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An evaluation of noninvasive methods to estimate foliar chlorophyll content
Author(s) -
Richardson Andrew D.,
Duigan Shane P.,
Berlyn Graeme P.
Publication year - 2002
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.0028-646x.2001.00289.x
Subject(s) - absorbance , reflectivity , chlorophyll , chlorophyll a , calibration , botany , chemistry , mathematics , environmental science , biology , optics , statistics , chromatography , physics
Summary• Over the last decade, technological developments have made it possible to quickly and nondestructively assess, in situ , the chlorophyll (Chl) status of plants. We evaluated the performance of these optical methods, which are based on the absorbance or reflectance of certain wavelengths of light by intact leaves. • As our benchmark, we used standard extraction techniques to measure Chl a , Chl b , and total Chl content of paper birch ( Betula papyrifera ) leaves. These values were compared with the nominal Chl index values obtained with two hand‐held Chl absorbance meters and several reflectance indices correlated with foliar Chl. • The noninvasive optical methods all provided reliable estimates of relative leaf Chl. However, across the range of Chl contents studied (0.0004–0.0455 mg cm −2 ), some reflectance indices consistently out‐performed the hand‐held meters. Most importantly, the reflectance indices that performed best
were not those most commonly used in the literature. • We report equations to convert from index values to actual Chl content, but caution that differences in leaf structure may necessitate species‐specific calibration equations.