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Advisor(s)
Abstract(s)
The response of grape berry metabolism to vine water
status was investigated in field grown grapevines (Vitis
vinifera cv. Castelão) in southern Portugal. Water was supplied
as: full irrigation (FI), to minimum water deficit corresponding
to 100 % of crop evapotranspiration (Etc), partial
rootzone drying (PRD) and deficit irrigation (DI), both
corresponding to an irrigation amount of 50 % Etc, and a
rainfed, i.e. no irrigation treatment (NI). In PRD, water was
supplied to one side of the root system during each irrigation
period, alternating sides every 15 d approximately.
During the growing period, PRD and DI vines showed intermediate
pre-dawn leaf water potential (Ψpd) values
(around -0.4 MPa) by the end of the growing season, FI
vines -0.2 MPa and NI -0.8 MPa. Berry weight as well as
the content of glucose and fructose per berry increased in
irrigated vines (PRD, DI, and FI) compared to NI vines. Although
both malic and tartaric acid declined in non-irrigated
vines, there was no significant difference between
treatments at harvest. The activities of invertase, malate
dehydrogenase and malic enzyme were not affected by irrigation
throughout the ripening process. The contribution
of other factors involved in the reduction of sugars and
organic acids in berries of non-irrigated vines are discussed.
These results show that deficit irrigation, like PRD
and DI, do not have any negative impact on growth and quality
of grape berries compared to fully irrigated vines, but
may result in improved berry quality compared to rainfed
vines.
Description
Keywords
Berry Deficit irrigation Invertase Malic enzyme Partial rootzone drying Vitis vinifera
Citation
Vitis, 44 (3), 103-109
Publisher
Bundesanstalt fur Zuechtungsforschung an Kulturpflanzen