Fluorescence spectroscopy to detect water stress in orange trees

The laser-induced fluorescence spectroscopy was used to investigate to investigate water stress in orange trees (Citrus aurantium L_N). In our experiments, six three were under water stress conditions and four in regular conditions, as control. The fluorescence spectroscopy was investigated by using a 442-nm 15 mW He-Cd gas multimode discharge laser and 532-nm 10 mW Nd³⁺:YAG laser for fourteen days. The stress manifestation can be detected by variation of fluorescence ratios of the leaves. The fluorescence ratios present a significant variation. The results show that it is possible to observe water stress by analyzing fluorescence spectra of orange leaves. The possibility to develop a tool to detect the water stress in the field is also discussed