Iglesias et al. (2026) Daily sap flow, leaf morphology, and stem xylem characteristics under deficit irrigation and warming during the late winter and spring in young olive trees

Identification

• Journal: Agricultural Water Management
• Year: 2026
• Date: 2026-07-16
• Authors: María Agustina Iglesias, María Cecilia Rousseaux, L. Martín Agüero Alcaras, Peter S. Searles
• DOI: 10.1016/j.agwat.2026.110628

Research Groups

• Centro Regional de Investigaciones Científicas y Transferencia Tecnol´ogica de La Rioja (CRILAR-Provincia de La Rioja-UNLaR, SEGEMAR-UNCa-CONICET)
• Departamento de Ciencias Exactas, Físicas y Naturales (DACEFyN), Universidad Nacional de La Rioja
• Agencia de Extensi´on Rural Aimogasta, Instituto Nacional de Tecnología Agropecuaria (INTA)

Short Summary

This study evaluates the combined effects of moderate deficit irrigation and warming on whole-tree daily sap flow, leaf morphological traits, and stem xylem vessel characteristics in young olive trees. The results show that warming increases tree water use over the short term, but changes in leaf area due to warming may ameliorate such increases.

Objective

• Evaluate the combined effects of moderate deficit irrigation (50%) and warming (+3–4 ◦C) on whole-tree daily sap flow, leaf morphological traits, and stem xylem vessel characteristics in young olive trees.
• Assess the impact of climate change on olive cultivation in hot, arid regions.

Study Configuration

• Spatial Scale: Field experiment conducted at a single location (CRILAR-CONICET experimental station) in Anillaco, La Rioja, Argentina.
• Temporal Scale: Late winter and spring (August to November 2019).

Methodology and Data

• Models used: Heat balance method for sap flow measurements.
• Data sources: Field measurements of sap flow, leaf morphology, and stem xylem characteristics.

Main Results

• Warming increased daily sap flow on a leaf area basis throughout the experiment.
• Moderate deficit irrigation did not decrease sap flow, although stomatal conductance (gs) and stem water potential (Ψs) decreased.
• Leaf area per tree was significantly lower under warming compared to control temperature by mid-spring.
• Stomatal density was lower in leaves from trees receiving the warming treatment.

Contributions

• This study provides new insights into the combined effects of deficit irrigation and warming on olive tree physiology, which is essential for understanding the potential impacts of climate change on olive cultivation.

Funding

• This research was funded by CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas) and INTA (Instituto Nacional de Tecnología Agropecuaria).

Citation

@article{Iglesias2026Daily,
  author = {Iglesias, María Agustina and Rousseaux, María Cecilia and Alcaras, L. Martín Agüero and Searles, Peter S.},
  title = {Daily sap flow, leaf morphology, and stem xylem characteristics under deficit irrigation and warming during the late winter and spring in young olive trees},
  journal = {Agricultural Water Management},
  year = {2026},
  doi = {10.1016/j.agwat.2026.110628},
  url = {https://doi.org/10.1016/j.agwat.2026.110628}
}