## 3 Results
### Leaf Functionality and Tree Water Relations
#### 3.3.1 Season 2015  
At 55 DAFB, when water supply differentiation was not established yet, cumulative photoassimilation (\(\Sigma\)Pn), transpiration (\(\Sigma\)Tr) and the integral water stress (Sv) were similar among the four treatments (Figure 4; Table S1). The average air temperature (T\({}_{\rm air}\)) and vapor pressure deficit (VPD) during the measure period (9:00-17:00) were 29.9 \({}^{\circ}\)C and 2.3 kPa, respectively; the midday stem water potential was around \(-\)0.9 MPa and the average stomatal conductance was about 0.164 mol m\({}^{-2}\) s\({}^{-1}\). At 86-87 and 88 DAFB, trees were at the end of the pit hardening stage and water supply was differentiated among the four treatments. At 86 DAFB, the average VPD and air temperature were 3.5 kPa and 36.4 \({}^{\circ}\)C, respectively. A slight reduction in \(\Sigma\)Pn and \(\Sigma\)Tr were observed in S, while the water stress integral Sv was statistically lower in S and F in comparison with T and M (Figure 4; Table S1). The midday stem water potential was around \(-\)1.2 MPa in M and T and \(-\)1.5 MPa in F and S. The average gs recorded during the measure period was about 0.102 mol m\({}^{-2}\) s\({}^{-1}\) for M and T, 0.094 mol m\({}^{-2}\) s\({}^{-1}\) for F and 0.085 mol m\({}^{-2}\) s\({}^{-1}\) for S. At 87 DAFB, the average VPD was about 4.5 kPa and the air temperature recorded during the time of measure was about 37.5 \({}^{\circ}\)C. S showed the cumulative photoassimilation and transpiration to be lower than the remaining treatments (0.142 and 72.5 mol m\({}^{-2}\), respectively). The highest Sv was recorded in M (\(-\)3.6 GPa), followed by T (\(-\)7.0 GPa); F and S showed the lowest  
Figure 3: Soil water content (m\({}^{3}\) m\({}^{-3}\)) pattern recorded on the 4 treatments in 2015 (**A**) and 2016 (**B**). Horizontal dotted and continuous lines represent the field capacity (FC), the wilting point (WP) and the intervention threshold (IT), respectively.  
values of the water stress integral of about \(-\)10 GPa (Figure 4; Table S1). The midday stem water potential was \(-\)1.1, \(-\)1.25, \(-\)1.3 and \(-\)1.4 MPa in M, T, F and S, respectively, while the average gs was around 0.105 mol m\({}^{-2}\) s\({}^{-1}\) in M, T, F and 0.064 mol m\({}^{-2}\) s\({}^{-1}\) in S. At 88 DAFB, the average VPD and the air temperature of the period of measure (9:00-17:00) were 3.8 kPa and 37.1 \({}^{\circ}\)C, respectively. The highest cumulative photoassimilation was recorded on M (0.25 mol m\({}^{-2}\)), followed by T and F (0.198 and 0.188 mol m\({}^{-2}\), respectively). S revealed the lowest \(\Sigma\)Pn (0.125 mol m\({}^{-2}\)) and the same trend was observed for the cumulative transpiration (Figure 4A,B; Table S1). The average gs recorded during the period was 0.134 mol m\({}^{-2}\) s\({}^{-1}\) for M followed by T and F, with an average gs of about 0.096 mol m\({}^{-2}\) s\({}^{-1}\) and S (gs, 0.057 mol m\({}^{-2}\) s\({}^{-1}\)). M had the highest S\({}_{\Psi}\) (\(-\)2.5 GPa) followed by T (\(-\)6.7 GPa); the lowest S\({}_{\Psi}\) values were recorded in F and S with values of \(-\)14.2 and \(-\)17.2 GPa, respectively (Figure 4C). At 120 DAFB, trees were in the full fruit cell expansion stage. The average (9:00-17:00) air temperature and VPD were 33.5 \({}^{\circ}\)C and 2.5 kPa, respectively. The lowest \(\Sigma\)Pn and \(\Sigma\)Tr were recorded in S (0.166 and 48.6 mol m\({}^{-2}\), respectively) while the remaining treatments were similar (Figure 4A,B; Table S1). The same trend was observed for S\({}_{\Psi}\) reaching the lowest levels of the season (Figure 4C; Table S1). The midday stem water potential was \(-\)1.4, \(-\)1.5, \(-\)1.6 and \(-\)1.8 MPa for M, T, F and S, respectively, and the average stomatal conductance recorded within the measure period (9:00-17:00) was around 0.106 mol m\({}^{-2}\) s\({}^{-1}\) for M, T, F, and 0.066 mol m\({}^{-2}\) s\({}^{-1}\) for S.