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棉 花 学 报 Cotton Science 2008，20(3)：217-222
Hyperspectral Estimating Modelings of Cotton LAI and the Above-ground Dry Matter Accumulation Abstract：Hyperspectral data of cotton canopy were measured with ASD FieldSpec during different growth stages, and simultaneously, leaf area index(LAI), above-ground dry biomass accumulation(ADMA) were acquired. The correlations between the reflective spectra data and cotton canopy LAI, ADMA were analyzed, respectively. The result indicated that the maximum correlation coefficients between reflective spectra data and LAI, ADMA of cotton were occurred at wavelength 783 nm(r=0.6394**) and 766 nm(r=0.6287**), respectively. Reflective spectra data were statistically analyzed to establish five function modelings of LAI, ADMA of cotton, based on ratio vegetation index(RVI), and normalized difference vegetation index(NDVI). The RVI modeling has a higher precision. According to correlation analysis between the first derivative spectra data and LAI, ADMA of cotton, the sensitivity wavelength has take placed at 736 nm(r=0.6769**) and 742 nm(r=0.6847**),respectively. Using derivative spectra value of wavelength 736 nm and 742 nm to establish the linear regression modelings of LAI and ADMA, all reached 1% significant level. It showed that value of sensitivity wavelength of the first derivative spectra has certain estimating capacity for LAI and ADMA of cotton.
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