Articles
Sap flow measurements in olive trees (Olea europaea L.) cultivar ‘Menara’ under regulated and sustained deficit irrigation strategies
Article number
1419_1
Pages
1 – 10
Language
English
Abstract
The aim of this study is to evaluate the effect of sustained deficit irrigation (SDI) and regulated deficit irrigation (RDI) strategies on measured sap flow.
In this regard, measurements of sap flow were carried out in 2022 in the field on 12 year-old olive trees of ‘Menara’ cultivar at INRA Marrakech, Morocco.
Thermal dissipation probe method was used for sap flow measurements.
The irrigation regimes were studied according to the sensitivity of phenological phases to water stress with ‘Sensitive Period (SP)’ and ‘Normal Period (NP)’. The control treatment (T0) was fully irrigated (100% evapotranspiration (ETc)) throughout the season.
For RDI strategies, four water regimes were tested: T1 (SP 100% and NP 70% ETc), T2 (SP 100% and NP 60% ETc), T3 (SP 80% and NP 70% ETc), T4 (SP 80% and NP 60% ETc). For SDI strategies, a constant volume of water that is less than ETc during the entire irrigation season was evaluated: T5 (70% ETc) and T6 (60% ETc). In this study, an analysis was undertaken to investigate sap flow, stomatal conductance, and the correlations between sap flow and reference evapotranspiration (ET0) across various irrigation treatments.
The results showed that sap flow values were affected by deficit irrigation treatments and climate demand.
Higher diurnal sap flow rates were recorded in the olive trees under control (T0) compared to those under the water-stressed treatment conditions.
Water availability noticeably influenced measured stomatal conductance.
Diurnal sap flow and stomatal conductance were significantly lower in the SDI strategies, especially for T6 treatment.
High correlations and polynomial relationships were found between sap flow measurements and ET0, particularly in the control (T0) and RDI treatments (T1, T2, T3 and T4) with R2=0.71, 0.68, 0.83, 0.81, and 0.75, respectively.
However, SDI treatments (T5 and T6) showed low correlations with R2=0.38 and 0.37. The results of the sap flow measurements describe water use by olive trees monitored under various irrigation treatments, highlighting that the RDI strategies can lead to significant water savings.
In this regard, measurements of sap flow were carried out in 2022 in the field on 12 year-old olive trees of ‘Menara’ cultivar at INRA Marrakech, Morocco.
Thermal dissipation probe method was used for sap flow measurements.
The irrigation regimes were studied according to the sensitivity of phenological phases to water stress with ‘Sensitive Period (SP)’ and ‘Normal Period (NP)’. The control treatment (T0) was fully irrigated (100% evapotranspiration (ETc)) throughout the season.
For RDI strategies, four water regimes were tested: T1 (SP 100% and NP 70% ETc), T2 (SP 100% and NP 60% ETc), T3 (SP 80% and NP 70% ETc), T4 (SP 80% and NP 60% ETc). For SDI strategies, a constant volume of water that is less than ETc during the entire irrigation season was evaluated: T5 (70% ETc) and T6 (60% ETc). In this study, an analysis was undertaken to investigate sap flow, stomatal conductance, and the correlations between sap flow and reference evapotranspiration (ET0) across various irrigation treatments.
The results showed that sap flow values were affected by deficit irrigation treatments and climate demand.
Higher diurnal sap flow rates were recorded in the olive trees under control (T0) compared to those under the water-stressed treatment conditions.
Water availability noticeably influenced measured stomatal conductance.
Diurnal sap flow and stomatal conductance were significantly lower in the SDI strategies, especially for T6 treatment.
High correlations and polynomial relationships were found between sap flow measurements and ET0, particularly in the control (T0) and RDI treatments (T1, T2, T3 and T4) with R2=0.71, 0.68, 0.83, 0.81, and 0.75, respectively.
However, SDI treatments (T5 and T6) showed low correlations with R2=0.38 and 0.37. The results of the sap flow measurements describe water use by olive trees monitored under various irrigation treatments, highlighting that the RDI strategies can lead to significant water savings.
Publication
Authors
I. Khaoula, S. Er-Raki, A. Bouizgaren, R. Hadria
Keywords
olive tree, sap flow, regulated and sustained deficit irrigation
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