A weed control system (2) for an agricultural sprayer (1) comprising a camera (3) and a spraying unit (4) with several supply modules, a nozzle (9) and a controller module to receive a weed species detection signal and to control the spraying of chemical agent. The weed control system (2) also comprises a weed species identification unit (5) with a communication module, a memory module and a processing module having several parallel processing cores. Each parallel processing core performs a convolution operation between a sub-matrix constructed from nearby pixels of the image and a predefined kernel stored in the memory module to obtain a feature representation sub-matrix of the pixel values of the image. The processing module computes a probability of presence of a weed species from the feature representation matrix and generates a weed species detection signal.
