Changes in the profiles of mineral elements, phenols, tocopherols and soluble carbohydrates of olive fruit following foliar nutrient fertilization

The present research was accomplished on olive fruits cv. Picholine. It aimed to study the effects of nutrient fertilization on mineral elements, phenolics, tocopherols and soluble carbohydrates. The foliar applications were carried out during two successive years and included four treatments: TC (control, without foliar nutrition), T1 (rich in nitrogen, applied at the start of vegetation, 10 days later and 20 days later), T2 (rich in boron, magnesium, sulfur and manganese, applied at the beginning of flowering and 10 days later) and T3 (T1+T2). At the end of the experiment (after two experimental years), olive fruits were analyzed. This study showed that fertilization caused a significant decrease of total phenols and tocopherols contents and induced qualitative changes in the profiles of minerals, phenols, tocopherols and carbohydrates. The results elucidated an evident association between environmental concentrations of nutrients and chemical composition of olive fruits.