Continuous trunk diameter recording can reveal water stress in peach trees

The water status of a peach tree is traditionally monitored by measuring its predawn or midday leaf water potential or midday stem water potential. A study conducted on ‘O'Henry’ peach trees at the Kearney Agricultural Center showed that continuous monitoring of trunk diameter can also be an accurate technique of detecting water stress. The trees were evaluated during 21 days of underirrigation followed by 17 days of full irrigation. Trunk-based measurements were generally more sensitive than discrete measurements to both the onset of water stress and the magnitude of tree water deficits. Parameters based on trunk diameter monitoring correlated well with established physiological parameters of plant water status. These trunk diameter oscillations, which are only available from continuous monitoring, hold promise for improving the precision of irrigation decision making.