In Greece, Olive Trees Suffer From Fruit Fly Infection Ahead of Harvest

Last year’s olive har­vest in Greece beat expec­ta­tions, with almost 350,000 tons of oil com­ing out of the mills. The rich pro­duc­tion came after the much-debated drought had min­i­mal effects and there was prac­ti­cally no fruit fly inva­sion that would degrade both the qual­ity and the quan­tity of the olive oil.

But this sea­son is a dif­fer­ent story with the har­vest expected to be slim­mer mainly due to the pro­duc­tion cycle of the olive trees, and the olive fruit fly has again made its pres­ence felt in many areas of the coun­try.

The lack of the usual heat waves that hit Greece every sum­mer and that would ren­der the fly inac­tive, com­bined with the unnat­u­rally high lev­els of rain, enabled the pest to repro­duce and threaten the forth­com­ing pro­duc­tion. A sin­gle female fruit fly can deliver about 200 eggs and after a month the new flies emerge with half of them being females able to make 200 eggs more. They expo­nen­tially increase their pres­ence and it becomes hard to con­tain them if they start hatch­ing.

Giorgos Korinnis, an agri­cul­tur­ist work­ing in Lakonia, which tra­di­tion­ally makes top-qual­ity olive oil, told Olive Oil Times that the infes­ta­tion from the fruit fly is more than obvi­ous this sea­son.

“This is an empty sea­son for us,” Korinnis said. ​“We expect to get only 40 per­cent of last year’s pro­duc­tion which was around 25,000 tons of olive oil for the whole region, and a sig­nif­i­cant part of it will come from olives infected with the fruit fly. So, due to the dam­age the fly causes, I wouldn’t be sur­prised to see olive oils with an acid­ity level of 0.5 or 0.6 when we nor­mally get 0.2 or 0.3, mean­ing that a big part of the oil crop will be of lower qual­ity than what we usu­ally get here.”

Korinnis also explained that the prob­lem started with the mild weather con­di­tions that pre­vailed dur­ing the sum­mer. ​“We had no tem­per­a­tures exceed­ing 35°C (95°F), so the fly could eas­ily repro­duce itself. And many grow­ers did not bother to use any pes­ti­cides to get rid of the fly since they weren’t expect­ing any seri­ous yield, so the fly got the chance to incu­bate in their trees sub­se­quently con­t­a­m­i­nat­ing neigh­bor­ing olive groves with bet­ter prospects and affect­ing this way the olive oil crop of the whole area.”

Konstantinos Papadopoulos of the Papadopoulos Olive Oil Mill near ancient Olympia, told OOT there is an out­break of the olive fruit fly in the area. Some pro­duc­ers took mea­sures to reduce the dam­age, but the major­ity unable to do so mostly due to lim­ited bud­get. ​“Some of the pro­duc­ers we work with will get qual­ity olive oil this sea­son, but gen­er­ally we expect a very low yield of infe­rior qual­ity,” he noted.

In Crete, Peza Union near Heraklion is a big asso­ci­a­tion of olive oil pro­duc­ers. They told us that until now the fruit fly was only active in small pock­ets all over the dis­trict, but they expect it to spread since there is not going to be any more pes­ti­cide appli­ca­tion in the fields due to lack of resources. Nevertheless, and con­trary to the sit­u­a­tion in most parts of the coun­try, they expect an increased pro­duc­tion by 20 to 30 per­cent com­pared to last year.

Reports are also com­ing in from other olive oil-mak­ing ter­ri­to­ries of the coun­try, indi­cat­ing that the sit­u­a­tion is grim.

The island of Lesvos, with its dis­tinc­tive yel­low­ish olive oil, is on the verge of los­ing much of its pro­duc­tion due to the extended fruit fly infec­tion, accord­ing to pro­duc­ers. Weather and the slow response by farm­ers made it easy for the fly to nest and repro­duce. The local admin­is­tra­tion added that organic olive groves, which con­sti­tute 25 per­cent of the island’s olive tree cul­ti­va­tions, also con­tributed to the fly’s spread­ing since their own­ers avoided using any means to con­tain it in order to pro­tect their organic iden­tity.

In the Aetolia-Acarnania region in Central Greece, there are many olive groves infected by the fly and the local pro­duc­ers expect a lesser pro­duc­tion than the pre­vi­ous sea­son. To add insult to injury, many trees that were untouched by the fly were hit by hail that punched the olive fruits to the ground and left pro­duc­ers in despair.

In the neigh­bor­ing area of Lokrida, almost all of the olive oil pro­duc­tion of the area is expected to be affected by the fruit fly. The pro­duc­ers accused the author­i­ties of being slug­gish in apply­ing mea­sures to destroy the fly and asked for com­pen­sa­tion.

There is also a notice com­ing from the author­i­ties of Northern Greece for a very high activ­ity of the fruit fly near the city of Alexandroupoli and other areas, urg­ing the pro­duc­ers there to use pes­ti­cides to min­i­mize the loss.

Back in the day, pro­duc­ers in Greece used to say that a hot and dry sum­mer is all that is needed for olive oil of excel­lent qual­ity. But now, with the weather con­stantly chang­ing, the old wis­dom is not enough and grow­ers and pro­duc­ers have a lot of para­me­ters to con­sider for a suc­cess­ful olive oil crop.

• Agrotypos


• Lesvosnews