Next Article in Journal
Previous Article in Journal
A correction was published on 24 February 2014, see Remote Sens. 2014, 6(2), 1760-1761.

Remote Sens. 2013, 5(12), 6647-6666; doi:10.3390/rs5126647
Article

Stem Water Potential Monitoring in Pear Orchards through WorldView-2 Multispectral Imagery

1,* , 1
, 2
 and 1
Received: 27 September 2013; in revised form: 15 November 2013 / Accepted: 26 November 2013 / Published: 4 December 2013
View Full-Text   |   Download PDF [462 KB, uploaded 19 June 2014]   |   Browse Figures
Abstract: Remote sensing can provide good alternatives for traditional in situ water status measurements in orchard crops, such as stem water potential (Ψstem). However, the heterogeneity of these cropping systems causes significant differences with regards to remote sensing products within one orchard and between orchards. In this study, robust spectral indicators of Ψstem were sought after, independent of sensor viewing geometry, orchard architecture and management. To this end, Ψstem was monitored throughout three consecutive growing seasons in (deficit) irrigated and rainfed pear orchards and related to spectral observations of leaves, canopies and WorldView-2 imagery. On a leaf and canopy level, high correlations were observed between the shortwave infrared reflectance and in situ measured Ψstem. Additionally, for canopy measurements, visible and near-infrared wavelengths (R530/R600, R530/R700 and R720/R800) showed significant correlations. Therefore, the Red-edge Normalized Difference Vegetation Index (ReNDVI) was applied on fully sunlit satellite imagery and found strongly related with Ψstem (R2 = 0.47; RMSE = 0.36 MPa), undoubtedly showing the potential of WorldView-2 to monitor water stress in pear orchards. The relationship between ReNDVI and Ψstem was independent of management, irrigation setup, phenology and environmental conditions. In addition, results showed that this relation was also independent of off-nadir viewing angle and almost independent of viewing geometry, as the correlation decreased after the inclusion of fully shaded scenes. With further research focusing on issues related to viewing geometry and shadows, high spatial water status monitoring with space borne remote sensing is achievable.
Keywords: stem water potential; multispectral imagery; robust estimation; vegetation indices; pear orchards stem water potential; multispectral imagery; robust estimation; vegetation indices; pear orchards
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
  • Correction

    Correction (PDF, 148 KB)

    A correction was published on 25 Feburary 2014 http://www.mdpi.com/2072-4292/5/12/6647

Export to BibTeX |
EndNote


MDPI and ACS Style

Van Beek, J.; Tits, L.; Somers, B.; Coppin, P. Stem Water Potential Monitoring in Pear Orchards through WorldView-2 Multispectral Imagery. Remote Sens. 2013, 5, 6647-6666.

AMA Style

Van Beek J, Tits L, Somers B, Coppin P. Stem Water Potential Monitoring in Pear Orchards through WorldView-2 Multispectral Imagery. Remote Sensing. 2013; 5(12):6647-6666.

Chicago/Turabian Style

Van Beek, Jonathan; Tits, Laurent; Somers, Ben; Coppin, Pol. 2013. "Stem Water Potential Monitoring in Pear Orchards through WorldView-2 Multispectral Imagery." Remote Sens. 5, no. 12: 6647-6666.


Remote Sens. EISSN 2072-4292 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert