Spain's Olive Oil Sector Launches Ambitious Research on Xylella

Xylella fastidiosa is a serious concern for Spain's olive oil sector and its interprofessional body is supporting research efforts to fight it.

Oct. 29, 2018
By Rosa Gonzalez-Lamas

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The Span­ish Olive Oil Inter­pro­fes­sional asso­ci­a­tion has part­nered with sev­eral insti­tu­tions to com­plete an ambi­tious research project that will study how to con­trol and erad­i­cate Xylella fas­tidiosa, an emerg­ing pathogen that has become one of the olive oil sector’s main con­cerns.

Spain’s National Insti­tu­tion for Research and Agrar­ian Food Tech­nol­ogy (INIA) is col­lab­o­rat­ing with the Inter­pro­fes­sional in the effort.

INIA acts as a liai­son between var­i­ous research groups inves­ti­gat­ing Xylella fas­tidiosa. This has resulted in the open­ing of six new research lines that address the prob­lem from many angles which aim to develop an inte­grated strat­egy that can pro­vide an ample spec­trum response to min­i­mize the risks the pathogen poses to Spain’s olive groves.
See more: Arti­cles on Xylella
This com­pre­hen­sive approach pro­poses to gen­er­ate knowl­edge about Xylella fastidiosa’s behav­ior, vari­ables, prop­a­ga­tion through vec­tors, and con­trol of the insects respon­si­ble for its dis­sem­i­na­tion to design effec­tive strate­gies that can put a halt to its expan­sion. This includes the iden­ti­fi­ca­tion of the vari­eties of olive trees that appear to be more tol­er­ant or resis­tant to Xylella.

Xylella fas­tidiosa is spread through insects that feed them­selves from the xylem in plants. It mul­ti­plies within the vas­cu­lar sys­tem to the point it can clog it and obstruct the flux of raw sap, mainly water and min­eral salts, pro­vok­ing symp­toms related to hydric stress and lack of nutri­ents that range from wilt to the death of the plant.

Dif­fer­ent kinds of plants, mostly woody species as olive, nut, cof­fee, or almond trees can host Xylella fas­tidiosa, a bac­terium with many geno­types that man­i­fests itself dif­fer­ently depend­ing on its host plant. No effec­tive treat­ments have yet been iden­ti­fied, except for the con­trol and erad­i­ca­tion of the plants infected and the insects that prop­a­gate it. This makes Xylella fas­tidiosa a very unpre­dictable men­ace, not to men­tion that it is also dif­fi­cult to iso­late and repro­duce in lab­o­ra­to­ries, which makes its inves­ti­ga­tion chal­leng­ing.


The three-year-long research project’s six lines of inves­ti­ga­tion and insti­tu­tions in charge are:

  • Analy­sis of risks based on the regional behav­ior of Xylella fas­tidiosa in dif­fer­ent olive grove zones through­out Spain, con­sid­er­ing dif­fer­ent cli­mates, olive vari­eties and cul­ti­va­tion sys­tems. This will help cre­ate guides to opti­mize erad­i­ca­tion pro­grams and the con­trol of poten­tial vec­tors (Valencia’s Insti­tute of Agrar­ian Inves­ti­ga­tions – IVIA.)
  • Diag­no­sis, genet­i­cal struc­ture and host plants of Xylella fas­tidiosa found in Spain, mainly in areas with olive trees, to develop new diag­nos­tic tech­niques (Span­ish National Research Coun­cil – CSIC.)
  • Patho­gen­e­sis of the Xylella geno­types iso­lated in Spain with the objec­tive of bet­ter under­stand­ing the effects of olive tree infec­tions and their degree of aggres­sive­ness (Uni­ver­sity of Gerona.)
  • Char­ac­ter­i­za­tion of the infec­tious process and how each Xylella geno­type acts in the main vari­eties of olive trees and wild olive trees, with a view to cre­at­ing an olive tree germplasm bank and explor­ing how each vari­ety behaves in situ (Insti­tute of Agroen­vi­ron­men­tal and Water Econ­omy Research (INAGEA) of the Uni­ver­sity of the Balearic Islands.)
  • Biol­ogy and ecol­ogy of poten­tial vec­tors trans­mit­ting Xylella fas­tidiosa to deter­mine their role in the epi­demi­ol­ogy and dis­ease con­trol in olive trees (Insti­tute of Research and Agro­food Tech­nol­ogy (IRTA.)
  • Sci­en­tific bases for the trans­fer and com­mu­ni­ca­tion of dis­eases caused by Xylella fas­tidiosa in olive trees (Insti­tute of Agrar­ian, Fish­ing, Food and Eco­log­i­cal Production’s Research and Train­ing of the Junta de Andalucía (IFAPA.)

In Europe, Xylella fas­tidiosa first appeared in 2013 in South­ern Italy, where it has proven very dif­fi­cult to con­trol. In Spain, it was first detected in 2017 in the Balearic Islands, where its pres­ence in olive groves has been iden­ti­fied in Majorca, Menorca, and mainly Ibiza.

Ali­cante was the first province in con­ti­nen­tal Spain where Xylella was iden­ti­fied in June 2017. In April 2018 Xylella fas­tidiosa was for the first time iden­ti­fied in olive trees within con­ti­nen­tal Spain, in Madrid, where three hun­dred trees have been elim­i­nated. Accord­ing to Blanca Landa, one of Spain’s top experts on Xylella, these out­breaks do not appear to be related.

Teresa Pérez, the Inter­pro­fes­sion­al’s man­ager, affirmed the orga­ni­za­tion has always evi­denced a strong com­mit­ment with the advance­ment of inno­va­tion in all sub­jects where knowl­edge is crit­i­cal to Spain’s olive oil sec­tor.

An aver­age of 11 per­cent of our bud­get is devoted to R&D,” Pérez told Olive Oil Times, adding that Xylella has been a pri­or­ity for Spain’s olive oil sec­tor and the rea­son for which the Inter­pro­fes­sional had been for some time in the search of solid research projects like this one.

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