A deadly pathogen is spreading across olive trees in Europe, and so far, there is no known cure for it. Xylella Fastidiosa it now said that it is the most deadly plant disease in the world, and the impacts may be tremendous. Besides the gloomy sightings of entire groves destroyed, the devastating effects of the disease, commonly known as “olive tree leprosy”, could cost the industry tens of billions of euros, and have severe impact on the economies of certain regions and the jobs connected with agriculture and tourism, for the next 50 years…
WHAT CAUSES THE DISEASE
The insect-borne bacterial disease is spread by sap-sucking insects called “spittlebugs”, which latch onto their hosts’ water-transportation system, blocking their tubes with a thick mass, and once the infection enters the tree, it limits its ability to move water and nutrients, causing it to eventually die. The insect go on sucking from one tree to another, spreading the disease. The only way to combat the disease is to chop off the infected trees and burn them. As well as olive trees, spittlebugs also attack cherry, almond and plum trees, but also lavender and rosemary, that will all also die from the bacteria. According to research, the disease is spreading at a rate of approximately 5 kilometers per year, like an invisible drought.
WHERE IT ALL STARTED
The first case of Xylella Fastidiosa was discovered in the Puglia region, Southern Italy, when growers started seeing the leaves of their trees browning and becoming crunchy around the edges. Then suddenly, entire groves were dying off, and there was nothing they could do. No one had seen cases in Europe before that, as Xylella was mostly known to have ravaged vineyards in California and groves in Latin America. Scientist believe today that it probably hitch-hiked its way to Italy on an ornamental coffee-tree. It has later on spread to France, Spain and Portugal, and more recently, Greece. Italy, Spain and Greece account for 95% of European olive oil production, and the impact economical is tremendous, besides the fact that entire regions have sadly become devastating sceneries of decimated ancestral groves…
There is no known cure: once the bacteria infiltrates a host, the plant stays infected until it dies.
Scientists around the world are currently working on developing methods to curb the rate of infection, including sprays, barriers and genetic analysis, to find out why some species are more susceptible than others, as 2 varieties of olive trees have been found to show some resistance. So ultimately, researchers believe that seeking resistant cultivars or immune species is one of the most promising, and environmentally sustainable, long-term strategies that agriculture should look at.
Another strategy will also be to try and reduce the population of insects, which would imply mechanical intervention to remove weeds in spring.
Besides all obvious impacts, the olive tree leprosy is emotionally devastating. The olive tree has an enormous importance all around the Mediterranean, it’s symbolic, it has been untouchable through the generations. Sadly, Nature is now proving that nothing is untouchable.