Selection of the wavelengths of peak values in analyzing leaf water status by using leaf reflectance, transmittance and absorptance in corn plants

A field experiment consisting of eleven corn cultivars, three nitrogen level treatments and two population treatments to investigate the relationships among the leaf water content to leaf reflectance, transmittance and absorptance in different spectral regions of water absorption. One hundred leaves from four growth stages were analyzed. It was observed that the central wavelengths of peak values of leaf reflectance, transmittance and absorptance were at 974 nm, 1160 nm and 1440 nm in the water absorption regions. The leaf reflectance and absorptance at 974 nm, 1160 nm and 1440 nm were better related to the leaf water content than the leaf transmittance.The relationships among the leaf reflectance, transmittance and absorptance tended to be stronger at 1440 nm than that at 974 nm or at 1160 nm, and the leaf reflectance, transmittance and absorptance appeared to be slightly better related to the leaf water content than that at 974 nm or at 1160 nm. The results indicated that 1440 nm was the best wavelength of peak values in analyzing plant water status by using reflectance and absorptance.