Interpretation and physiological significance of blue-green and red vegetation fluorescence

Remote sensing of plant physiological state can be performed by the measurements of UV-excited blue-green leaf fluorescence and/or red chlorophyll fluorescence. The spectral distribution of the red chlorophyll fluorescence, as measured by the F685/F730 fluorescence ratio, can give information on the photosynthetic activity of the plant. By this measurement it is, therefore, possible to obtain in remote sensing data similar to those of the fluorescence induction kinetics practicable only as punctual detection. Blue-green leaf fluorescence provides a complementary mean of investigation of vegetation stresses since it comes mostly from many different UV-absorbing pigments present in the leaf epidermis