Abstract: To determine the correlativity between canopy reflectance parameters and leaf chlorophyll content of flue-cured tobacco, this paper measured the canopy reflectance spectrum and the contents of leaf chlorophyll a (Chl-a), chlorophyll b (Chl-b), and carotenoid (Cars) under different N application rate, and analyzed the correlations between the spectrum parameters and the chlorophyll contents. With the increase of N application rate, the contents of fresh leaf Chl-a, Chl-b, and Cars at spherical plant stage and fast growing stage all increased, and the reflection in near infrared bands enhanced but that in visible bands decreased. At topping stage, the contents of Chl-a, Chl-b, and Cars and the canopy reflectance did not present notable changing trend. Within the visible bands, the reflection of 460 nm was significantly positively correlated with the contents of Chl-a, Chl-b, and Cars, while the reflection of other bands was significantly negatively correlated with the contents of the three pigments. Within the near infrared bands, the reflection of 1480 nm was significantly negatively correlated with the contents of Chl-a, Chl-b, and Cars, while the reflection of other bands was significantly positively correlated with the contents of the three pigments. The best regression equations to determine the quantitative relations between the contents of fresh leaf Chl-a, Chl-b, and Cars and the spectrum parameter (ratio vegetation index, RVI) were power function, power function, and exponential function respectively, i.e., Chl-a=0.250RVI(730,550)^1.511, Chl-b=0.049RVI(730,550)^1.841, and Cars=0.0998e^{0.379 RVI(730,550)}.

Key words: Vicia faba, Micro-nucleus ratio, Cd²⁺, Surfactant, Acid rain