Analysis of spectral differences of some selected cotton varieties

摘要

Canopy reflectance spectra of 28 cotton varieties were measured by using an ASD field spectroradiaometer in the field. We used the continuum-removal technique to calculate the 690 nm absorption feature parameters (wavelength, depth, width, area and asymmetry), and we calculated the red-edge wavelength of the cotton varieties. At a 1 nm spectral sampling interval, a maximum of 10 varieties could be separated using the wavelength. The maximum numbers of varieties that are distinguishable using the width of the absorption peak, red-edge location and the greatest derivative reflectance are 8, 4 and 18, respectively. Among the red-edge locations of the 28 cotton varieties, 22 are 718 nm and the differences among the remaining 6 are within 5 nm. This implies that the red-edge location may be used as an identifier for the cotton crop, to differentiate it from other plant species.