Estimation of stomatal conductance by infra-red thermometry in citrus trees cultivated under regulated deficit irrigation and reclaimed water

Ana Belén Mira García, Cristina Romero-Trigueros, José María Bayona Gambín, Ma del Puerto Sánchez Iglesias, Pedro Antonio Nortes Tortosa and Emilio Nicolás Nicolás

Agricultural Water Management, 2023, vol. 276, issue C

Abstract: The aim of this study was to evaluate the robustness of infra-red thermometry to estimate stomatal conductance (gs) in grapefruit trees. For this purpose, the ability of several thermal indices to determine gs was tested for different: (i) irrigation strategies: full irrigation (FI) and regulated deficit irrigation (RDI), (ii) water sources: transfer water (TW) -optimal for agricultural uses- and saline reclaimed water (RW) and (iii) phenological stages: flowering-sprouting (FS) and fruit growth (FG). During two growing seasons, measurements of gs and canopy temperature (Tc) were taken in 14-year-old ´Star Ruby´ grapefruit trees (Citrus paradisi Macf.,). Air temperature (Ta) was also recorded and then the derived thermal indices: Tc-Ta, and CWSI (crop water stress index) were calculated. Subsequently, thermal-gs correlations were established at different averaged thermal data intervals, and VPD (vapour pressure deficit) and PAR (photosynthetically active radiation) conditions. The results indicated that both, water quality and deficit irrigation, affected negatively gs and Tc during FG. In addition, the highest r2 values in thermal indices-gs correlations were found when i) the thermal data was averaged 60 min before the gs measurement, ii) gs was measured over a wide range of VPD (between 0 and 3.5 kPa), and iii) PAR was 1200 µmol m−2 s−1. The ability of the thermal indices to estimate gs improved under RDI and RW conditions, when compared to the control treatment (TW-FI). Moreover, the thermal indices that more accurately estimated gs were Tc-Ta and CWSI in FS (P < 0.001), and the absolute values of Tc in FG (P < 0.001). Overall, thermal indices obtained by infra-red sensors could be a useful tool to estimate gs in grapefruit trees. However, irrigation treatment, water quality, tree phenological stage and environmental conditions (VPD and PAR) must be considered when interpreting thermal indices-gs correlations.

Keywords: Grapefruit; Leaf temperature; Thermal indices; Water status (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0378377422006047
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:agiwat:v:276:y:2023:i:c:s0378377422006047

DOI: 10.1016/j.agwat.2022.108057

Access Statistics for this article

Agricultural Water Management is currently edited by B.E. Clothier, W. Dierickx, J. Oster and D. Wichelns

More articles in Agricultural Water Management from Elsevier
Bibliographic data for series maintained by Catherine Liu ().