Estimation of Leaf Water Content of Plants by Spectral Reflectance of Near Infrared Range

Abstract

A non-destructive measuring method for estimating leaf water content was applied for soybean and sweet potato using a spectrophotometer.
In this paper, we tried to find the most effective band and experimental equations suitable for estimating leaf water content of soybean and sweet potato.
1) The most effective wavelength for estimating leaf water content of soybean rFukuyutakaj is 1496 nm. The regression equation is W_SB=-0.352/R_1496nm+22.9, where WSB is leaf water content (H₂Omg/cm²) and R1496nm is spectral reflectance (%) at 1496 nm. In this case, the multiple correlation, coefficient and the SEE (Standard error of estimate) are 0.937 and 0.574 respectively.
2) The most effective wavelength for estimating leaf water content of sweet potato [Benikomachi] is 1384 nm. The regression equation is W_SP=-0.609×R_1384nm+47.2, where W_SP is leaf water content (mg/cm²) and R_1384nm is spectral reflectance (%) at 1384 nm. In this case, the multiple correlation coefficient and the SEE are 0.944 and 1.875 respectively.