## 3 Results  
The number of nuts per branchlet was not affected by the water status, as shown in Table 1. Contrarily, we found a significant yearly variation. In 2015, the number of nuts per branchlet was 60% higher than the previous year (28.2 and 61.5 in 2014 and 2015, respectively). Irrigation had no effect on the other measured parameters (fresh and dry weight of nuts and kernels), as shown in Table 1. Differences between years were also significant for these parameters. In 2015 we found a significantly lower fresh and dry weight of both nuts and kernels (38 and 60% less in nuts and 18 and 16% less in kernels, respectively). The cumulated water stress level had a positive and significant influence on chlorophylls content, as shown in Table 2. Less stressed trees (level 0) showed significantly higher values of chlorophylls compared with the more stressed ones (level 2) (14.7 compared to 9.3 mg/100 g for chlorophyll a, 21.1 compared to 11.5 mg/100 g for chlorophyll b and 35.5 compared to 21 mg/100 g for total chlorophyll, respectively). No differences in chlorophylls content were found between years. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Main Factors** & **Nuts/Branchlet (n\({}^{\circ}\))** & **Nut F.W. (g)** & **Kernel F.W. (g)** & **Nut D.W. (g)** & **Kernel D.W. (g)** \\ \hline
**Stress Level** & & & & \\
0 & \(38.5\pm 5.59\)\({}^{\mathrm{ns}}\) & \(2.2\pm 0.07\)\({}^{\mathrm{ns}}\) & \(0.8\pm 0.08\)\({}^{\mathrm{ns}}\) & \(1.0\pm 0.21\)\({}^{\mathrm{ns}}\) & \(0.4\pm 0.03\)\({}^{\mathrm{ns}}\) \\
1 & \(49.7\pm 7.01\) & \(2.0\pm 0.08\) & \(0.8\pm 0.11\) & \(0.8\pm 0.22\) & \(0.5\pm 0.06\) \\
2 & \(46.4\pm 7.01\) & \(2.0\pm 0.08\) & \(0.8\pm 0.13\) & \(0.8\pm 0.21\) & \(0.6\pm 0.06\) \\ \hline
**Year** & & & & \\
2014 & \(28.2\pm 5.19\)\({}^{\mathrm{***}}\) & \(2.5\pm 0.17\)\({}^{\mathrm{***}}\) & \(0.8\pm 0.08\)\({}^{\mathrm{***}}\) & \(1.2\pm 0.05\)\({}^{\mathrm{***}}\) & \(0.5\pm 0.03\)\({}^{\mathrm{***}}\) \\
2015 & \(61.5\pm 5.46\) & \(1.53\pm 0.20\) & \(0.7\pm 0.03\) & \(0.5\pm 0.08\) & \(0.41\pm 0.05\) \\ \hline
**Interaction** & & & & \\ Stress level \(\times\)Year & ns & ns & ns & ns \\ \hline \hline \end{tabular} Values are express as mean \(\pm\) SD (n = 6). Values in the same column followed by different lettersindicate significant differences (Tukey’s test \(p\leq 0.05\)); ns, not significant (\(p>0.05\)). \({}^{\mathrm{***}}\)\(p<0.001\).  
\end{table} 
Table 1: Effect of water stress levels and the year on the following biometric parameters: numbers of fruits per branchlet (n\({}^{\circ}\)), fresh weight (F.W., g) and dry weight (D.W., g) of nuts and kernels. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Main Factors** & **Chl a (mg/100 g)** & **Chl b (mg/100 g)** & **Chl tot (mg/100 g)** \\ \hline
**Stress level** & & & \\
0 & \(14.7\pm 1.81\)\({}^{\mathrm{b}}\) & \(21.1\pm 3.86\)\({}^{\mathrm{b}}\) & \(35.8\pm 5.51\)\({}^{\mathrm{b}}\) \\
1 & \(11.7\pm 1.74\)\({}^{\mathrm{ab}}\) & \(16.3\pm 3.22\)\({}^{\mathrm{ab}}\) & \(28.0\pm 4.92\)\({}^{\mathrm{ab}}\) \\
2 & \(9.3\pm 1.60\)\({}^{\mathrm{a}}\) & \(11.5\pm 3.25\)\({}^{\mathrm{a}}\) & \(21.0\pm 4.75\)\({}^{\mathrm{a}}\) \\ \hline
**Year** & & & \\
2014 & \(12.0\pm 2.73\)\({}^{\mathrm{ns}}\) & \(17.6\pm 4.93\)\({}^{\mathrm{ns}}\) & \(29.6\pm 7.64\)\({}^{\mathrm{ns}}\) \\
2015 & \(11.6\pm 3.16\) & \(14.4\pm 5.20\) & \(26.0\pm 8.65\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Effect of water stress levels and year on chlorophylls content (mg/100 g). Chl a = chlorophyll a, Chl b = chlorophyll b and Chl tot = chlorophyll total. Volatile compound composition revealed that terpenes was the major class of volatile profile. The most abundant compounds were \(\alpha\)-Pinene (ranging 26.2-35.0 \(\mu\)g/g), D-Limonene (2.8-3.3 \(\mu\)g/g), 2-Carene (1.8-3.0 \(\mu\)g/g) and \(\beta\)-Myrcene (0.6-1.4 \(\mu\)g/g) (Table 3). In addition, the volatile analysis detected alcohol, pyrroles, esters and hydrocarbons present, for a total of seventeen volatile compounds (data not shown).