Percent loss of conductivity of sweet cherry (Prunus avium `Emperor Frances') under dry conditions was determined by measuring hydraulic conductivity before and after high pressure perfusion removal of xylem embolisms. Cut stems were allowed to dry for 0 to 8 hours, recut underwater and the rate of flow of solution through the stems measured under positive pressure (∼8.0 kPa). Hydraulic conductivity (Kh)was then calculated, and typical values for well hydrated stems were 6 × 10-9 m4MPa-1s-1. Embolisms were then dissolved by high pressure perfusion (125kPa) and the subsequent flow rate measured. A second Kh was then calculated and the difference in Kh values before and after the high pressure treatment used as a measure of % loss of conductivity (or % xylem embolism). A curve of the `vulnerability' to xylem embolism was generated by plotting % loss of conductivity against initial stem water potential. The curve shows the stems undergo xylem embolism as soon as stem water potential reaches -1.5MPa, and at stem water potentials of -3 MPa, the stems are over 80% embolized. This cultivar appears to be vulnerable to embolism relative to other studied woody species, and xylem dysfunction likely is a problem early in a drying period. However, a particular rootstocks ability to supply water during a dry period and a cultivar's ability to limit water loss by stomatal closure will dictate the exact water potentials in the stem and thus its level of embolism.