These results confirm that the application of deficit irrigation (T1) contributes to an increase in overall product quality. Furthermore, Pistacia atlantica rootstock provided better yield and quality than the other rootstocks studied.

Irrigation scheduling of fruit trees according to water balance provided significant differences between locations. In recent years, water status measurements such as water potential have been suggested as irrigation tools in different fruit trees. The aim of this study was to adjust water potential threshold values previously studied and water application approaches that permit the irrigation scheduling of olive trees based on midday stem water potential. The experiments were performed during three seasons (from 2005 to 2007) in two different locations (Badajoz and Ciudad Real) with different weather and cultural conditions. In both locations, the olive orchards were seven years old at the beginning of the experiment but had significantly different canopy development. In Ciudad Real the canopy shaded area at the beginning of the experiment was 15% and the first crop was harvested in 2003. On the other hand, canopy shaded area of the olive orchard in Badajoz experiment was 40% and the first crop was harvested in 2001. Therefore, we assimilated Ciudad Real orchard as young, while Badajoz was mature. Three different irrigation treatments were compared in both locations: Control treatment with traditional water balance as irrigation scheduling and two treatments in which midday stem water potential (SWP) provided the information about water management. In the midday water stem potential irrigation (WI) the threshold value of SWP was -1.2 MPa before the beginning of the massive pit hardening period and -1.4 after this date. Finally, in the deficit treatment (DI) the threshold value of SWP was -2.0 MPa throughout the season. In WI and DI treatment irrigation was applied when SWP reached the threshold value. No significant differences were found between Control and WI in any of the seasons and locations when water potential, leaf conductance, shoot and fruit growth and yield (fruit and oil) were considered. In both locations, the same SWP value in WI treatment produced similar water application as the Control treatment. In DI treatment, shoot growth was significantly reduced in both locations in all the seasons. The SWP in DI trees was clearly affected in both locations, while leaf conductance was only reduced in the Badajoz experiment. In the Ciudad Real experiment no significant differences were found in fruit growth, whereas differences were found in Badajoz. However, yield was significantly reduced in Ciudad Real, but not in Badajoz. WI treatment was successful for no water stress conditions. On the other hand, DI treatment was a mild water stress treatment which reduced yield only in low covert orchard, but not in the ones with almost maximum canopy shaded area. Our work presents an approach for using midday stem water potential in the irrigation scheduling of olive trees. The experiments were performed in two different locations and during three years, in order to establish the usefulness of this approach. The results support that the threshold values suggested for no water stress conditions are the s...

Please cite this article in press as: Galindo, A., et al., Deficit irrigation and emerging fruit crops as a strategy to save water in Mediterranean semiarid agrosystems. Agric. Water Manage. (2017) b s t r a c tWater scarcity in Mediterranean climate areas will be progressively aggravated by climate change, population increase and urban, tourism and industrial activities. To protect water resources and their integrity for future use and to improve biodiversity, besides following advanced deficit irrigation strategies in fruit cultivation, attention could well be directed towards what are at present underused plant materials able to withstand deficit irrigation with minimum impact on yield and fruit quality. To this end, the state of the art as regards deficit irrigation strategies and the response of some very interesting emerging fruit crops [jujube (Zizyphus jujuba Mill.), loquat (Eriobotrya japonica Lindl.), pistachio (Pistacia vera L.) and pomegranate (Punica granatum L.)] are reviewed. The strengths and weaknesses of deficit irrigation strategies and the mechanisms developed by these emerging fruit crops in the face of water stress are discussed. The response of these crops to deficit irrigation, with special attention paid to the effect on yield but also on fruit quality and health-related chemical compounds, was analysed in order to assess their suitability for saving water in Mediterranean semiarid agrosystems and to analyze their potential role as alternatives to currently cultivated fruit crops with higher water requirements. Finally, the factors involved in establishing an identity brand (hydroSOS) to protect fruits obtained under specific DI conditions are discussed.

Fruits and vegetables cultivated under controlled deficit irrigation (CDI) are called hydrosustainable (hydroSOS) products and have its own personality and are environmentally-friendly. Focus groups helped in classifying key farming, sensory, and health concepts associated with CDI-grown pistachios. Besides, focus groups also helped in stating that a logo was needed for these special foods, and that a hydroSOS index is also essential to certify that the products have been controlled by a control board. Conjoint analysis was used to check which attributes could be helpful in promoting CDI-grown pistachios among Spanish consumers in a 1st step toward the European Union (EU) market. It was clearly proved that the main silo of properties driving the attention of Spanish consumers was that related to health. The most important attributes for pistachios were "product of Spain," "rich in antioxidant," and "crunchy"; this finding was clearly related to the popularity of regional foods, the preoccupation of European consumers for their health, and the joy related to the crunchiness of toasted nuts, respectively. The use of these 3 concepts, together with the use of the hydroSOS logo, will be essential to promote hydroSOS pistachios among Spanish and EU consumers. Finally, it is important to highlight that in general Spanish consumers were willing to pay an extra amount of 1.0 euros per kg of hydroSOS pistachios. These earnings will be essential to convince Spanish farmers to implement CDI strategies and have a sustainable and environmental-friendly use of the irrigation water.

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