To overcome constrains affecting olive groves, cropping practices focusing on
agronomic water use efficiency and their impact on quality parameters must be
investigated. We evaluated the response of olive trees (Olea europaea, cv. Cobrançosa)
to different water regimes, full irrigation (FI, 100% ETc) and three deficit irrigation
strategies (DIS) (regulated (RDI, irrigated with 80% of crop evapotranspiration (ETc) in
phases I and III of fruit growth and 10% of ETc in the pit hardening stage) and two
continuous sustained strategies (SDI), a conventional SDI (27.5% of ETc), and a lowfrequency
irrigation adopted by the farmer (SDIAF, 21.2% of ETc).
RESULTS
The effects of water regimes on the plant water status, photosynthetic performance,
metabolites fluctuations and fruit quality parameters were evaluated. All DIS treatments
enhanced leaf tissue density, RDI and SDI generally did not affect leaf water status and
maintained photosynthetic machinery working properly, while SDIAF treatment
impaired olive tree physiological indicators. DIS treatments maintained the levels of
primary metabolites in leaves, but SDIAF plants showed signs of oxidative stress.
Moreover, DIS treatments led to changes in the secondary metabolism, both in leaves
and in fruits, with increased total phenolic compounds, ortho-diphenols, and flavonoids
concentrations, and higher total antioxidant capacity, as well higher oil content.
Phenolic profiles showed the relevance of an early harvest in order to obtain higher
oleuropein levels with associated higher health benefits.
CONCLUSION
Adequate DIS are essential for sustainable olive growing, as they enhance the
competitiveness of the sector in terms of olive production and associated quality
parameters.info:eu-repo/semantics/publishedVersio