Detection And Analysis Of Ultrasonic Emission Signals From Plants

Ultrasonic emission is a phenomenon with cavitation of vessels or tracheids. Cavitation and embolism status could be studied well by detecting and analyzing of ultrasonic emission. It is important for study plant physiology of water, fight a drought and water-saving irrigation.The main contents of this paper is to compare some sensors, then build up a LabVIEW-based detection and analysis of ultrasonic emission system. This instrument has the function of detection the ultrasonic emission signal, waveform memory, waveform playback, parameter extraction, spectrum analysis and wavelet analysis. Its sensitivity and the quantity of collected signal is as good as foreign products. In addition, three sets of instruments were used to detect ultrasonic emission signals of the slice of Platycladus orientalis (Linn.)Franco, Koelreuteria paniculata Laxm, Platanus occidentalis Linn and Acer truncatum Bunge, and the first time ultrasonic emission signals of trees were analyzed detailedly. Detailed information was provided for the future research ultrasonic emission of trees.The results show that the ultrasonic emission signals of Platycladus orientalis (Linn.)Franco, Koelreuteria paniculata Laxm, Platanus occidentalis Linn and Acer truncatum Bunge are common, and also different. All the parameters distribution of ultrasonic emission signals of these four species in 50 slices have similar trend. Specifically, the amount of signals from Koelreuteria paniculata Laxm slices was the largest and average energy of every signal was max. The amount of signals and average energy of every signal from Platycladus orientalis (Linn.)Franco slices was the least.The amount of signals and average energy of every signal from Platycladus orientalis (Linn.)Franco and Platanus occidentalis Linn slices was biggest at the medium temperature (22±1.5℃), and was less at the higher temperature (29±1℃) and lower temperature (18±1℃). In different seasons ultrasonic emission signals from Platycladus orientalis (Linn.)Franco and Platanus occidentalis Linn slices was quite different. The amount of signals and characteristic parameters of ultrasonic emission were larger in winter than in summer. The amount of signals and duration were smaller than in summer, and amplitude, rise-time, ringing counts were not very different.