'George Washington University Institute for Ethnographic Research (Project Muse)'
Abstract
The identification of a reliable and practical water stress indicator and the
corresponding threshold value, for irrigation scheduling, is a classical concern in water
management in agriculture. This is not well solved for woody crops, especially those
not traditionally irrigated, usually with large roots systems. Aiming to contribute to
these studies, we measured water fluxes and some water stress indicators in an olive
grove in south Portugal, during successive stress cycles. We report the first preliminary
results during a stress cycle in August-September 2011, using sap flow, leaf water
potential at predawn, stem diameter variations and soil water content, from which
some indicators were derived. From the preliminary information obtained we could
not identify a threshold value but very good relationships were found, between the
selected automated and not automated variables, useful for farmers and engineering
applications. These first encouraging results need confirmation and further analysi