Relationships Between Climatic Variables and Sap Flow, Stem Water Potential and Maximum Daily Trunk Shrinkage in Lemon Trees

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) (r2 = 0.93 and 0.79, respectively), while MDS behaviour was best correlated with mean daily air temperature (Tm) (r2 = 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.

[1]  J. Alarcón,et al.  Interpreting trunk diameter changes in young lemon trees under deficit irrigation , 2004 .

[2]  D. Remorini,et al.  Comparison of water status indicators for young peach trees , 2003, Irrigation Science.

[3]  E. Fereres,et al.  Suitability of stem diameter variations and water potential as indicators for irrigation scheduling of almond trees , 2003 .

[4]  Elias Fereres,et al.  Irrigation scheduling protocols using continuously recorded trunk diameter measurements , 2001, Irrigation Science.

[5]  R. Oren,et al.  Species differences in stomatal control of water loss at the canopy scale in a mature bottomland deciduous forest , 2003 .

[6]  Jordi Marsal,et al.  Phenology and drought affects the relationship between daily trunk shrinkage and midday stem water potential of peach trees , 2002 .

[7]  Brent Clothier,et al.  Heat-pulse measurements of sap flow in olives for automating irrigation: tests, root flow and diagnostics of water stress , 2001 .

[8]  J. Alarcón,et al.  Comparison of continuously recorded plant-based water stress indicators for young lemon trees , 2004, Plant and Soil.

[9]  J. Y. Lorendeau,et al.  Specific micromorphometric reactions of fruit trees to water stress and irrigation scheduling automation , 1992 .

[10]  R. H. Swanson,et al.  A Numerical Analysis of Heat Pulse Velocity Theory and Practice , 1981 .

[11]  Cornelis van Leeuwen,et al.  Stem Water Potential is a Sensitive Indicator of Grapevine Water Status , 2001 .

[12]  Sylvia Dayau,et al.  Significance and limits in the use of predawn leaf water potential for tree irrigation , 1999, Plant and Soil.

[13]  F. Molz,et al.  On the Mechanism of Water-Stress-Induced Stem Deformation1 , 1973 .

[14]  Joan Girona,et al.  Sensitivity of Continuous and Discrete Plant and Soil Water Status Monitoring in Peach Trees Subjected to Deficit Irrigation , 1999 .

[15]  O. Bethenod,et al.  Behavior of Maize Stem Diameter during Drying Cycles: Comparison of Two Methods for Detecting Water Stress , 1994 .

[16]  Brent Clothier,et al.  Water Use of Kiwifruit Vines and Apple Trees by the Heat-Pulse Technique , 1988 .

[17]  Elias Fereres,et al.  Can almond trees directly dictate their irrigation needs , 2003 .

[18]  W. R. N. Edwards,et al.  Transpiration from a kiwifruit vine as estimated by the heat pulse technique and the Penman-Monteith equation , 1984 .

[19]  D. Turner,et al.  Measurements of plant and soil water status and their association with leaf gas exchange in banana (Musa spp.): a laticiferous plant , 1998 .

[20]  R. Zweifel,et al.  Link between diurnal stem radius changes and tree water relations. , 2001, Tree physiology.

[21]  D. S. Intrigliolo,et al.  Programación del riego en cítricos con base en sensores de medida del estado hídrico del suelo y de la planta , 2007 .

[22]  Janine Hasey,et al.  Plant water status as an index of irrigation need in deciduous fruit trees , 1997 .

[23]  J. Girona,et al.  Assessment of peach tree responses to irrigation water ficits by continuous monitoring of trunk diameter changes , 2001 .

[24]  E. Fereres,et al.  Irrigation scheduling of almond trees with trunk diameter sensors , 2004, Irrigation Science.

[25]  A. Torrecillas,et al.  Water relations, growth and yield of Fino lemon trees under regulated deficit irrigation , 1996, Irrigation Science.

[26]  D. Intrigliolo,et al.  Continuous measurement of plant and soil water status for irrigation scheduling in plum , 2004, Irrigation Science.

[27]  L. S. Pereira,et al.  Crop evapotranspiration : guidelines for computing crop water requirements , 1998 .

[28]  J. Alarcón,et al.  Compensation heat-pulse measurements of sap flow for estimating transpiration in young lemon trees , 2005, Biologia Plantarum.

[29]  A. Naor.  Midday stem water potential as a plant water stress indicator for irrigation scheduling in fruit trees. , 2000 .

[30]  F. Moreno,et al.  Transpiration and root water uptake by olive trees , 1996, Plant and Soil.