S12 - Session P3 - Herbaceous sap flux as an estimate of whole plant transpiration for irrigation management

Authors: Kahlin Wacker *, Gaylon Campbell

Transpiration measurements can aid in determination of water consumption and better irrigation control. Using a heated needle sap flow sensor, whole plant transpiration can be accurately estimated based on comparison with lysimeters. These cost-effective sensors can be widely deployed in field and greenhouse systems. Several plants were grown in a greenhouse setting and the sap flux measurements were correlated with lysimeter data. The sap flux measurement has reduced sensitivity at high transpirations in current configuration. The transpiration and sap flux correlation in one species of plant had an R^2 of 0.79. This measurement finds strength when paired with energy balance equations to correlate single plant measurements with whole field estimations.