Olive Trees Battle Dangerous Bacteria

Olive Trees Battle Dangerous Bacteria

According to the website The Olive Oil Source, the olive is among the oldest known cultivated trees in the world, dating back to before written language was created.

Native to Asia Minor, it spread from Iran, Syria, and Palestine before moving on to the rest of the Mediterranean basin some 6,000 years ago.

While these trees have endured the passage of time and outlasted many of the civilizations that once revered them, today they are faced with a disease that could mean their extinction.

A new threat to olive trees

Olive trees near Gallipoli (in the Apulia region of southern Italy) started to show distress as bunches of leaves turned brown and crunchy along their edges. While at first considered an anomaly, soon entire groves were being affected as families who had tended to the trees for generations watched their crops and their profits plummet.

Scientists were brought in and discovered the problem was caused by the plant bacterium Xylella—a reality which was confirmed when the scientists examined the woody heart of the Italian trees.

Italy produces about fifteen percent of the world’s virgin olive oil, worth more than $2 billion each year. Spain produces even more and is now growing concerned by the Xylella outbreak in neighboring Italy.

But they’re not giving up. Scientists and growers are banding together to try and figure out exactly what has caused the Xylella outbreak and if anything can be done to mitigate the damage.

What does Xylella do?

It basically causes the plant to die of thirst from the inside out, passed from tree-to-tree by tiny pests called spittlebugs, which are native to Italy. Sadly, there is no known cure and once the bacteria take hold of the host, the tree remains infected until it eventually dies.

Scientist and growers are working together testing hundreds of cultivars of olives to find some that might in fact be resistant to the bacteria. They’ve only found two possibilities so far, but continue to try and find more.

Giovanni Melcarne and his family have grown olives in the province for over 500 years.

“The olive tree had an enormous importance for our society because it is the symbol,” says Giovanni. “We thought they cannot be touched, are immortal. Now, we are facing a truth that is a natural truth—that nothing is untouchable.”