Feasibility study on the use of near infrared spectroscopy to measure water status of almond trees

Climate change predictions of increasing CO2 concentration, temperature and a decline in water availability for irrigation have prompted research to develop rapid and accurate plant-based monitoring tools to help assess plant performance under environmental stresses. In this study, an adaptation of Near Infrared (NIR) spectroscopy was investigated as a rapid and non-destructive method to estimate water status of almond trees. Leaves from 12 almond cross-lines were scanned using an ASD FieldSpec® 3 (350-1850 nm) spectrophotometer (Analytical Spectral Devices, Boulder, Co, USA) and then destructively measured using a pressure chamber to obtain stem water potential (Ψstem). All calibrations were developed using partial least squares (PLS) regression with full cross validation. Calibrations for Ψstem assessment showed good prediction ability (SECV <0.4 MPa) for the 12 almond crosses studied thus demonstrating that, with further research, NIR spectroscopy could become a tool to estimate water status of almond trees. © 2018 ISHS.