Mario Apicella staggers down a steep flight of stone steps on Italy's Amalfi Coast, sweat dripping off his nose.
On the 66-year-old's back is a huge plastic crate, packed to the brim with freshly picked, bright yellow Amalfi lemons.
The effort of hauling these 57kg loads from the high terraces to a small fleet of pick-up trucks is a key element of a farming practice that has sculpted the area's unique landscape.
Over the centuries, thousands of lemon trees were planted on terraces carved into the mountainsides that plunge down to the cobalt blue waters of the Mediterranean.
The men who harvest them are nicknamed "contadini volanti", or "flying farmers", because of the vertiginous slopes that they must clamber up and down.
But the landscape - feted by the likes of DH Lawrence, John Steinbeck and Gore Vidal - is now under threat, with competition from cheaper, less aromatic lemons from abroad driving prices down and forcing Amalfi's farmers to abandon terraces that their families have cultivated for generations.
The abandonment of the terraces leads in turn to the collapse of dry stone walls and a dramatic increase in the risk of landslides and erosion - which can be fatal along a coastline where villages sit in narrow, V-shaped valleys where mud and water are funneled to devastating effect.
A group of Italy's foremost geologists convened on the Amalfi Coast last month to warn of the extreme perils that the region faces as a result of the decline of lemon cultivation.
They said that successive governments had done "virtually nothing" to prevent landslides and erosion, despite the fact that such risks were higher in Italy than in any other European country because of its topography.
The geologists gave alarming assessments of the risk of landslides along the 50km stretch of coastline: 88 per cent for the town of Amalfi, the former maritime trading republic which lends its name to the whole coast, 77 per cent for nearby Minori and 88 per cent for neighbouring Maiori.
"You see that pink house up there on the hillside? All those terraces around it have been abandoned," said Salvatore Aceto, who represents the sixth generation of his family to grow lemons on the terraces that overlook the picturesque village of Amalfi.
"That could easily cause a disaster. The dry-stone walls will collapse if they are not maintained. Then you have a big problem."
The custodians of this World Heritage-listed landscape, which attracts hordes of tourists every summer, are slowly dying out. The number of lemon farmers has dwindled to around 320, and their average age is 60.
They are not being replaced by their sons and grandsons, who regard the work as too tough and too poorly paid. The slopes are too steep for roads to be built, and even mules struggle to access most of the tiny terraces on which the lemon trees grow.
The men labour from 7am until late afternoon, sometimes doing 20 or 30 runs up and down the mountain. They are paid €6 for each crate they deliver.
"Young people prefer to work in tourism, as waiters or cooks. It's a much easier life," said Apicella. After 30 years of harvesting lemons, he is ready for retirement next year.
The risk of mudslides, already heightened by the abandonment of the lemon terraces, has been made worse by changing weather patterns.
"We're experiencing much more intense, more violent storms where a large amount of rain falls all at once," said Andrea Reale, Mayor of Minori.
He wants to install ground sensors and remote-controlled cameras in the hills to monitor the risk and provide an early warning system for the 800 families who live in the town.
"If it works well here, then it could be a test case. It could be applied to the rest of the Amalfi Coast and to other areas of Italy that are at risk from erosion, like the Cinque Terre in Liguria," he said from his office overlooking a cobbled piazza.
Aceto worked as an accountant before his father, now 81, persuaded him to return to the family business three years ago.
"I was wealthy. I wore Armani suits, I had a gold watch. But I wasn't happy. I sat in front of a computer all day. Then I changed my life. When I came here I was overweight, but I lost 18kg in six months. I was reborn."
"My dream is to keep it going for the next generation, and the one after that," said Mr Aceto. "But this is not normal farming. It's vertical farming."