Farmers in Croatia See Promising Use of Drones

The own­ers of mil­len­nial olive trees in Lun on the Croatian island of Pag are left with­out a har­vest year after year.

Even last sea­son, when they had high hopes, they failed to pro­duce oil from wild olives. This year, they planned to present their extra vir­gin olive oil at an inter­na­tional com­pe­ti­tion for the first time, choos­ing the 2023 NYIOOC World Olive Oil Competition as the venue.

Unfortunately, they failed. ​“There was no fruit that was healthy enough to make at least one batch of top-qual­ity oil,” Želimir Badurina, the founder and pres­i­dent of the Lun Olive Cooperative, told Olive Oil Times.

First, fer­til­iza­tion went wrong. Some fruits that sur­vived the heat wave improved, but the olives turned brown over time, then black and finally fell from the branches. What lit­tle was left was dam­aged by pests – the olive fruit fly, borer and pat­ula (a moth).

The prob­lem is that pro­tect­ing the Lunje olive groves against pests and dis­eases is not pos­si­ble using con­ven­tional meth­ods. The rea­son is sim­ple: the Lunj olive groves cover about 400 hectares of rugged, hard-to-access ter­rain.

Most of the 80,000 trees can­not be accessed by vehi­cles. Even if spray­ing with atom­iz­ers from a trac­tor were pos­si­ble, it would have no effect because the cen­turies-old trees, some of which are more than 2,000 years old, are tall with crowns of 6 to 10 meters.

Due to the slope and rocky ter­rain, the dis­po­si­tion and vari­able spac­ing of the trees, the impos­si­bil­ity of using trac­tors and the lack of work­force pro­tec­tion here, as in quite a few other olive grow­ing areas, espe­cially on the islands, is only pos­si­ble from the air.

“With drones, it would be pos­si­ble to effec­tively treat and pro­tect the entire com­plex of olive groves in Lunje,” Andrea Cantore Badurina said.

The young agron­o­mist, Badurina’s nephew, stud­ied agron­omy in Milan, where he was born. Later, he grad­u­ated from a master’s pro­gram in Zagreb and received his doc­tor­ate in Sardinia, where his par­ents live. After fin­ish­ing his stud­ies, he returned to Lun, where his mother is from.

Cantore Badurina works as a guide in the Gardens of Lunje olive groves, which he pre­serves and pro­tects. He also does sci­en­tific work, fol­low­ing the lat­est devel­op­ments in dig­i­tal agri­cul­ture, espe­cially in olive grow­ing.

He said drones are widely used in other olive-grow­ing coun­tries to col­lect valu­able data, includ­ing soil analy­ses, plant health indi­ca­tors and water and nutri­ent infor­ma­tion.

This data helps farm­ers opti­mize inputs, such as fer­til­iz­ers, water and pes­ti­cides. As a result, they pro­vide timely pro­tec­tion against pests, save time, reduce pro­duc­tion costs and ensure larger and bet­ter qual­ity crop yields.

Several other projects also are under­way in neigh­bor­ing Italy. For exam­ple, in Tuscany, experts are devel­op­ing a model for assisted pol­li­na­tion of olive trees with the help of drones.

The European Union-funded project Olimpolli Montagnani is still in the exper­i­men­tal phase. However, the first tests car­ried out in olive groves in Garda and Tuscany pro­vided encour­ag­ing results.

Instead of increas­ing the pro­duc­tiv­ity of exist­ing olive trees by the 1 to 3 per­cent asso­ci­ated with tra­di­tional meth­ods, Olimpolli Montagnani’s method has increased the pro­duc­tiv­ity by 20 to 25 per­cent.

The uncrewed aer­ial vehi­cle hov­ers above the olive trees, dis­perses the pollen and fer­til­izes the flow­ers. Days with­out wind and rain are ideal for pol­li­na­tion.

Pollen that is still active is col­lected directly from the plants. The olive grow­ers can fly the drones them­selves or hire spe­cial­ist com­pa­nies to do it for them.

The pollen can be stored and used in ideal tem­per­a­ture and humid­ity con­di­tions the fol­low­ing year.

Experts said olive farm­ers with large groves would ben­e­fit from using drones for pol­li­na­tion because they can cover huge areas quickly, fly­ing over trees even in inac­ces­si­ble areas, such as steep slopes or ter­races.

Even in such con­di­tions, the drone allows farm­ers to apply pollen on one hectare of olive groves (about 300 trees) in a few min­utes com­pared to a few hours of man­ual appli­ca­tion.

Furthermore, the air dri­ven by the drone’s pro­pellers favors the simul­ta­ne­ous dis­per­sal of pollen through­out the canopy.

In addi­tion to the pro­duc­tion and land­scape preser­va­tion advan­tages, the project also increases employ­ment oppor­tu­ni­ties for young peo­ple and allows for inno­va­tion across the olive oil pro­duc­tion sup­ply chain.

The project was cre­ated to pre­serve tra­di­tional Italian olive grow­ing, but it can also be applied to high-den­sity and super-high-den­sity groves.

“Our region is lead­ing the way in exper­i­ment­ing with pre­ci­sion farm­ing tech­niques that sus­tain­ably increase pro­duc­tiv­ity, and thus prof­itabil­ity per hectare, while at the same time reduc­ing costs and waste of tech­ni­cal resources,” said Fabrizio Filippi, pres­i­dent of Coldiretti Tuscany, a farm­ers’ asso­ci­a­tion.

“Tuscany is very involved in find­ing new solu­tions to deal with cli­mate change, which will require us to review our agro­nomic real­ity and find solu­tions,” he added.

Back in Croatia, Cantore Badurina is still study­ing how drone pol­li­na­tion might work in the olive groves on Lun.

“We do not yet have sci­en­tific papers on this topic, but only pre­lim­i­nary data, so we can only super­fi­cially ana­lyze the infor­ma­tion pre­sented by the pro­jec­t’s cre­ators,” he said.

“We know that olive pol­li­na­tion is an anemophilic process, that mete­o­ro­log­i­cal con­di­tions affect suc­cess,” Cantore Bandurina added. ​“The use of drones would serve to reduce depen­dence on the wind. However, besides the fact that the drone should pro­duce air­flow, it should also throw out pollen, which is prob­lem­atic.”

How much pollen needs to be col­lected, how long it will take and how much it would all cost are still unknown. So far, there is only pre­lim­i­nary infor­ma­tion. Still, the researchers lead­ing the project are talk­ing about increas­ing pol­li­na­tion suc­cess by 20 to 25 per­cent, which strikes Cantore Bandurina as an excit­ing option for increas­ing pro­duc­tion.

There is no ideal way of har­vest­ing olives yet. Manual har­vest­ing is slow, and mech­a­nized har­vest­ing uses shak­ers and har­vesters, which can dam­age the fruit, leaves and branches.

Scars and wounds can also cause olive can­cer, espe­cially if the har­vest takes place when the weather is wet or imme­di­ately after rain­fall.

The solu­tion devised by a group of stu­dents from Rome may be the best in Cantore Bandurina’s opin­ion.

Their project, OlivAir, is a drone that project exec­u­tive direc­tor Diana Zagarelli said would rev­o­lu­tion­ize the har­vest­ing of olives by remov­ing them from the branch using the wind pro­duced by the pro­pellers.

The drone flies above the trees and can har­vest olives in any ter­rain with­out dam­ag­ing the trees. Since it is elec­tric, it also reduces pol­lu­tion.

From a purely eco­nomic point of view, the speed of har­vest­ing and the recov­ery of olives from steep areas allow an esti­mated increase in prof­its for pro­duc­ers of about 30 per­cent. However, there are also ques­tions, and the biggest one is related to the moment of har­vest.

Ripe olives should not resist air­flow and, there­fore, eas­ily fall off due to the wind gen­er­ated by the drone. However, green olives might not.

According to Cantore Bandurina, farm­ers must decide whether to use hor­mones to treat their olives, so they ripen simul­ta­ne­ously or do sev­eral har­vests with the drone.

“These are all top­ics that I pre­sented to the inven­tors of this drone and that they told me they would pay atten­tion to,” Cantore Badurina said.

If Croatia wants to face its labor short­age, increase pro­duc­tiv­ity, improve self-suf­fi­ciency in pro­duc­tion and increase earn­ings, new tech­nolo­gies in olive grow­ing are inevitable. What can­not be avoided must be accepted.