`On the Preservation and Maintenance of Monumental Olive Trees - Olive Oil Times

On the Preservation and Maintenance of Monumental Olive Trees

By Ylenia Granitto
Mar. 22, 2016 11:10 UTC

The olive tree is liv­ing proof that beauty has noth­ing to do with per­fec­tion. The evo­lu­tion of the twisted and gnarled wood into the col­lec­tion of lance­o­late and grace­ful leaves reaches the best aes­thetic expres­sion in mon­u­men­tal plants: the slashes imprinted in the sec­u­lar struc­ture express the his­tory over the cen­turies, like the signs of time shape a human face.

With more than 30 years of expe­ri­ence in research and olive oil pro­duc­tion in every seg­ment of the sup­ply chain both agro­nomic and tech­no­log­i­cal, and over 260 sci­en­tific and edu­ca­tional pub­li­ca­tions, Giorgio Pannelli is a lead­ing expert in the main­te­nance of mon­u­men­tal olive trees.

We can­not inter­vene too heav­ily on the struc­ture of the plant if we want to main­tain the mon­u­men­tal atti­tude.- Giorgio Pannelli

Monumental olive trees are large-sized plants with a very rich and solid woody struc­ture,” Pannelli explained. The fea­tures of these plants are due to their age, to the DNA influ­ence on the sta­mina, to the cul­ti­va­tion envi­ron­ment and to the health con­di­tions,” so that in a con­di­tion of pro­longed fer­tile sea­sons, a plant with intrin­sic sta­mina and a healthy struc­ture can reach sig­nif­i­cant dimen­sions over cen­turies and mil­len­nia.

The inter­ven­tion of main­te­nance is needed to ensure a longer life to the plant,” Pannelli affirmed. Especially if the olive tree has been untreated for many years, our action is fun­da­men­tal to avoid break­ages and down­falls, in addi­tion to pre­vent the out­break of dis­eases.

There are sev­eral mon­u­men­tal plants in Greece and Spain, but Italy is the only coun­try with such a large pat­ri­mony, spread out over the penin­sula: from Apulia (2 mil­lion of plants in the province of Brindisi and Lecce) to Tuscany (in the province of Grosseto), from Umbria (Trevi, Terni and Lake Trasimeno) to Abruzzo (in Fossacesia, in the province of Chieti) and Latium (in Palombara Sabina) and many more.

Giorgio Pannelli

Among the most ancient include an olive tree in Magliano in Toscana (Tuscany) which prob­a­bly dates back to the Etruscan period (500 – 800 BC) and the olive tree of Saint Emiliano in Trevi (Umbria), which takes its name from the leg­end of the saint mar­tyred in that place in 303 AD when Diocletian’s edict autho­rized the per­se­cu­tion of Christians.

Regarding the main­te­nance, we first have to estab­lish if our pur­pose is orna­men­tal or pro­duc­tive,” Pannelli clar­i­fies. Productive use is par­tially com­pro­mised, since we can­not inter­vene too heav­ily on the struc­ture of the plant if we want to main­tain the mon­u­men­tal atti­tude,” but if our objec­tive is a good har­vest, we can aim to pre­serve the dimen­sions of the plant and make it man­age­able, to pre­vent the use of ele­vated work plat­forms for prun­ing and har­vest. It is imper­a­tive not to under­mine the mon­u­men­tal aspect of the plant: our goal is to ratio­nal­ize,” Pannelli explained.

If the olive tree is too tall and extended will have com­pro­mised sta­bil­ity. The lat­eral branches are the heav­i­est part of canopy and cli­matic events like wind and snow can cause seri­ous dam­ages, even down­fall, if the plant moves too far from its cen­ter of grav­ity. Therefore, we must prune to limit both the height and the lat­eral expan­sion.

A monumental tree in Villa Adriana before and after restoration.

If you are main­tain­ing a mon­u­men­tal olive tree for an orna­men­tal pur­pose, you also have to dis­close the woody struc­ture,” Pannelli illus­trated. An impres­sive trunk and large branches add majesty to the impos­ing atti­tude of the plant.” Therefore, we must cut off the branches (that oth­er­wise would have been main­tained for the pro­duc­tive pur­pose) which descend to hide the trunk to expose the most con­sis­tent por­tion of the woody struc­ture. In essence, this is the dif­fer­ence between the two types of inter­ven­tions.

A mon­u­men­tal olive trees has an aes­thetic des­ti­na­tion, since pro­duc­tion effi­ciency is under­mined due to the ele­vated costs to main­tain them. Often, pro­duc­ers will use these sec­u­lar trees as emblems of an olive oil pro­duced from younger plants of the same vari­ety. These plants are icons of a ter­ri­tory, a her­itage, a tra­di­tion, a cul­ture,” our expert con­sid­ered.

In Villa Adriana, in Latium, Pannelli con­ducted a three-year project with the olive grow­ing coop­er­a­tive ACO and the col­lab­o­ra­tion of CNR Institute of Biosciences and Bioresources IBBR of Perugia man­ag­ing the main­te­nance of 14 mon­u­men­tal olive trees.

The prun­ing was con­ducted between December and March with mobile plat­forms and fork­lifts that allowed the oper­a­tors to work safely. A proper prun­ing is done with cuts that respect the nat­ural shape of the canopy, the struc­ture and bio­log­i­cal and phys­i­o­log­i­cal mech­a­nisms of the plant. Despite hav­ing elim­i­nated the dense, heavy, or dam­aged parts, it keeps the orig­i­nal appear­ance of the foliage,” as reads the inter­est­ing report of the project.

In addi­tion to the restora­tion, the IBBR con­ducted the vari­etal iden­ti­fi­ca­tion and radio­car­bon dat­ing with inter­est­ing results: the most ancient plants (the old­est is sup­posed to be about 660 years old) belong to an unknown vari­ety.

An inter­est­ing fact about dat­ing mon­u­men­tal olive trees is the dif­fi­culty in cal­cu­lat­ing the age because the inner part of the ori­gin area tends to dis­ap­pear due to dis­eases over the cen­turies. The wood keeps grow­ing lat­er­ally but is inter­nally hol­low, often mak­ing it impos­si­ble to cal­cu­late the exact age, leav­ing sci­en­tists to esti­mate using avail­able data.


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