3. Results
3.1. Hardening period
Substrate water content values (v) in the reference treatment
(CTL-1) were close to field capacity throughoutthe irrigation cycles
(Fig. 1B).CTL-2 remainednearly stable (between34 and26%)during
the hardening period. However, the preconditioning deficit treatments of DI, PRDFIX and PRDALT averaged -v values of 27, 55 and
50% lower than CTL-1, respectively (Fig. 1B). PRDFIX exhibited a
substantial depletion in -v, averaging values of 14.3 and 10.2%, in
the wet and dry pot, respectively. This could also be observed in
the alternated irrigation in PRDALT when -v in the dry pot reached
12%. Despite of the -v differences observed, all the stress treatments (DI, PRDFIX and PRDALT) resulted in moderate vine water deficits, as indicated by the stem water potential ( s) values measured at midday (t3), which were around −0.7 MPa (Fig. 1C). Similar
to those observed in s, a sharp reduction in leaf insertion angle
(LIA) of DI, PRDFIX and PRDALT treatments were obtained, being
more pronounced in PRDFIX (Table 1). Water deficit also lowered
the predawn leaf water potential ( pd) measured at t1 (Figs. 2
A and 3 A ). However, no significant differences in leaf osmotic
potential ( o) and leaf turgor potential ( t) were found between
treatments during the hardening period (Fig. 2B and D). Only the
PRDALT significantly induced decreases in leaf osmotic potential