Non-Invasive Method to Monitor Plant Water Potential of an Olive Orchard Using Visible and Near Infrared Spectroscopy Analysis

Poblete-Echeverria, C; Ortega?Farias, S.; Lobos GA.; Romero, S.; Ahumada L.; Escobar A.; Fuentes, S

Keywords: spectrometer, climate change, wavelength, olive, pressure chamber

Abstract

Plant water status is an important factor to be quickly and accurately assessed temporally and spatially to maintain yield and quality standards in a changing environment. The pressure chamber is the most common method to measure midday stem water potential (MSWP), which is used as an accurate indicator of plants water status. However, the use of the latter method has the disadvantages of being manual, destructive, slow and impractical to have a good spatial representation of plant water status of a whole olive orchard. The objective of this research was to test an indirect method to estimate MSWP using visible and near infrared (NIR) spectroscopy analysis. This method is non-destructive and quick to implement in the field having the extra advantage of assessing the whole tree with a single measurement using short-range remote sensing. In this study, MSWP was measured using a pressure chamber (PMS Instrument Co. USA) to characterize water status of olive trees in a commercial drip-irrigated 'Arbequina' orchard (Pencahue, Region del Maule, Chile). Canopy reflectance was measured between 350 and 2500 nm wavelength region with a spectrometer FieldSpect3 (Analytical Spectral Device, ASD Co., USA) from 2.5 m distance. The spectroscopy analysis was done using partial least squares (PLS) regression by the Unscramble software. The validation process showed a root mean square error (RMSE) equal to 0.88 MPa and coefficient of determination (R-2) equal to 0.75. These results showed that the non-invasive method, using spectral reflectance data, could obtain a surrogate of stem water potential of olive trees, providing the possibility to screen more samples under field conditions and to automate the data gathering and analysis once a calibration curve is developed.

Más información

Título según WOS: Non-Invasive Method to Monitor Plant Water Potential of an Olive Orchard Using Visible and Near Infrared Spectroscopy Analysis
Título de la Revista: IX INTERNATIONAL SYMPOSIUM ON IRRIGATION OF HORTICULTURAL CROPS
Volumen: 1057
Editorial: INT SOC HORTICULTURAL SCIENCE
Fecha de publicación: 2014
Página de inicio: 363
Página final: 368
Idioma: English
Notas: ISI