The changes in climate that have been affecting our whole planet for years have also created alarm among olive growers, as these are one of the most common varieties of fruit tree grown in the Mediterranean basin. The rise in temperatures, the increase in droughts and the growing frequency of extreme weather events, have all had a strong impact on olive production in the Mediterranean area, affecting both quantity and quality. In Italy, the central-southern regions have been particularly affected, with the 2022 – 2023 oil season witnessing a huge fall in production, mainly due to high temperatures in summer and autumn and a prolonged drought.
The ideal climate for olive cultivation features a warm, sunny period in summer and a cold, wet spell in winter.
In some areas of the Mediterranean, the increasing variations in climate between different years and seasons are having a significant impact on the phenology of the olive crop.
Excessive rainfall and high humidity inhibit pollination and encourage flowers and fruits to fall early.
The trend towards higher minimum temperatures in winter and in the first days of spring encourages almost constant growth, early flowering and ripening of the fruit, and an increased risk of infestation by the oil fly and other pathogens.
Although the olive tree can survive in drought conditions, a lack of water for long periods reduces the number of flowers on the plant and restricts fruit growth, leading to a decrease in production.
High temperatures can also affect the chemical composition of the olive oil, reducing the overall content of oleic acid and polyphenols, and this has a negative impact on its sensory properties and shelf life.
Certain agronomic practices have long been used to combat the effects of climate change, including protection from pests and the use of artificial irrigation. Because of the very high cost of these measures, it will become extremely important in the future to invest more in improving the genotype, by increasing the use of cultivars resistant to drought and by developing new ones.
However, we should recall that the olive tree is not just a crop in need of protection against climate change, but also a useful means of preventing the build-up of carbon dioxide in the atmosphere. Indeed, recent studies have shown the ability of an olive grove – especially when intensively cultivated – to store biomass and so to capture carbon, helping to reduce CO² emissions into the atmosphere.