Where the World's Olives Live Side by Side

Walking through the lines of olive trees at the World Germplasm Bank is a fas­ci­nat­ing intro­duc­tion to the large, and often unac­knowl­edged, diver­sity of olives.

From a dis­tance, this olive grove at Alameda del Obispo, a facil­ity of the Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA) on the out­skirts of Córdoba, looks just like any other field.

But a closer look reveals an astound­ing range of shapes and col­ors: from the small green Arbequina to the white Belica and the big and round Gordal olives.

This grove is home for more than 1,000 olive cul­ti­vars from 29 coun­tries, from Iran to the Americas, pass­ing through all of the Mediterranean Basin.

Olive trees from Syria, Turkey, Egypt, Albania, Croatia, Greece, Italy, Morocco, Argentina, the USA and Spain live side by side here.

“Founded in 1972 by the Spanish Government with the col­lab­o­ra­tion of the Food and Agriculture Organisation of the United Nations (FAO) and the International Olive Council, this is the old­est and largest inter­na­tional col­lec­tion of olive trees cul­ti­vars in the world,” Angelina Belaj, direc­tor of the Germplasm Bank, tells Olive Oil Times.

The main goal of this col­lec­tion, Belaj explains, is to gather and pre­serve the largest pos­si­ble share of the genetic diver­sity of olive trees.

The germplasm bank grows two or three spec­i­mens of each cul­ti­var in Córdoba and, in case some­thing went wrong with this olive grove, they also keep a backup — a dupli­cate of it — in another estate the IFAPA runs in the province of Jaén.

“Despite being an impor­tant crop and most of the com­mer­cial olive trees come from just a hand­ful of cul­ti­vars, this species has man­aged to pre­serve a remark­able genetic diver­sity. We believe that there are around 2,000 vari­eties world­wide,” says Belaj.

Some olive vari­eties can have dif­fer­ent names in dif­fer­ent coun­tries, regions or even vil­lages, so the first job of the sci­en­tist work­ing here is to deter­mine whether from a genetic per­spec­tive those names and ori­gins hide known cul­ti­vars.

It’s a sort of detec­tive work that often leads sci­en­tists to trace back the ori­gin of cul­ti­vars whose expan­sion has some­times been inti­mately linked with his­tor­i­cal events and move­ments of pop­u­la­tions across the Mediterranean through­out the cen­turies.

“It’s impor­tant to get to know the genetic part, but also the agro­nomic and mor­pho­logic part. It is use­ful as well to know the lan­guages and his­tory of the ter­ri­to­ries where the olives are grown,” Belaj points out.

“For instance, in Morocco, they have an impor­tant cul­ti­var called Picholine Marrocaine, which from a genetic point of view is exactly the same as the one we call Cañivano Blanco in Andalusia. And it is also iden­ti­cal to an Algerian vari­ety called Siwash.”

“There have always been human migra­tions along the his­tory and farm­ing has never known of bor­ders. Borders are very arti­fi­cial and there has always been an inter­change of knowl­edge and mate­ri­als among coun­tries,” Belaj adds.

Once the cul­ti­vars have been genet­i­cally iden­ti­fied and described from an agro­nomic point of view, the next ques­tion is: What can they be use­ful for?

In that regard, the World Germplasm Bank has become a key source of knowl­edge and mate­ri­als for the sci­en­tists work­ing at the pro­gram for the genetic improve­ment of olive trees — one of the main olive oil-related projects at IFAPA.

“The cen­tral aim of our improve­ment pro­gram is to obtain new cul­ti­vars that have high pro­duc­tiv­ity and high oil yield,” Lorenzo León, researcher and coor­di­na­tor of the pro­gram along with Raúl de la Rosa, tells Olive Oil Times.

Leon’s goal is to cre­ate new vari­eties that are able to pro­duce high-qual­ity olive oil while being able to adapt to dif­fer­ent farm­ing sys­tems.

He and his col­leagues mix exist­ing vari­eties in order to get new ones with the traits they pur­sue.

One exam­ple of those new breeds is the recently cre­ated ​“Chiquitita” vari­ety (and its sis­ters ​“Chiquitita 2” and ​“Chiquitita 3”), which com­bines the good qual­i­ties of Picual in terms of oil qual­ity and pro­duc­tiv­ity and the good fea­tures of Arbequina when it comes to adapt­abil­ity to hedge plan­ta­tions.

“In the last few years, there has been an increas­ing num­ber of high-den­sity hedge plan­ta­tions. However, there are just a few avail­able vari­eties that can adapt to that sys­tem. Hence, one of our aims is to obtain new cul­ti­vars that can per­fectly adapt to that high-den­sity hedge plan­ta­tion sys­tem,” León explains.

Another research field for León and his team at IFAPA con­sists of obtain­ing cul­ti­vars that are resis­tant to dis­eases affect­ing olive trees.

“We have sent mate­r­ial to Italy and the Balearic Islands to eval­u­ate the resis­tance to the Xylella [fas­tidiosa],” Belaj says. ​“We are also work­ing in improve­ment lines such as the resis­tance to Verticillium wilt.”

Caused by a fun­gus, Verticillium wilt is one of the most wide­spread olive tree dis­eases. It inter­rupts and reduces the water move­ment from the roots to the leaves and may lead to leaf and fruit drops.

“The prob­lem is that most of the grown cul­ti­vars nowa­days are very vul­ner­a­ble to this dis­ease. And those that are a lit­tle more resis­tant are not inter­est­ing from an agro­nomic point of view. With the improve­ment pro­gram we want to unite these two qual­i­ties in new cul­ti­vars,” says Alicia Serrano, a researcher at IFAPA.

Taking the results of their work out of the research world and mak­ing them under­stand­able and appeal­ing to farm­ers — who are often very attached to their tra­di­tional cul­ti­vars and farm­ing tech­niques — is one of the main chal­lenges for sci­en­tists devel­op­ing new olive cul­ti­vars.

León admits that step may take time, but he is opti­mistic.

“I think that the genetic improve­ment is not about to fight against tra­di­tional farm­ing, but about offer­ing new alter­na­tives,” he says.

“It’s obvi­ous that through these works of genetic improve­ment we are get­ting new mate­ri­als which may offer good alter­na­tives for the future of farm­ing,” he con­cludes.