Identification of Biochemical Composition and Pesticides Residue in Ten Rose Cultivars Leaves Using FT-IR Spectroscopy

Abstract

In order to optimize the application of nutritive solutions and the phytosanitary treatments with direct influence on the quality of cut roses from hydroponic culture (soilless culture), it is necessary to study the biochemical composition of the different organs of the plant (leaves). By FT-IR spectroscopy using the standard KBr pellet technique; it was possible to differentiate between 10 Rosa cultivars based on the chemical composition of the leaves and also to identify the pesticide residue within the leaf tissues and some of its effects. Thus, it was observed that the intensity of the bands corresponding to amide I (proteins) and aromatic compounds were weaker in leaf sheath and petiole compared with the leaf lamina. Aldehydes were present only in leaf sheath and petiole and not in the leaf lamina. As for the six pesticides tested, simple bond vibration C–H corresponding to aromatic compounds has been detected at 817 cm-1 and 805 cm-1 in the samples treated with penconazole based pesticide (Topas) and a triadimenol with folpet pesticide (Shavit). Also, application of penconazole increases the concentration of polisaccharides in the treated leaves, while a strong intensity band that could be attributed to the presence of halogenated compounds (chlorinated) C-Cl can be observed at 715 cm-1 for the samples treated with the triadimenol and folpet pesticide. The overall results of the present study could provide helpful information for the development of pesticides that have a shorter persistence and a lower biochemical influence on the plant tissues.