# Making Sense of Light: The Use of Optical Spectroscopy Techniques in Plant Sciences and Agriculture
###### Abstract  
As a result of the development of non-invasive optical spectroscopy, the number of prospective technologies of plant monitoring is growing. Being implemented in devices with different functions and hardware, these technologies are increasingly using the most advanced data processing algorithms, including machine learning and more available computing power each time. Optical spectroscopy is widely used to evaluate plant tissues, diagnose crops, and study the response of plants to biotic and abiotic stress. Spectral methods can also assist in remote and non-invasive assessment of the physiology of photosynthetic biofilms and the impact of plant species on biodiversity and ecosystem stability. The emergence of high-throughput technologies for plant phenotyping and the accompanying need for methods for rapid and non-contact assessment of plant productivity has generated renewed interest in the application of optical spectroscopy in fundamental plant sciences and agriculture. In this perspective paper, starting with a brief overview of the scientific and technological backgrounds of optical spectroscopy and current mainstream techniques and applications, we foresee the future development of this family of optical spectroscopic methodologies.  
fluorescence spectroscopy; high-throughput plant phenotyping; infrared spectroscopy; imaging spectroscopy; near-infrared spectroscopy; precision agriculture; Raman spectroscopy; point spectral measurements; visible spectroscopy +
Footnote †: journal:  
1 CEOT Campus de Gambelas, Universidade do Algarve, FCT, Ed.2, 8005-189 Faro, Portugal; [EMAIL_ADDRESS]  
1 CEOT Campus de Gambelas, Universidade do Algarve, FCT, Ed.2, 8005-189 Faro, Portugal; rguerra@ualg.  
abiotic stress; to screen various disorders and pathologies; to determine the impact of plant species onto the ecosystems' biodiversity and stability; and to assess, remotely the physiological status of photosynthetic biofilms. These many applications have been compiled in various recent reviews on the research topic [1; 2; 3; 4; 5]. The emergence of high-throughput plant phenotyping technologies and the concomitant need for rapid and contactless technologies for the assessment of plant performance renewed the interest in the application of optical spectroscopy techniques in plant sciences [6; 7; 8; 9]. Furthermore, the new generations of earth observation satellites brought increased attention to techniques such as the spectral analysis of solar-induced fluorescence (SIF). Finally, various optical spectroscopic techniques have become valuable smart tools in precision agriculture as well as in the assessment of horticultural product quality across the supply chains. This has contributed to a more sustainable, safe, traceable, and high-quality fresh commodities production [10; 11; 12]. In this perspective paper, departing from a brief review of the scientific and technological history of optical spectroscopy, and an overview of the current main methodologies and applications in the fundamental plant sciences and in agriculture, we foresee future developments of this family of optical spectroscopy techniques.