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Auswirkungen einer Blattinfektion durch Mycosphaerella auf die spektralen Reflexionseigenschaften des jungen Laubes von Eucalyptus globulus
Author(s) -
Pietrzykowski E.,
Stone C.,
Pinkard E.,
Mohammed C.
Publication year - 2006
Publication title -
forest pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.535
H-Index - 49
eISSN - 1439-0329
pISSN - 1437-4781
DOI - 10.1111/j.1439-0329.2006.00459.x
Subject(s) - eucalyptus globulus , mycosphaerella , biology , reflectivity , eucalyptus , horticulture , botany , optics , physics
Summary Mycosphaerella leaf disease (MLD) can cause significant discoloration, necrosis and defoliation in commercial plantations of young Eucalyptus globulus . This study investigated the spectral reflectance changes that result in E. globulus foliage from Mycosphaerella infection. Spectral reflectance measurements were made on healthy and infected E. globulus foliage in the visible and near‐infrared wavelengths (400–1000 nm). Reflectance ( R ) at 760 nm produced the largest difference between the extremes of disease severity classes. The wavelength most sensitive to infection severity was R 678 nm. Other sensitive wavelengths were located between 480 and 500 nm. The wavelengths near 708 and 550 nm appeared relatively insensitive to infection severity. The reflectance index best correlated to leaf infection was R 678/ R 550 ( r = 0.841, p < 0.0001). This index was used in a linear regression model for successfully predicting leaf infection levels from an independent data set ( r = 0.95, p < 0.0001).