Dalmatian Agronomists Experiment with New Pruning Methods

Carrying scissors in one hand and a saw in the other, Stjepan Dević prunes a tree in five minutes.

Pruning in Croatia olive groves is in full swing, and the new trend is trimming trees into a polyconic vase.

This is especially true in Dalmatia, where – unlike Istria and Tuscany – the advantages of this form of cultivation are just being discovered.

“The advantages are multiple: it facilitates pruning, protection and harvesting,” said Šime Marcelić, an assistant professor at the University of Zadar’s department of ecology, agronomy and aquaculture. “The canopy is airy and sunny. The fruits ripen more evenly.”

The type of pruning involves trimming excess branches on trees between 80 and 120centimeters high with three to four primary branches. This creates a smaller fertilization area suitable for a grove density of six to seven meters.

Traditional olive tree pruning results in a free-growing form; the inside of the crown dies and does not sprout its reproductive elements. Instead, these crucial parts of the tree grow on the tips of higher branches.

Over time, an “olive rainforest” is created when the highest branches of the trees start to intertwine.

In Northern Dalmatia, apart from a few exceptions, the polyconic vase is not used, even in newer plantations.

However, this is starting to change and has been spurred on by a recent demonstration and workshop held by the Association of Olive Growers of Zadar County.

Among the experts is the young agronomist Stjepan Dević, 29, from Sukošan near Zadar.

“I am grateful to Marcelić,” Dević said. “He taught me pruning and made me fall in love with olive trees.”

After completing his undergraduate studies at the University of Zadar, he worked for a few years before returning to get his Master’s degree in agrotechnical sciences.

Five years ago, he founded an olive grove with 300 trees on his grandfather’s property in Sukošan. He also bought an old olive grove with about 40 Oblica trees, which he grafted onto Oštrica, Puljka and other native varieties. “It was a miracle; they reproduced like crazy,” he said without hiding his satisfaction.

Dević also became a certified taster, started working in horticulture, and officially registered his landscape management business, Hortus Agro, in 2022.

Along with providing advice, his main job is arranging and maintaining gardens around tourist villas and facilities. “When the pruning of the olive trees is finished, I throw myself into the gardens,” he said.

According to Dević, a polyconic vase creates the best possible ratio of wood to leaf mass. He and Družijanić are pruning 120 trees in the grove into a polyconic vase.

“If the pruning of one tree takes more than 15minutes, it means that something is being done incorrectly,” said Družijanić, a student at the University of Zadar. More