have applied laser-induced fluorescence spectroscopy to investigate biological processes in orange trees. They have investigated water stress and Citrus Canker, which is a disease produced by the Xanthomonas axonopodis pv. citri bacteria. They have discriminated the Citrus Canker‘s contaminated leaves from the healthy leaves using a more complex analysis of the fluorescence spectra. However, they were unable to discriminate it from another disease.