Abstract:

A field experiment consisting of different nitrogen levels and three rice cultivars was conducted to investigate the relationships among the leaf chlorophyll concentration and leaf absorptance, transmissivity and reflectance. It was observed that the central wavelengths of peak values of the leaf reflectance (R), transmission (T) and absorptance (A) were 440nm, 480nm, 630nm and 681nm. At 630nm the relationships among the leaf absorptance, transmissivity, reflectance and leaf chlorophyll concentration were all extremely significant, and the relationships between absorptance and transmission were stronger than that between the leaf reflectance and transmission or absorptance. Step regression analysis was used to establish chlororphyll concentration prediction models and the relationship between chlororphyll concentration measured values. The estimated values indicated that compared with predicted chlororphyll concentration using single wavelength band 630nm, R square increases significantly using liner regression models established with A440, A480, A681 predicting chlororphyll a concentration, with T440, T480, T630 predicting chlororphyll a concentration and with T630, T480, T681 predicting chlororphyll b concentration.