Etude de la réflectance spectrale de feuilles d’olivier (Olea europaea L.) atteintes de cercosporiose (Pseudocercospora cladosporioides Sacc.).

Abstract

The olive tree is one of the oldest cultivated trees in Mediterranean countries. Our work consists of cataloging. Cercospora leaf spot of the olive tree (or olive plumbing) is a serious fungal disease that affects olive groves. The objective of this study is to detect the presence of the fungus Pseudocercospora cladosporioides in olive leaves using the JETI Spectraval 1501 device and the DUALEX Scientific sensor (FORCE A). In order to achieve this objective, we collected leaves from the olive tree inoculated with Pseudocercospora cladosporioides and healthy leaves. The JETI Spectraval 1501 device was used to perform hyperspectral measurements, which allow for measuring the reflectance of light radiation over a wavelength range of 380 nm to 780 nm. This study aims to detect the presence of the fungus Pseudocercospora cladosporioides in olive leaves using the JETI Spectraval 1501 device and the DUALEX Scientific sensor (FORCE A). It is crucial to detect fungal infections early in order to ensure effective disease management. Furthermore, the Dualex optical sensor provides an easy, quick, and non-destructive measurement of chlorophyll, flavanols, and anthocyanins present in the leaves. Based on the variability of reflectance peaks, their averages, and standard deviations, the analyses conducted can indicate the presence of fungi in relation to the spectral examinations of healthy leaves and the measurements of chlorophyll indices, flavonols, anthocyanins, and NBI (Nitrogen Balance Index), thus allowing for a response before this fungus invades and damages the plant.