`France Unlikely to Eradicate Xylella, Report Finds - Olive Oil Times

France Unlikely to Eradicate Xylella, Report Finds

By Daniel Dawson
Sep. 20, 2022 13:34 UTC

Xylella fas­tidiosa is unlikely to be entirely erad­i­cated in France after delays and mis­steps by local author­i­ties, accord­ing to a newly-pub­lished report from the European Commission.

The bac­terium, par­tic­u­lar sub­species of which cause the deadly Olive Quick Decline Syndrome, was first dis­cov­ered in French ter­ri­tory on the Mediterranean island of Corsica in July 2015.

Separate out­breaks were later detected in Provence-Alpes-Côte d’Azur in October 2015 and Occitanie in September 2020.

See Also:Xylella Fastidiosa Containment Protocol Proves Effective in Puglia

In the three regions, which are also the most pro­duc­tive olive-grow­ing areas of the coun­try, the audi­tors iden­ti­fied two sub­species of Xylella fas­tidiosa – mul­ti­plex and pauca – that infect olive trees.

However, olive trees infected by Xylella fas­tidiosa were only iden­ti­fied in Provence-Alpes-Côte d’Azur and destroyed fol­low­ing European erad­i­ca­tion pro­to­cols.

These stip­u­late that any of the 300 iden­ti­fied host species within a 50-meter radius of the infected plant – known as an infec­tion zone – are destroyed.

A larger buffer zone with a 2.5 to 5‑kilometer radius (based on the extent of infec­tions in the infected zones and the abil­ity of the bac­terium to spread) is then set up, and all sus­cep­ti­ble plant species must be tested. Combined, these are known as a demar­cated area.

European Commission audi­tors found that French author­i­ties did not con­sider all the rel­e­vant fac­tors of how Xylella fas­tidiosa is spread by human and nat­ural causes. As a result, the author­i­ties’ sur­veys may have allowed the dis­ease to spread out­side of the buffer zone unde­tected.

The audi­tors also found that a lack of detailed pro­vi­sions meant no imme­di­ate plan was in place to destroy infected plants. This resulted in sig­nif­i­cant delays that cre­ated a risk for the fur­ther spread of the dis­ease.

However, the audi­tors acknowl­edged that French author­i­ties set up demar­cated areas in a timely man­ner on the main­land, which pre­vented Xylella fas­tidiosa from spread­ing as it has in Corsica. The entire island is now con­sid­ered an infected zone, but not by the sub­species that infects olive trees.

See Also:Xylella Arrived in Italy from a Costa Rican Coffee Plant, Researchers Say

In Provence-Alpes-Côte d’Azur, where two infected olive trees were iden­ti­fied, the audi­tors said author­i­ties suc­cess­fully estab­lished the demar­cated area in time, pre­vent­ing the spread of the dis­ease from the two orna­men­tal olive trees to oth­ers in the zone.

While French author­i­ties quickly set up demar­cated areas and con­ducted thor­ough test­ing to iden­tify infected plants, the audi­tors found that erad­i­ca­tion of these plants and oth­ers in the infected zones was delayed by up to five months.

These delays were attrib­uted to a pro­longed ten­der­ing period, in which con­tracts are awarded to pri­vate com­pa­nies to erad­i­cate infected plants, move­ment restric­tions put in place dur­ing the Covid-19 pan­demic and the right of prop­erty own­ers to appeal test results.

The audi­tors said delays in remov­ing infected plants and the lack of a coor­di­nated effort to iden­tify and con­trol insect vec­tor pop­u­la­tions raised seri­ous doubts” that Xylella fas­tidiosa could be erad­i­cated in main­land France.

On Corsica, the audi­tors said author­i­ties failed to com­ply with European reg­u­la­tions restrict­ing the move­ment of infected plants. While they acknowl­edged ade­quate con­trols at ports, they said no con­trols were placed on boats leav­ing with sus­cep­ti­ble plant species to Spain or Italy.

On the main­land, the audi­tors said author­i­ties did not set up ade­quate infra­struc­ture to check plant move­ments on roads or ports, mean­ing poten­tially infected plants may have been trans­ported to other parts of France, Spain and Italy.

However, the audi­tors said that local and national author­i­ties had done well to inform the pub­lic about the threat of Xylella fas­tidiosa, which may have helped pre­vent the spread to fur­ther agri­cul­tural areas.

The audi­tors con­cluded the report with six rec­om­men­da­tions for author­i­ties to take to rem­edy the issues they iden­ti­fied.


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