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Deficit irrigation scheduling needs accurate indicators and in recent decades, continuous plant indicators have been developed. However, threshold values that could be useful in commercial orchards are not commonly reported. The water potential is a discontinuous measurement commonly used as a reference in the description of water stress level. In some fruit trees, such as olive trees, there are several works suggesting threshold values in fully irrigated conditions, but the influence of the evaporative demand is not taken into account. The aim of this work is to compare the values of the fully irrigated water potential in different locations in order to study the estimation of a common baseline. Three mature olive orchards were selected, two in Seville (South Spain) and one in Ciudad Real (Central Spain). There were clear differences between the three orchards during the 2015 season. Orchards in Seville (S-1 and S-2) were close (10 km apart) and had the same cultivar (table olive, cv Manzanilla) but they were different in terms of the fruit load (almost no fruit in S-1, medium fruit load in S-2) and distribution of water (single drip line in S-1, double drip line in S-2). The orchard in Ciudad Real (CR) was very different with regards to the olive cultivar (cv Cornicabra) and the location, as it was in a borderline zone for olives growing with very low temperatures that delay the phenological development. In all the orchards, the best baseline was obtained with different climatic measurements, even in S-1 and S-2. When all the data were considered,the best fit was obtained with the average vapour pressure deficit (VPDav). Influence of the location was significant in the interception term of the equations when Temperature was used but not with VPD. This source of variation was reltade with the level of fruit load. Slope of the equations was not affected for the location. The equation obtained was validated with water potential data from previous seasons ofS-1 and CR

The fruit maturation stage is considered the optimal phenological stage for implementing water deficitin jujube (Zizyphus jujuba Mill.), since a low, moderate or severe water deficit at this time has no effect onyield, fruit volume or eating quality. However, no information exists at fruit water relations level on themechanisms developed by Z. jujuba to confront drought. The purpose of the present study was to increaseour understanding of the relationship between leaf and fruit water relations of jujube plants under dif-ferent irrigation conditions during fruit maturation, paying special attention to analysing whether fruitsize depends on fruit turgor. For this, adult jujube trees (cv. Grande de Albatera) were subjected to fiveirrigation treatments. Control plants (T0) were irrigated daily above their crop water requirements inorder to attain non-limiting soil water conditions in 2012 and 2013. T1 plants were subjected to deficitirrigation throughout the 2012 season, according to the criteria frequently used by the growers in thearea. T2 (2012), T3 and T4 (2013) were irrigated as T0 except during fruit maturation, in which irrigationwas withheld for 32, 17 and 24 days, respectively. The results indicated that the jujube fruit maturationperiod was clearly sensitive to water deficit. During most of this stage water could enter the fruits viathe phloem rather than via the xylem. From the beginning of water withholding to when maximumwater stress levels were achieved, fruit and leaf turgor were maintained in plants under water deficit.However, a direct relation between turgor and fruit size was not found in jujube fruits, which could bedue to an enhancement of a cell elasticity mechanism (elastic adjustment) which maintains fruit turgorby reducing fruit cells size or to the fact that jujube fruit growth depends on the fruit growth-effectiveturgor rather than just turgor pressure.

Deficit irrigation scheduling needs accurate indicators and in recent decades, continuous plant indicators have been developed. However, threshold values that could be useful in commercial orchards are not commonly reported. The water potential is a discontinuous measurement commonly used as a reference in the description of water stress level. In some fruit trees, such as olive trees, there are several works suggesting threshold values in fully irrigated conditions, but the influence of the evaporative demand is not taken into account. The aim of this work is to compare the values of the fully irrigated water potential in different locations in order to study the estimation of a common baseline. Three mature olive orchards were selected, two in Seville (South Spain) and one in Ciudad Real (Central Spain). There were clear differences between the three orchards during the 2015 season. Orchards in Seville (S-1 and S-2) were close (10 km apart) and had the same cultivar (table olive, cv Manzanilla) but they were different in terms of the fruit load (almost no fruit in S-1, medium fruit load in S-2) and distribution of water (single drip line in S-1, double drip line in S-2). The orchard in Ciudad Real (CR) was very different with regards to the olive cultivar (cv Cornicabra) and the location, as it was in a borderline zone for olives growing with very low temperatures that delay the phenological development. In all the orchards, the best baseline was obtained with different climatic measurements, even in S-1 and S-2. When all the data were considered,the best fit was obtained with the average vapour pressure deficit (VPDav). Influence of the location was significant in the interception term of the equations when Temperature was used but not with VPD. This source of variation was reltade with the level of fruit load. Slope of the equations was not affected for the location. The equation obtained was validated with water potential data from previous seasons ofS-1 and CR

The fruit maturation stage is considered the optimal phenological stage for implementing water deficitin jujube (Zizyphus jujuba Mill.), since a low, moderate or severe water deficit at this time has no effect onyield, fruit volume or eating quality. However, no information exists at fruit water relations level on themechanisms developed by Z. jujuba to confront drought. The purpose of the present study was to increaseour understanding of the relationship between leaf and fruit water relations of jujube plants under dif-ferent irrigation conditions during fruit maturation, paying special attention to analysing whether fruitsize depends on fruit turgor. For this, adult jujube trees (cv. Grande de Albatera) were subjected to fiveirrigation treatments. Control plants (T0) were irrigated daily above their crop water requirements inorder to attain non-limiting soil water conditions in 2012 and 2013. T1 plants were subjected to deficitirrigation throughout the 2012 season, according to the criteria frequently used by the growers in thearea. T2 (2012), T3 and T4 (2013) were irrigated as T0 except during fruit maturation, in which irrigationwas withheld for 32, 17 and 24 days, respectively. The results indicated that the jujube fruit maturationperiod was clearly sensitive to water deficit. During most of this stage water could enter the fruits viathe phloem rather than via the xylem. From the beginning of water withholding to when maximumwater stress levels were achieved, fruit and leaf turgor were maintained in plants under water deficit.However, a direct relation between turgor and fruit size was not found in jujube fruits, which could bedue to an enhancement of a cell elasticity mechanism (elastic adjustment) which maintains fruit turgorby reducing fruit cells size or to the fact that jujube fruit growth depends on the fruit growth-effectiveturgor rather than just turgor pressure.