## 3 Results and Discussion  
### Influence of Deficit Irrigation on Fruit Quality  
Blueberry plants are generally irrigated and are very rarely subjected to conditions of water stress [34]. However, in areas where water resources are already scarce or threatened, such as the Dorana National Park (Southwest Spain), where this research was performed, water deficit irrigation (DI) technique has been proposed as a potential alternative. Based on our results, the quality of the blueberry fruits under a deficit irrigation regime did not appear to be impaired (Table 1). The only significant difference obtained after statistical treatment was related to fruit firmness. In our case, the blueberries collected under the deficit irrigation regime (80% ETc) presented an increase in the firmness values, a parameter impacting positively on the post-harvest life of the fruits (transportation, conservation and shelf-life). These results are in accordance with other studies reporting similar results in strawberry fruits [35].  
In our study, berry weight and size were unaffected by irrigation and this fact was consistent in both sampling years and in all the studied cultivars (Table 1). In the literature, we can find controversial results regarding those parameters. Some authors showed that deficit irrigation has been associated with a reduction in berry size and weight in blueberry [36], and some others observed that an increase in the water supply reduced the fruit firmness and increased fruit size [37]. In this sense, other studies suggested that changes in firmness resulting from increases in irrigation were not always associated with changes in fruit size [20; 38].  
In general, the three cultivars analyzed in this study showed a low susceptibility to the deficit irrigation applied.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline  & **SSC** & **TA** & **pH** & **Firmness** & **h\({}^{\circ}\)** & **C\({}^{\ast}\)** & **L\({}^{\ast}\)** & **Weight** & **Size** \\ \hline \multicolumn{1}{c}{**Variety**} & & & & & & & & & \\ 'Rocio’ & 14.77 a & 0.52 a & 3.62 c & 1.62 c & 279.6 a & 4.55 c & 30.75 c & 2.09 b & 15.05 c \\ V2 & 13.65 b & 0.42 b & 3.77 b & 1.97 a & 268.4 c & 5.71 a & 35.40 a & 2.27 b & 15.84 b \\ V3 & 12.89 c & 0.35 c & 3.99 a & 1.84 b & 271.8 b & 4.98 b & 31.63 b & 2.79 a & 16.94 a \\
**Sampling year** & & & & & & & & & & \\ 2011 & 13.66 & 0.32 b & 4.14 a & 1.65 b & 270.5 b & 4.68 b & 32.33 b & 2.46 & 15.59 b \\
2012 & 13.88 & 0.53 a & 3.44 b & 1.96 a & 276.1a & 5.47 a & 32.95 a & 2.31 & 16.29 a \\
**Cultivation system** & & & & & & & & & \\ Open field & 12.86 b & 0.52 a & 3.62 b & 1.81 & 273.3 & 5.19 & 32.57 & 2.32 & 15.90 \\ Plastic tunnels & 14.68 a & 0.34 b & 3.97 a & 1.81 & 273.3 & 4.96 & 32.61 & 2.45 & 15.98 \\
**Irrigation regime** & & & & & & & & & \\ \(100\%\) ETc & 13.73 & 0.43 & 3.76 & 1.77 b & 272.9 & 5.14 & 32.60 & 2.40 & 15.95 \\
80\% ETc & 13.81 & 0.42 & 3.82 & 1.85 a & 273.6 & 5.02 & 32.50 & 2.37 & 15.93 \\ \hline \multicolumn{1}{c}{**Variety (V)**} & ****** & **** & **** & ** & ** & ** & ** & ** & ** \\ \multicolumn{1}{c}{**Sampling year (SY)**} & ns & **** & ** & ** & ** & ** & ** & ** & ** & ** \\ \multicolumn{1}{c}{**Cultivation system (CS)**} & **** & ** & ** & & & & & & & \\ \multicolumn{1}{c}{**Irrigation regime (IR)**} & ns & ns & ns & ** & ns & ns & ns & ns & ns \\ \multicolumn{1}{c}{**V x SY**} & **** & ** & ** & & ns & ** & & & & \\ \multicolumn{1}{c}{**V x CS**} & ** & ** & & & ns & ns & ** & & & \\ \multicolumn{1}{c}{**V x IR**} & ns & ns & ns & ns & ns & ns & ns & ns & ns \\ \multicolumn{1}{c}{**SY x CS**} & ** & ns & & ns & ns & ns & ns & ns & ns & \\ \multicolumn{1}{c}{**SY x IR**} & ns & ns & ns & ns & ns & ns & ns & ns & ns \\ \multicolumn{1}{c}{**CS x IR**} & ns & ns & ns & ns & ns & ns & ns & ns & ns \\ \hline \multicolumn{1}{c}{Different letters indicate significant differences by LSD (Fisher’s Least Significant Difference) test. *, **, **, **, **} & & & ns— & & ns— & & ns— & & ns— &