Relationship between Sap Flow, Maximum Daily Shrinkage and Other Ecophysiological Parameters in Prunus avium Subjected to Water Stress

Abstract

Daily sap flow and maximum daily shrinkage (MDS) are two parameters that can be used for irrigation decision-making. In this subchapter we try to understand the different behavior of the two parameters at different timescales. The data come from the anterior assay (Chapter 1A) An assay was raised under controlled conditions where drought was imposed by irrigation withdrawal in cherry plants to compare their response of MDS with that of other ecophysiological parameters commonly used in water relations studies. Results showed contrasting relationships between MDS and daily sap flow depending on the degree of water stress that could be due to stomatal regulation. At a daily timescale, trunk diameter variation and sap flow were related to each other via a loop that differs according to tree water status. MDS resulted more sensitive to drought than sap flow, but the simultaneous use of both indicators rendered complementary information sensitive to the water status of the plants.