Fecha de publicación: 12/03/2008 Fuente: Wipo "precision agriculture" A plant matter sensor (100), the sensor (100) comprising a pair of parallel spaced apart sensor arms (2) and a control console (3), a first of said arms (2) having a plurality of emitter means (6) spaced along its length, each emitter means (6) configured and arranged to, in use, emit a signal substantially perpendicularly to the said arm to be received by a corresponding receiver means (7) on the second arm (8), the console (3) containing control means to, in use, control the rate, strength and regularity of the signal emitted by each of the said emitter means (6), collection means to, in use, collect data from each receiver means (7) as to the existence or absence of receipt of a signal, processor means to process data received from the control means and the collection means and determine the height of any plant matter traversed by the plant matter sensor (100) and predetermined intervals, and storage means to store the plant matter height data generated by the processor means for subsequent download or analysis.