Detection of fruit tree water status in orchards from thermal remote sensing images

Abstract

Remotely sensed crop water stress index (CWSI) can be used to depict fruit tree water status. The aim of this study was: i) to develop an empirical approach for assessing the CWSI of peach trees throughout a growing season and validate it with ground-based leaf water potential (Ψ leaf) measurements, and ii) to detect the spatial variability of fruit tree water status in a 2-ha peach orchard and throughout a complete growing season based on remotely estimates of leaf water potential (Ψrem) from airborne thermal imagery. Ψ rem was estimated from the seasonal relationships with CWSI. This study was carried out during 2012 and 2013 growing seasons. CWSI and Ψ leaf were significantly correlated both years indicating a similar tendency between years, but differences between phenological stages. Differences in the spatial variability of peach tree water status were successfully remotely detected, demonstrating that remote estimates of leaf water potential can be used for precise irrigation purposes.