Evaluating different metrics from the thermal-based two-source energy balance model for monitoring grapevine water stress

Abstract Precision irrigation management requires operational monitoring of crop water status. However, there is still some controversy on how to account for stress. To address this question, several physiological, physiological metrics have been proposed, such as the leaf/stem potentials, stomatal conductance, or sap flow. On other hand, thermal remote sensing has shown be a promising tool efficiently evaluating stress at adequate spatial and temporal scales, via Crop Water Stress Index (CWSI), one most common indices used assessing plant CWSI relates actual evapotranspiration ET (related canopy radiometric temperature) potential (or minimum temperature). remotely sensed surface temperature from satellite sensors includes mixture soil/substrate temperatures, while what required accurate detection more related metrics, transpiration, latter avoids influence in determining status The Two-Source Energy Balance (TSEB) model widely robust sensing. It capability partitioning into transpiration soil evaporation components, which estimates. This study aims different TSEB its retrievals ET, track vineyard California, part GRAPEX experiment. Four eddy covariance towers were deployed Variable Rate Irrigation system Merlot that was subject periods. In addition, root-zone moisture, conductance collected proxy situ Results showed variable tracking derived leaf with strongest correlation both measured moisture gas exchange measurements. these better ability when observations are taken early after noon.