Chlorophyll Assessment and Stress Detection from Vegetation Optical Properties

Vegetation monitoring is one of the essential applications of remote sensing. Regarding agricultural lands, a primary goal is crop state assessment throughout the growing season. Remote sensing techniques make use of multispectral data to estimate plant biophysical and biochemical characteristics by implementing quantitative relationships between crop growth variables and spectral properties. Chlorophyll is a key biochemical component that is responsible for photosynthesis and is a physiological indicator of plant condition. Changes in plant pigment content can be used to assess the impact of environmental stresses. In this paper, we present results from ground-based spectrometry studies of the spectral behaviour of agricultural species in relation to varying chlorophyll. Multispectral data were analyzed to reveal the performance of different spectral indicators for chlorophyll estimation. Reflectance factors, vegetation indices, red edge shift, transmittance spectra, chromaticity features and fluorescence parameters were related to chlorophyll content and the statistical significance of plant spectral response to chlorophyll variations was examined. High correlations were observed and empirical relationships derived linking plant optical properties and chlorophyll content. These relationships were used for plant stress diagnosis in terms of chlorophyll synthesis inhibition.