TY - JOUR
T1 - The potential of the spectral ‘water balance index’ (WABI) for crop irrigation scheduling
AU - Rapaport, Tal
AU - Hochberg, Uri
AU - Cochavi, Amnon
AU - Karnieli, Arnon
AU - Rachmilevitch, Shimon
N1 - Publisher Copyright:
© 2017 The Authors.
PY - 2017/11/1
Y1 - 2017/11/1
N2 - Hyperspectral sensing can detect slight changes in plant physiology, and may offer a faster and nondestructive alternative for water status monitoring. This premise was tested in the current study using a narrow-band ‘water balance index’ (WABI), which is based on independent changes in leaf water content (1500 nm) and the efficiency of the nonphotochemical quenching (NPQ) photo-protective mechanism (531 nm). • The hydraulic, photo-protective and spectral behaviors of five important crops – grapevine, corn, tomato, pea and sunflower – were evaluated under water deficit conditions in order to associate the differences in stress physiology with WABI suitability. • Rapid alterations in both leaf water content and NPQ were observed in grapevine, pea and sunflower, and were effectively captured by WABI. Apart from water status monitoring, the index was also successful in scheduling the irrigation of a vineyard, despite phenological and environmental variability. Conversely, corn and tomato displayed a relatively strict stomatal regime and/or mild NPQ responses and were, thus, unsuitable for WABI-based monitoring. • WABI shows great potential for irrigation scheduling of various crops, and has a clear advantage over spectral models that focus on either of the abovementioned physiological mechanisms.
AB - Hyperspectral sensing can detect slight changes in plant physiology, and may offer a faster and nondestructive alternative for water status monitoring. This premise was tested in the current study using a narrow-band ‘water balance index’ (WABI), which is based on independent changes in leaf water content (1500 nm) and the efficiency of the nonphotochemical quenching (NPQ) photo-protective mechanism (531 nm). • The hydraulic, photo-protective and spectral behaviors of five important crops – grapevine, corn, tomato, pea and sunflower – were evaluated under water deficit conditions in order to associate the differences in stress physiology with WABI suitability. • Rapid alterations in both leaf water content and NPQ were observed in grapevine, pea and sunflower, and were effectively captured by WABI. Apart from water status monitoring, the index was also successful in scheduling the irrigation of a vineyard, despite phenological and environmental variability. Conversely, corn and tomato displayed a relatively strict stomatal regime and/or mild NPQ responses and were, thus, unsuitable for WABI-based monitoring. • WABI shows great potential for irrigation scheduling of various crops, and has a clear advantage over spectral models that focus on either of the abovementioned physiological mechanisms.
KW - crop physiology
KW - hyperspectral spectroscopy
KW - irrigation
KW - precision agriculture
KW - water balance index (WABI)
UR - http://www.scopus.com/inward/record.url?scp=85047788067&partnerID=8YFLogxK
U2 - 10.1111/NPH.14718
DO - 10.1111/NPH.14718
M3 - Article
C2 - 28795772
AN - SCOPUS:85047788067
SN - 0028-646X
VL - 216
SP - 741
EP - 757
JO - New Phytologist
JF - New Phytologist
IS - 3
ER -