Relationships between climatic variables and sap flow, stem water potential and maximum daily trunk shrinkage in lemon trees

• Published in: Plant and soil Vol. 279; no. 1-2; pp. 229 - 242
• Main Authors: Ortuno, M.F, Garcia-Orellana, Y, Conejero, W, Ruiz-Sanchez, M.C, Mounzer, O, Alarcon, J.J, Torrecillas, A
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.01.2006; Springer Nature B.V
• Subjects: Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agronomy. Soil science and plant productions; Air temperature; Biological and medical sciences; Citrus limon; Climate change; Economic plant physiology; Evapotranspiration; Fruit trees; Fruits; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Irrigation; Irrigation scheduling; Irrigation water; Irrigation. Drainage; lemons; Moisture content; plant-water relations; Plants; Sap flow; shrinkage; Soil plant interactions; Soil water; Soil water deficit; Solar radiation; temperature; tree trunk; Tree trunks; Vapor pressure; Water potential; Water relations, transpiration, stomata; Water requirements; Biometrics; Irrigation; Sap; trunk diameter fluctuations; Horticulture; Climatic data; Citrus fruit; Rutaceae; Arboriculture; Environmental factor; Physical environment; Stem; Citrus limon; Maximum; Daily; lemon; Internal flow; Water regime; Dicotyledones; plant-water relations; Angiospermae; Water engineering; sap flow; Fruit tree; Diameter; Fluctuations; Biophysics; Shrinkage; Irrigation scheduling; Agroclimatology; Water potential; Statistical regression; Fruit crop; Plant trunk; Vegetative apparatus; Spermatophyta; Specific relation
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-005-1302-z

The feasibility of obtaining sap flow (SF), maximum daily trunk shrinkage (MDS) and midday stem water potential (Ψstem) baselines or reference values for use in irrigation scheduling was studied in adult Fino lemon trees (Citrus limon (L.) Burm. fil.) grafted on sour orange (C. aurantium L.) rootstocks. Plants were irrigated daily above their water requirements in order to obtain non-limiting soil water conditions. The results indicated that baselines for plant-based water status indicators (MDS, SF and Ψstem) can be obtained, even though there was a certain scattering of the data points representing the relations between the plant-based measurements and the environmental variables (reference evapotranspiration, solar radiation, vapour pressure deficit and temperature). SF was more closely associated with changes in the studied evaporative demand variables than were MDS and Ψstem. SF and Ψstem were more closely correlated with changes in reference evapotranspiration (ETo) (r ² = 0.93 and 0.79, respectively), while MDS behaviour was best correlated with mean daily air temperature (T m) (r ² = 0.76). Increases in the evaporative demand induced more negative Ψstem values and, as a consequence, SF increased, which, in turn, was translated into an increase in MDS. This confirmed that SF and MDS were very good predictors of the plant water status during the observation period and their continuous recording offers the promising possibility of their use in automatic irrigation scheduling in lemon trees.