Abstract
The drought risk evaluation of cultivating plants is the most important factor on deficit irrigation (DI). The DI, however, often causes the cavitation and embolism followed by growth inhibition of the plant. Acoustic emissions (AE) detected on a stem are associated with cavitation. Authors proposed the model in which the change in AE behavior against the change in drought stress reflects the embolism risk. Furthermore, a stress wave velocity (SWV) through stem was measured to guarantee the decrease in the drought stress of a soil-cultivated plant. In this study, the hybrid measurement of AE and SWV at stem of miniature tomato was done for controlling DI. The change ratio of SWV caused by irrigation, RIV depended on the drought stress. The plants suffered severe drought stress showed that the change ratio of AE occurrence rate caused by irrigation, RIAE was increased. The DI using RIV and RIAE was successful to maintain the yield of fruits with high sugar content.
