he said.
Farmers are being told to plant an olive variety called Leccino, which is from Tuscany. But he was doubtful it can’t be attacked by Xylella. Besides that, he said Leccinos don’t make as much oil.
With so much uncertainty, farmers aren’t going to cut down their trees, he said.
“There is nothing for sure,” he said. “No one is going to risk cutting down trees because of the high costs.”
He said the outbreak could have been contained, but that it was too late now.
“When there were the first hot spots near Lecce, there was an order to cut down those sick trees, but they didn’t want to do it,” he said. “When you have a sick finger, you’ve got to cut it off otherwise you might lose a hand in the future. Instead, they let it go and the infection went walking.”
Like many others, including scientists, he pinned the blame for the spread of the disease on environmentalists and politicians who resisted orders to eradicate sick trees.
But could the disease have been stopped?
Marco Scortichini, a plant pathologist and Xylella researcher at Italy’s Council for Agricultural Research and Agricultural Economy Analysis, doesn’t think so.
By the time the foreign pathogen was first identified as the cause behind a browning of leaves in olive trees, up to 1 million trees may have already been infected, he said.
“To think Xylella could have been eliminated from such a vast area in which it had become so widely entrenched is technically impossible,” he said in an email to Courthouse News.
Scortichini has become a leading scientific voice against plans pushed by the European Union and the Italian government to stop the bacterium by eradicating newly infected trees and replacing them with new resistant varieties, such as Leccino. He’s also cast doubt on whether Xylella is the culprit. In a 2019 study, he found Xylella was not detected in 3,300 of 5,378 sick trees.
In August, he published a study showing infected trees given a regular treatment of zinc, copper and citric acid were brought back into a reproductive state. He also believes the soil in sick groves needs to be made more fertile.
“Curing plants doesn’t mean eliminating the pathogen,” he said. “The cure aims to reduce the quantity of the pathogen in the plants to such a level that production still happens.”
He said farmers initially were wrongly led to believe Xylella was impossible to contain. Instead, scientists should have done the opposite and told farmers they needed to learn to live with the disease in a sustainable way, he added.
“The dogma, ‘Xylella can’t be cured,’ created negative expectations for any method meant to improve the situation,” he said.
For now, though, the restoration plan centers on removing infected trees and planting olive varieties deemed resistant to Xylella. To that end, this summer the regional government said about $47.5 million was ready to be distributed for new plantings on 7,000 hectares in the province of Lecce.
But there are fears this strategy will rob Salento of its biodiversity by replacing its ancient olive trees — principally made up of the Ogliarola salentinaand Cellina di Nardòvarieties — and lead to intensive olive plantation farming practices similar to those in Spain. Italy’s environmental ministry, for example, has objected to the replacement plans, saying it reduces olive tree diversity while leaving the newly planted trees still susceptible to future epidemics.
Opponents of removal plans also say all is not lost even if most of Salento’s trees now appear dead: They point to how most seemingly dead trees still have green shoots, known as suckers, sprouting from their bases.
“A desiccated tree, especially if there are suckers on them or other signs of life, is not a dead tree,” said Margherita Ciervo, a geographer and Xylella researcher at the University of Foggia.
She’s now concerned the push to remove Salento’s sick olive trees will speed up since funds became available for new plantings. She said landowners might also be tempted to eradicate trees to make room for more profitable enterprises.
“This is the danger,” she said. “The land will be cleared so it can be occupied by other activities, which will be, or at least seem to be, more profitable. Imagine photovoltaic fields rather than fields for olive — or fields for super-intensive olive plantations.”
Fears that unscrupulous landowners and criminal groups are seeking to destroy the old sick olive groves and make way for more lucrative endeavors have been reinforced after numerous suspicious fires broke out in Salento this spring and summer. Hundreds of trees have gone up in flames and fire authorities believe most of the blazes were set intentionally, according to news reports.
Meanwhile, many scientists are exasperated by the ongoing debates about what’s causing the sick olives and the inaction to tackle the epidemic. A recent study warned that unless drastic measures are taken to combat the disease it could spread throughout Italy, Spain and Greece in the next 50 years and cause up to $28.4 billion in damages. The study said most of those damages could be prevented by planting new groves of resistant varieties.
In light of the coronavirus pandemic, when so many people deny the seriousness of the novel virus, many are drawing parallels between the Xylella disease, sometimes called the leprosy of the olives, and the Covid-19 pandemic.
“It is impossible to ignore the parallels between the Xylella-olive outbreak in Puglia and the Covid-19 outbreak, particularly in the U.S.A.,” said Rodrigo Almeida, a plant disease expert and Xylella researcher at the University of California at Berkeley, in an email.
“Both have strong anti-science movements arguing against basic facts,” he said. “Unfortunately, both outbreaks have had unnecessarily harsh consequences due to this societal failure.”
Almeida said allowing the disease to spread in Puglia has led to “devastation to the olive industry and associated economy, the landscape, and the local cultural patrimony.”
Similarly, he said, “in the U.S.A. two hundred thousand citizens have died of Covid-19 so far, the economy has collapsed and millions are unemployed, and there is still no national policy in place to address the crisis.”
He said the Xylella and Covid-19 outbreaks “could have been limited and contained if adequate policies were implemented in a timely manner.”
For Albanese, the farmer plowing up grasses in a dying olive grove near San Donaci, the tragedy taking place among the olives of Salento, combined with the coronavirus pandemic, is an unmistakable ill omen for the planet.
He said the loss of the trees means so much for Puglia and threatens to end the region’s rural economy.
“There’s an economy that is being lost,” he said. “Jobs, income, so much, that are going away. Everyone is suffering.”
He said farmers are unwilling to cut down their iconic and ancient trees because they have been so central to life in Salento for centuries.
“When you see a neighbor that is leaving, how do you feel?” he said. “That’s how it is with these trees.”
For now, he and other oil makers are doing what they can to try and save their trees: pruning, grafting, improving the soil, applying treatments. A new potential and cheap cure, he said, involves spraying vinegar on his trees.
“People are saying it partly works because the acidity of vinegar may clean the infection from a tree,” he said. “We’re doing treatments with vinegar out of hope. Spending 100 euros doesn’t cost anything. What’s important is that you don’t lose the tree.”
With sadness in his voice, he said the epidemics show something is wrong.
“The world is sick now,” he said, his tractor’s motor chugging noisily under him. “The world is sick. And they don’t want to save it. If you save the world, you save the economy.”
Courthouse News reporter Cain Burdeau is based in the European Union.