Qualitative and quantitative aspects of olive production in relation to climate in southern Italy

We considered here olive production according to the main relationships between the quantitative (fruit production) and qualitative (oil quality) data and the meteorological parameters through the annual season. We carried out pollen monitoring analyses over a 12-year period, to initially define the main dynamics of pollen release into the atmosphere in a typical olive production area in southern Italy (Fasano, Puglia). Pollen release was generally determined by the meteorological factors in the period before flowering, with effects on both pollen amounts and timing of flowering (early or delayed). The interactions between these pollen and meteorological parameters were investigated using principal component analysis. This revealed clusters of independent variables during the biological cycle of the olive that highlighted the relationships between annual pollen production and future fruit production, with a high degree of interaction between environmental factors and final olive oil quality. This led us to search for statistical relationships between quality parameters of the oil (acidity, oxidative degree, fatty-acid composition) and meteorological parameters (mean monthly temperatures, rainfall, humidity, winds, solar radiation, evapotranspiration during post-flowering/pre-harvest). The water stress, as defined by the potential evapotranspiration, has a large influence on acidity and fatty-acid content of the olive oil produced. These data thus provide further support of the need for quality irrigation in olive production.

► The study evidenced the olive production processes in relation to the climate trends.
► Interactions emerged between meteo-biological variables and the olive production.
► Earlier flowering and high pollen emission have positive effects on the production.
► Water stress influenced the free acidity as well as the fatty acids and their ratios.
► Water requirements during flowering, setting and the initial growth of the fruit.