A comparison of two methods for measuring xylem sap flow : a dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Horticultural Science with Honours in the University of Canterbury, Lincoln College

Abstract

Ever since Stephen Hales published "Vegetable Staticks" in 1727, plant physiologists have applied themselves to elucidation of the movement of water in plants, the most significant result probably being Dixon's cohesion theory. In assessing this theory it is necessary to know sap velocity to estimate the forces exerted and use of the heat pulse technique for such determinations has been made.

Heat pulses for sap velocity measurement have been employed widely in plant physiology for a number of experimental uses and it is of interest therefore to check the method against others that are available. The aim of this dissertation is to compare velocity measurements obtained by using heat pulses with those determined by uses of a radioactive tracer.