Enter keywords and hit Go →

Xylella Fastidiosa Identified in Extremadura

Extremadura joins the Balearic Islands and the Community of Valencia as the Spanish regions with active Xylella infestations.
An olive tree with a twisted trunk and green leaves against a clear blue sky. - Olive Oil Times
Infected olive tree (bacterium Xylella fastidiosa)
By Daniel Dawson
Jul. 15, 2024 15:14 UTC
Summary Summary

Plant health author­i­ties in Extremadura have iden­ti­fied Xylella fas­tidiosa in the autonomous com­mu­nity, enact­ing con­tain­ment and erad­i­ca­tion mea­sures, includ­ing the imme­di­ate elim­i­na­tion of infected plants and estab­lish­ment of buffer zones. The fas­tidiosa sub­species was found in rock­roses, Cytisus plants, and laven­der in Valencia de Alcántara, with no infected olive trees iden­ti­fied, and sim­i­lar out­breaks have been reported in neigh­bor­ing Portugal and the Balearic Islands.

Plant health author­i­ties in Extremadura have iden­ti­fied Xyellla fas­tidiosa in the autonomous com­mu­nity and enacted con­tain­ment and erad­i­ca­tion mea­sures.

Authorities said the fas­tidiosa sub­species (Xylella fas­tidiosa fas­tidiosa) of the deadly plant pathogen was iden­ti­fied in two types of rock­roses, two species of Cytisus plants and laven­der in the hilly region of Valencia de Alcántara in the province of Cáceres.

According to the European Food Safety Authority, Xylella fas­tidiosa is not known to nat­u­rally infect olive trees, and author­i­ties con­firmed that no infected olive trees were iden­ti­fied.

See Also:Xylella-Resilient Groves Are the Future of Apulian Olive Oil

The pauca and mul­ti­plex sub­species infect olive trees and cause Olive Quick Decline Syndrome, which has no cure and has been iden­ti­fied in other Spanish regions.

Extremaduran plant health offi­cials also launched the erad­i­ca­tion pro­to­col, which includes the imme­di­ate elim­i­na­tion of all infected plants sus­cep­ti­ble to the fas­tidiosa sub­species in a 50-meter radius, the estab­lish­ment of a 2.5‑kilometer buffer zone, insec­ti­ci­dal treat­ments against vec­tor species and the start of a sur­veil­lance pro­gram.

Extremadura is Spain’s third-largest olive oil-pro­duc­ing region, yield­ing 68,997 tons of olive oil in the 2023/24 crop year, of which 8,220 tons were pro­duced in Cáceres.

The same fas­tidiosa sub­species has been present in neigh­bor­ing Portugal since 2019, with mul­ti­plex sub­species iden­ti­fied around the north­ern city of Oporto in 2023.

Xylella fas­tidiosa

Xylella fas­tidiosa is a gram-neg­a­tive bac­terium that is known for caus­ing a vari­ety of plant dis­eases. It is a pathogen that pri­mar­ily affects the xylem, which is the plant tis­sue respon­si­ble for trans­port­ing water and nutri­ents from the roots to other parts of the plant. Xylella fas­tidiosa is a sig­nif­i­cant con­cern in agri­cul­ture and forestry because it can infect a wide range of plant species, lead­ing to eco­nomic losses and envi­ron­men­tal dam­age. This bac­terium is trans­mit­ted by insect vec­tors, such as sharp­shoot­ers and spit­tle­bugs, which feed on plant sap. When these insects feed on infected plants, they acquire the bac­terium and can then trans­mit it to healthy plants when they feed on them. Xylella fas­tidiosa can infect both agri­cul­tural crops and orna­men­tal plants, and it has been respon­si­ble for dev­as­tat­ing dis­eases in var­i­ous parts of the world. Some of the well-known dis­eases caused by Xylella fas­tidiosa include Pierce’s Disease, Citrus Variegated Chlorosis (CVC) and Olive Quick Decline Syndrome (OQDS). Efforts to con­trol Xylella fas­tidiosa include the use of insec­ti­cides to man­age the insect vec­tors, as well as efforts to quar­an­tine and remove infected plants to pre­vent fur­ther spread. Research is ongo­ing to develop more effec­tive strate­gies for man­ag­ing and pre­vent­ing the spread of this bac­terium and its asso­ci­ated plant dis­eases.

The news of the dis­cov­ery fol­lowed an announce­ment by local author­i­ties on the Balearic Islands that 37 wild olive trees, known as ace­buches, infected with Xylella fas­tidiosa pauca, were destroyed in Sencelles.

The Balearic Institute of Nature destroyed 103 sus­cep­ti­ble trees over two hectares in the cen­ter of Mallorca, the largest island in the Mediterranean arch­i­pel­ago.

Currently, the pos­i­tive cases for this species are all con­cen­trated in the area near the ceme­tery of this munic­i­pal­ity,” Joan Simonet, a local coun­cilor, told Diario de Mallorca.

“[The inter­ven­tions] have allowed bet­ter con­tain­ment of the bac­te­ria, a fact that favors the con­ser­va­tion of the wild olive trees in good con­di­tion and helps pro­tect the rest of the island and olive plan­ta­tions from the advance of Xylella fas­tidiosa,” he added.

While the first pauca infec­tions were iden­ti­fied in early 2024, Xylella fas­tidiosa was detected ini­tially on the Balearic Islands in November 2016.

A Xylella fas­tidiosa mul­ti­plex out­break in the Valencian Community is the only other active hotspot in the coun­try.

Advertisement

As of April 2024, local plant health author­i­ties reported that the bac­te­ria had infected 26 plant species but no olive trees. They also iden­ti­fied three insect vec­tors, includ­ing the meadow spit­tle­bug, which preys on olives.

Previous Xylella fas­tidiosa out­breaks in the Community of Madrid and Almería in 2018 were suc­cess­fully erad­i­cated, and the areas remain free of the bac­te­ria.

Along with Spain and Portugal, Xylella fas­tidiosa has been iden­ti­fied in France – where author­i­ties said it is unlikely to be erad­i­cated – and Italy.

Since it was first iden­ti­fied in 2013, Xylella fas­tidiosa pauca has severely impacted olive oil pro­duc­tion in Puglia, Italy’s most sig­nif­i­cant olive oil region, and con­tributed to the steady har­vest declines from the record-high lev­els through­out the 1990s and 2000s.



Advertisement
Advertisement

Related Articles