Improving performance of olive trees by the enhancement of key physiological parameters of olive leaves in response to foliar fertilization

Temporal Variation of Phenolic and Mineral Composition in Olive Leaves Is Cultivar Dependent

“…Beside phenols, which are common constituents of various plant species, olive phenols include the group of secoiridoids, which are exclusive for the Oleaceae family [ 4 ]. Secoiridoids such as oleuropein and its precursor hydroxytyrosol are considered the main phenolic compounds in OL [ 6 ] with proven anticarcinogenic, anti-inflammatory, and antimicrobial properties [ 7 , 8 ]. Besides them, other relatively abundant phenols in OL are flavone-7-glucosides of luteolin and apigenin, as well as verbascoside, which is a conjugated glucoside of hydroxytyrosol and caffeic acid [ 6 ].…”

Manganese soil and foliar fertilization of olive plantlets: the effect on leaf mineral and phenolic content and root mycorrhizal colonization

“…Olive leaves with a higher oleuropein content may be linked to multiple benefits for olive growers. It can be used for olive oil enrichment or have crucial importance for olive sustainable growing in that oleuropein has a specific role in plant protection and resistance against herbivores and pathogens . Also, it has been suggested that oleuropein rich extracts suppress olive oil deterioration and also may have a positive influence on consumer health benefits and the shelf life of food products …”

“…Leccino . Although olive oil is in the main focus of olive research, in recent years, the attention of researchers has focused on olive leaves as a valuable source of phytochemicals such as polyphenols, which in turn have a positive impact on human health …”

“…It has been suggested that fertilization may have an impact on the plant phenolic profile; however, only a few studies have focused on investigating the effects of mineral nutrition on the phenolic profile of olive leaves . To date, the majority of multi‐nutrient fertilization studies on olive trees have been conducted where Mn was just one of the main constituents in fertilizers . Manganese ions ensure the functioning of phenylalanine ammonia lyase and may have a profound effect on the biosynthesis of plant phenolics .…”

“…6 To date, the majority of multi-nutrient fertilization studies on olive trees have been conducted where Mn was just one of the main constituents in fertilizers. 2,7 Manganese ions ensure the functioning of phenylalanine ammonia lyase and may have a profound effect on the biosynthesis of plant phenolics. 8 In alkaline, calcareous soil, the presence of CaCO 3 affects the availability of soil nutrients.…”