Abstract: In this paper, we present a novel photonic sensor engine that enables farmers to differentiate green plants one from another (“green from green”) based on spectral plant “fingerprinting”. This advanced photonic sensor engine operates in the visible to infra\|red wavelength range and enables the capture and analysis of spectral data for accurate discrimination and detection of weeds and crop in laboratory conditions as well as in the field.The sensor is developed through close interdisciplinary research collaboration between the Western Australian Centre of Excellence for MicroPhotonic Systems, Photonics Detection System, Pty Ltd, Australia, and China Daheng Group, China. The outcome of this collaboration is the development of world\|first weed sensors that enable site\|specific application of herbicides, leading to a significant improvement in crop yield, substantial herbicide savings of up to 80%, environmental benefits, less water usage, and significant improvements to profitability in the agricultural and other sectors.