In order to overcome constrains that affect olive groves and its socioeconomic value, new cropping practices focusing
on water use efficiency were investigated. The study was conducted in Northeast Portugal and different deficit
irrigation strategies (DIS) were investigated: regulated (RDI, 10% ETc during pit hardening and 80% ETc in the
remaining stages), sustained (SDI, 27.5% ETc), sustained usually applied by farmer (SDIAF, 21.2% ETc) and fully
irrigated (FI, 100% ETc), as control treatment. The fruit metabolites fluctuations and quality parameters were
evaluated. Using FI as reference, DIS treatments led to changes in the secondary metabolism in fruits with increased
total phenolic compounds (+11% in SDIAF), ortho-diphenols (+25 in SDI and +44% in SDIAF), and flavonoids
(+29% in RDI, +26% in SDI, +91% in SDIAF) concentrations, and higher total antioxidant capacity (+41% in SDI).
DIS treatments influenced the profile of olive fruit phenolics with changes in oleuropein (-55% in SDIAF), chlorogenic
acid and quercetin-3,4‟-di-O-glucoside (non-detected in FI), eriodictyol-7-O-glucoside (+64% in RDI and +95% in
SDI), and procyanidin A2 (+59% in RDI and -59% in SDIAF). Olive fruits from DIS treatments also showed higher fat
content (22, 29 and 24 % in RDI, SDI and SDIAF, respectively). Fruits from RDI and SDI presented lower palmitoleic
and linolenic acids, while no significant differences were observed in the concentrations of saturated, monounsaturated
and polyunsaturated fatty acids. When subject to a puncture test in a texture analyser, all DIS fruits presented higher
peel break force than FI control. This work show that DIS are essential for sustainable olive growing, as they do not
compromise the competitiveness of the sector in terms of olive production and associated quality parameters.This work was funded by the INTERACT project – “Integrative Research in Environment, Agro-
Chains and Technology”, no. NORTE-01-0145-FEDER-000017, in its line of research entitled ISAC, co-financed by the European Regional Development Fund (ERDF) through NORTE 2020 (North Regional Operational Program 2014/2020).info:eu-repo/semantics/publishedVersio
