Calibrating the compensation heat-pulse technique for measuring sap flow in olive

Abstract

The compensation heat-pulse method, a technique for measuring sap flow in plants, was calibrated for the olive tree. Two calibration experiments were carried out, the excision and the perfusion experiments. A device was designed in our laboratory for the perfusion experiment, which allowed us to calibrate the technique for a range of 0.5 L h-1 to 14 L h-1. The correction factors given by Green and Clothier (1988) for a 2.0 mm wound diameter were found to be valid for the olive tree, except when the tree suffered from significant water stress.