Xylella fastidiosa threatens 1000-year-old monumental olive trees in Europe

olive tree xylella

As unfortunate as it sounds, the deadly pathogen Xylella fastidiosa is currently more dangerous than ever. After several years of destruction in southern Italy, it has now been spreading viscously across more regions in Europe. This includes France, Portugal, Italy, Spain and more. In fact, positive samples of Xylella have been confirmed for the first time in the French region of Occitanie, and local plant health authorities were not pleased with this news. It comes as no surprise, as this pathogen is also known as the ‘olive tree killer’.

olive tree xylella

Caption: Olive tree in Puglia | Image credits ©Canva

Today, it is slowly advancing to regions in Italy and Spain which have incredible cultural heritage and value. Xylella is on the verge of spreading to areas which are home to monumental olive trees, some of which are more than a 1,000-years-old. It is without a doubt that if the pathogen made its way to these trees, it would be tragic.

What is Xylella fastidiosa?

Xylella fastidiosa is a plant pathogen that causes Quick Olive Decline Syndrome (QODS) in cultivars of olive trees. It is carried by xylem-feeding insects, such as spittlebugs, which infect the host while they feed. Once the insect inserts its stylet into the plant and starts to feed, the bacterium blocks the nutrient vessels causing the plant to essentially die from within.

Initial symptoms include dieback of the leaves, wilting, discolouration, etc. In fact, the symptoms very much resemble those which are typical of plant dehydration. For more concrete symptoms of the infection, see the top 9 Xylella fastidiosa symptoms. If your plant is demonstrating more of the listed symptoms, it might be time to worry.

Why is Xylella so dangerous?

At this stage, there is no cure for this plant pathogen. In fact, Xylella fastidiosa has been identified by the European Union as one of the top priority pests. It causes a variety of plant diseases and there is no cure for it.  In addition, the disease spreads incredibly fast. According to an article in Olive Oil Times, the ”disease has spread from 8,000 hectares estimated in 2013, to 8,000 square kilometres”. This is an alarming rate, considering the pathogen was first identified in southern Italy in 2013.

global threat of xylella fastidiosa

Caption: Xylella-infected olive tree at stage of plant death| Image credits ©Shutterstock

Xylella is on the verge of wiping out monumental trees

Xylella fastidiosa has already managed to infect monumental trees in Puglia, Italy. According to Olive Oil Times, two millenary olive trees have been tested positive for the presence of the pathogen. Unfortunately, the Monumental Tree Valley and its surrounding plateau are at extreme risk. It has been estimated, that one third of the monumental olive trees (some of which have been there for more than 1,000 years) have been lost due to Xylella.

As such, farmers are worried that if the infection keeps spreading, the region might lose its cultural heritage as well as economic significance for tourism and olive oil production.

xylella fastidiosa puglia

Caption: Monumental olive trees in Italy are at high risk from Xylella fastidiosa | Image credits ©Canva

New areas at risk of Xylella infections in 2021

It’s not only in southern Italy where monumental trees are at risk. Mallorca (Spain) is also home to stunning monumental olive trees. Examples of such the Tramuntana Valley, also known as Serra de Tramuntana.

The pathogen has been present in Mallorca and it keeps spreading across the island. Some olive farmers fear that the Tramuntana Valley (a World Heritage site) is at high risk of being infected. Should the region be infected with the pathogen, European regulations would apply. Meaning, that the infected monumental trees would need to be uprooted or burned. Special buffer zones and infection zones would apply to the region as well.

One of the partners from the BIOVEXO project consortium, who has an olive farm in Mallorca, emphasised that this would be indeed a tragedy. ”The monumental trees within the Tramuntana Valley must be protected at all costs! They have been there for centuries and we cannot let them die”.

Special attention must be paid by all stakeholders to protect the vitality of EU agriculture as well as plant health.

Top Xylella news in 2020

2020 was an eventful year as regards Xylella fastidiosa. The pathogen has been present in Europe since its identification 2013, however Xylella still poses a threat to global plant health. Take a quick look at the top 7 Xylella events that happened in 2020.

To learn more about Xylella and the latest EU research on this plant pathogen, visit www.biovexo.eu.

Leave a Reply

Your email address will not be published. Required fields are marked *