The article presents the results of a study of spectral reflectance characteristics of crops produced in the field of optical remote methods. It was established that during the vegetation period the main factors affecting the reflectance of agrocenosis, are morphological and physiological parameters , architectonic,  height of the Sun h₀ and the viewing angle φ. Found that the minimum brightness of crops accounted for angles 25 ° - 30 ° with respect to nadir . By increasing the angle of view is shown the effect of back shine in the red and infrared. This leads to an increase of spectral brightness coefficients in these areas. Found that the optimal time of measurement of reflection factor agrocenosis is between 11 to 16 hours.