Greek Olive Growers Face Sharp Declines as Pests Ravage Harvest

Summary

The olive har­vest in Greece is fac­ing a cri­sis due to below-aver­age yields caused by late-autumn rains and humid­ity, lead­ing to sig­nif­i­cant dam­age to olive fruit and a poten­tial 30 – 35% decrease in pro­duc­tion com­pared to the pre­vi­ous year. Proliferation of pests like the fruit fly and gloeospo­rium has caused wide­spread dam­age in some regions, with some farm­ers resort­ing to joint milling prac­tices to address labor short­ages and pro­cess­ing chal­lenges.

The year’s olive har­vest is unfold­ing as a cri­sis in Greece, as ini­tial pro­jec­tions for a below-aver­age olive oil yield increas­ingly become real­ity.

We are likely expe­ri­enc­ing the worst olive oil sea­son in 30 years.- Yiannis Iliadis, Messenia olive oil millers’ asso­ci­a­tion

The impact is most severe in the country’s south­west, where late-autumn rains and ele­vated humid­ity have fueled pest out­breaks that have sig­nif­i­cantly dam­aged olive fruit.

“We are likely expe­ri­enc­ing the worst olive oil sea­son in 30 years,” said Yiannis Iliadis, a mill owner from the vil­lage of Andania and head of the olive oil millers’ asso­ci­a­tion of Messenia in the Peloponnese.

“The fruit fly and gloeospo­rium have taken a heavy toll on the season’s fresh olive oils,” Iliadis added. ​“The olives have already started to rot, and pro­duc­ers are rush­ing to extract what­ever quan­tity of olive oil they can.”

Messenian olive farm­ers and pro­duc­ers said state-run crop-dust­ing oper­a­tions to con­trol the olive fruit fly were car­ried out too late this year, allow­ing the pest pop­u­la­tion to mul­ti­ply dur­ing the sum­mer and inflict wide­spread dam­age.

Koroneiki olives and olives infected by the gloeosporium (brown olives) being processed at a mill in the Peloponnese (Photo: Costas Vasilopoulos)

The agri­cul­tural asso­ci­a­tion of Chandrinos in cen­tral Messenia has also filed a law­suit against those respon­si­ble, argu­ing that delayed pest-con­trol mea­sures exac­er­bated the cri­sis and caused sig­nif­i­cant finan­cial losses.

In nearby Strefi and Aristomenis, millers reported acid­ity lev­els in some freshly pro­duced olive oils rang­ing from 1 to 2, and even higher.

“We have even seen olive oils with acid­ity above two degrees this sea­son due to pest dam­age,” local millers said. ​“We need colder win­ters, which unfor­tu­nately are no longer com­ing.”

Olive oil acid­ity — the level of free fatty acids present in the oil — is a key indi­ca­tor of qual­ity. Oils with acid­ity up to 0.8 per­cent may be clas­si­fied as extra vir­gin, the high­est qual­ity grade, pro­vided they also meet the required sen­sory stan­dards.

Producers said their biggest con­cern this year is gloeospo­rium, a fun­gal dis­ease that causes olives to rot and become unsuit­able for pro­cess­ing.

The fun­gus pro­lif­er­ates rapidly under mild tem­per­a­tures and high humid­ity, caus­ing olive anthrac­nose, which leads to fruit rot­ting and mum­mi­fi­ca­tion and can severely com­pro­mise olive oil qual­ity.

However, pest dam­age has not been uni­form across Messenia, with some areas largely spared.

“Our fresh oils have an acid­ity of 0.3, which shows that qual­ity remains high this sea­son,” said olive farmer Ilias Koroneos from the vil­lage of Lambena.

In neigh­bor­ing Ilia, in the west­ern Peloponnese, har­vest­ing also began ear­lier than usual to min­i­mize pest-related losses.

Local agron­o­mist Panagiotis Gourdoumpas said gloeospo­rium has spread to olive groves at higher alti­tudes, threat­en­ing oil qual­ity and forc­ing pro­duc­ers to rush their olives to the mills.

He added that olive oil pro­duc­tion in Ilia is expected to fall by 30 to 35 per­cent com­pared to last year, due to pest pres­sure and the nat­ural pro­duc­tion cycle fol­low­ing a strong 2024/25 sea­son.

Olive pests have also inten­si­fied pres­sure on grow­ers in Aetolia-Acarnania in west­ern-cen­tral Greece, where gloeospo­rium infes­ta­tions have caused exten­sive fruit drop.

Aetolia-Acarnania is among Greece’s most impor­tant olive-pro­duc­ing regions, cul­ti­vat­ing mainly Koroneiki olives as well as Kalamon (Kalamata) table olives, which are also widely used for olive oil pro­duc­tion.

“Producers in other regions were hop­ing for rain, but for us the heavy rain­fall had the oppo­site effect,” said miller Dimitris Gantzoudis, who oper­ates an olive mill in Stamna, north of Mesolonghi.

“October rains com­bined with mild tem­per­a­tures favored the spread of gloeospo­rium, with dev­as­tat­ing con­se­quences for both qual­ity and quan­tity,” Gantzoudis added.

He said many pro­duc­ers are har­vest­ing as early as pos­si­ble to limit fur­ther dam­age and shorten the sea­son, while some have aban­doned har­vest­ing alto­gether.

Gantzoudis also said labor short­ages have forced him to adopt milling prac­tices more com­monly used in Italy and Spain.

“Due to the lack of work­ers, we can­not process each producer’s olives sep­a­rately,” he said. ​“Instead, we pur­chase the olives and process them together based on qual­ity.”

Joint milling remains rare in Greece, where olives are tra­di­tion­ally processed sep­a­rately due to the frag­men­ta­tion of olive groves, with millers retain­ing a per­cent­age of oil as pay­ment.

“The chal­lenges we face require adap­ta­tion,” Gantzoudis said. ​“Labor short­ages and abnor­mal weather con­di­tions are our biggest prob­lems, and they are unlikely to dis­ap­pear any­time soon.”