The impact of solar radiation as well as other factors on plants can be analyzed by changes in the emitted fluorescence of leaves, diffuse reflectance and their color. Diffuse reflectance values allow the determination of parameters that evaluate the activity of the photosynthetic apparatus. These spectra allow determination of leaf color with x and y coordinates brightness, luminance as well as "dominant" wavelength. The emission and reflection spectra, as well as the values of certain ratios, show the characteristics and differences between the analyzed leaves, demonstrating structural and functional changes of the photosynthetic apparatus as a result of adaptation to the environment. All parameters make it possible to distinguish between different varieties of pear and to evaluate the influence of growing conditions on the photosynthetic apparatus.