Assessing plant vitality with optical techniques
The way radiation interacts with matter provides relevant information about its composition and structure. In the case of radiation interaction with living beings, it can also provide information about their physiological functionality. Humans have always obtained information about the composition and physiological functioning of plants by simple visual assessment, but the developments in physics in the field of spectroscopy and imaging have provided a set of optical techniques that have increased our capacity for analysis, either by making it quantitative or by extending it to wavelength range to which our eyes are not sensitive. This paper presents the non-invasive optical techniques used in plant biology, shows examples of their application to obtain structural and functional information in various contexts, including the assessment of biostimulants, and discusses the future of these techniques in the framework of high-throughput plant phenotyping and the new generation of Earth observation satellites.
Acknowledgements: This research was funded by FCT research unit BioISI (UIDP/04046/2020) and the R&D project INTERPHENO (PTDC/ASP-PLA/28726/2017).