Fecha de publicación: 13/02/2003 Fuente: Wipo "precision farming" The invention concerns a radiometric device for determining in situ the biochemical content of leaves (F), comprising means (7) for emitting light on the surface of a leaf, means (3) for sensing the light beam transmitted through the leaf thickness and for delivering electric signals representing absorption characteristics of said leaf at least at a predetermined wavelength. The emitted light is in the form of a single beam emitted by a light source with broad wavelength band and the sensing means comprise a plurality of stacked photodiodes successively traversed by the transmitted beam. The invention is useful in particular in precision farming and for scientific research in the field of environment and ecosystems.