Ben-Gal, A., Soil, Water and Environmental Sciences, Agricultural Research Organization, Gilat Research Center, Mobile post Negev 2, 85280, Israel
Kool, D., Irrigation and Water Engineering, Wageningen University, Netherlands
Agam, N., Soil, Water and Environmental Sciences, Agricultural Research Organization, Gilat Research Center, Mobile post Negev 2, 85280, Israel
van Halsema, G.E., Irrigation and Water Engineering, Wageningen University, Netherlands
Yermiyahu, U., Soil, Water and Environmental Sciences, Agricultural Research Organization, Gilat Research Center, Mobile post Negev 2, 85280, Israel
Yafe, A., Soil, Water and Environmental Sciences, Agricultural Research Organization, Gilat Research Center, Mobile post Negev 2, 85280, Israel
Presnov, E., Soil, Water and Environmental Sciences, Agricultural Research Organization, Gilat Research Center, Mobile post Negev 2, 85280, Israel
Erel, R., Soil, Water and Environmental Sciences, Agricultural Research Organization, Gilat Research Center, Mobile post Negev 2, 85280, Israel
Majdop, A., Soil, Water and Environmental Sciences, Agricultural Research Organization, Gilat Research Center, Mobile post Negev 2, 85280, Israel
Zipori, I., Fruit Tree Sciences, Agricultural Research Organization, Gilat Research Center, Israel
Segal, E., Soil, Water and Environmental Sciences, Agricultural Research Organization, Gilat Research Center, Mobile post Negev 2, 85280, Israel
Rüger, S., Lehrstuhl für Biotechnologie, Biozentrum, Universität Würzburg, Germany
Zimmermann, U., Lehrstuhl für Biotechnologie, Biozentrum, Universität Würzburg, Germany
Cohen, Y., Agricultural Engineering, Agricultural Research Organization, Volcani Center, Israel
Alchanatis, V., Agricultural Engineering, Agricultural Research Organization, Volcani Center, Israel
Dag, A., Fruit Tree Sciences, Agricultural Research Organization, Gilat Research Center, Israel

Drainage-weighing lysimeters allowed monitoring of water balance components of non-bearing olive (Olea europaea cv Barnea) trees over a 3-month period including short-term events of controlled but severe water stress. The objective of the study was to evaluate a variety of soil and plant-based water status and drought stress monitoring methods on the basis of tree-scale evapotranspiration (ET). As the trees entered into and recovered from water stress, meteorological data, actual ET (ETa), soil water content and changes in leaf turgor pressure were continuously monitored. Additionally, midday measurements of stem water potential, stomatal conductance, canopy temperature, and quantum yield of PSII photochemistry were conducted. Diurnal (dawn to dusk) measurements of all the above were made hourly on days of maximum stress. Shoot elongation rate was measured for periods of stress and recovery. Quantum yield of PSII photochemistry, stomatal conductance, and stem water potential all successfully indicated reductions in whole-tree water consumption beginning at moderate stress levels. These measured parameters fully recovered to the levels of non-stressed trees soon after water application was renewed. Shoot elongation was reduced 25-30% for the 10-day period during and following drought and recovered thereafter to levels of non-stressed trees. Whole-tree ETa was reduced by as much as 20% even following full recovery of the leaf level parameters, suggesting reduced canopy size and growth due to the stress period. Non-destructive, continuous (turgor pressure) and remotely sensed (canopy temperature) methods showed promising potential for monitoring effects of water stress, in spite of technological and data interpretation challenges requiring further attention. © 2010 Elsevier B.V.