Advice given as olive harvest underway in France

Each region and department has different varieties of olive, including the “Caillette” in the Alpes-Maritimes; the “Grossane” in the Baux-de-Provence valley; and the “Verdale de Carpentras”, “Lucques” and “Tanche” varieties in the Vaucluse (all Provence-Alpes-Côte d'Azur), according to news source FranceInfo.

The “Picholine”' variety, however, is common almost everywhere, especially in olive groves in the south of the country, and in Corsica.

The best time to pick can range from late August through to November, depending on region and variety.

One litre of oil

The yield from a crop of olives - how many olives it takes to make one litre of oil - depends on the time of the harvest, according to farmer Mickael Guibert, who has given some helpful harvest advice.

Mr Guibert, who manages the 996-tree olive grove Domaine des Andéols, in the Vaucluse, told FranceInfo: “It all depends if the harvest is done before the frost arrives or not. When the olive has not had frost, it still contains water. So then, you would need seven kilos [of olives] to make one litre of oil.

“[But] once the olive has been frosted over, you only need five or six kilos [of olives] to produce one litre.”

Post-harvest care

Once the olives have been picked, it is important to prune the trees at the end of winter, to improve their fruit production in future seasons.

The pruned trees should then be treated with special, natural spray, to protect them from smoke and fumes, and also to prevent a possible tree fungal disease known as “peacock eye” or “peacock spot” (oeil de paon in French).

Cyclonium or peacock spot damage to olive tree leaves (Photo: Eric Coffinet / Wikimedia Commons / Public Domain)

If any larger branches require removal, they should be tipped with sealant to prevent any viruses or fungi from attacking the tree, and to also discourage ants, who may otherwise set up home in the tree.

Mr Guibert said: “Recently, I had a case where I was pruning an olive tree, and I felt little insects on my forearm, and I saw ants. So strange. When I cut the branch, I realised that they were completely tucked inside the tree. They had got in through an old, damaged branch.

“I finally understood why one side of the tree had dry branches, and the other side was healthy. So therefore, when you take off a branch - especially a large or old one - do not forget to put sealant on the cut.”

The team also advises harvesters to lightly rake the ground around the olive trees. Rather than completely digging up the ground, it is better to rake the more shallow earth.

This will air it out, and get rid of any undesirable plants or weeds that could be near the tree roots, Mr Guibert said.