Abstract

Detection of xylem cavitation audio acoustic emissions (AAE) and ultrasonic audio emissions (UAE) from plant tissues during periods of water stress are well known in the literature of plant physiology (Ritman and Milburn 1988, Ritman and Milburn 1991). Detection of the frequencies of emission generally depend upon attenuation by tissues and on the resonant properties of conduits (Fig. 1). It is generally accepted that tracheids are responsible for AAE but vessels are not essential for audio. Previous measurements reported in literature were limited by the dynamic range of the measuring microphone (Sandford and Grace, 1985).

© 1994 IEEE