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Reflectance and Internal Structure of Leaves from Several Crops During a Growing Season 1
Author(s) -
Sinclair T. R.,
Hoffer R. M.,
Schreiber M. M.
Publication year - 1971
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1971.00021962006300060012x
Subject(s) - reflectivity , wavelength , chlorophyll , agronomy , growing season , absorption (acoustics) , spectral line , crop , infrared , chemistry , botany , horticulture , biology , materials science , optics , optoelectronics , physics , astronomy , composite material
The reflectance spectra from 500 to 2600 nm were measured for the leaves of six agronomic crops. Leaf samples were collected at three periods during the growing season; water content was determined and cross sections of the internal leaf structure were observed microscopically. The reflectance spectra of all fresh, green leaves were very similar. However, reflectance at all wavelengths increased as the crop matured and their leaves senesced. Decreased absorption by chlorophyll apparently increased the reflectance of the visible wavelengths (500 to 700 nm). Similarly, water loss accompanying senescence resulted in an increased reflectance in the far infrared wavelengths (1300 to 2600 nm). Changes in the internal structure of leaves caused increases in the near infrared wavelengths (700 to 1300 nm).