New technology for determining vine water status and controlling vineyard

We confirmed that ultrasonic acoustic emissions occur in field-grown grapevines subjected to water deficits. The appropriate sensor and frequency for adequate detection was determined. Although we can record acoustic emission rates in the field, we are not satisfied with the present sensor attachment. For Cabernet Sauvignon vines in the Lodi area, differences in the rate of acoustic emissions at the onset of veraison were easily resolved between vines receiving irrigation every other day and vines from which water was withheld up to that point. The rate of acoustic emissions from the stressed vines was two to five times greater than from the irrigated vines at midday. When water was withheld (at 50%veraison) from some vines for only six days, there were again large differences (up to five-fold) in the rate of acoustic emissions at midday. The results suggest that the water status of a vineyard may be estimated daily and automatically without grower labor input.