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Advisor(s)
Abstract(s)
The partial root-zone drying (PRD) irrigation technique
has been proposed for viticulture as a possible way to
save water without compromising yield. Half of the plant
root system is slowly dehydrating whereas the other half is
irrigated; after about two weeks the opposite side of vines is
irrigated. A PRD irrigation system (50 % of the crop
evapotranspiration - ETc) was installed in a vineyard (Vitis
vinifera L. cv. Castelão) in Southern Portugal and compared
with two other irrigation systems, deficit irrigation,
DI (50 % ETc) and full irrigation, FI (100 % ETc), as well
as with non-irrigated vines (NI). Water was applied twice a
week, from fruit set (mid-June) until one week before harvest
(September 3). While FI vines remained well watered
during the ripening period, a severe water stress developed
in NI plants. PRD and DI vines exhibited mild water deficits
during the same period. A significant decrease in vegetative
growth (shoot weight, pruning weight, leaf layer number
and percentage of water shoots) was observed in NI and
PRD vines when compared to DI and FI. In denser canopies
(FI and DI) berry temperature was always lower than that of
the more open ones (NI and PRD). The higher degree of
cluster exposition in PRD and NI had a positive influence
on berry composition due to temperature and incident radiation,
leading to higher concentrations of anthocyanins
and total phenols in the berry skin compared to DI and FI
vines. Irrigation did not significantly affect berry sugar
accumulation and pH in berries. Compared to FI, PRD and
DI treatments water use efficiency (the amount of fruit produced
per unit of water applied) was doubled since at the
same yield the amount of water applied, was reduced by
50 %.
Description
Keywords
Berry temperature Canopy microclimate Fruit quality Vitis vinifera L. Irrigation Partial rootzone drying Yield
Citation
Vitis, 44 (3), 117-125
Publisher
Bundesanstalt fur Zuechtungsforschung an Kulturpflanzen