Phytopatological monitoring of Inonotus rickii and GPS-GIS applications, Rome, Italy

Plant disease management may be improved by collecting, storing, manipulating, analysing and displaying epidemiological information using a Geographic Information System (GIS), a useful tool to evaluate plant disease problems in a spatial context. In this study, GIS analysis was applied along with global positioning systems (GPS) to integrate field data-collected with the spatial distribution of the pathogen Inonotus rickii. This pathogen provokes a decay of sapwood/heartwood and cankers, determining a progressive crown dieback and structural weakness of the trees, therefore increasing risk of branch breaks and tree failures. It is widespread in tropical and subtropical countries and it has already been recorded in many areas in Rome on Acer negundo, Albizia julibrissin, Koelreuteria paniculata, Celtis australis and Platanus x acerifolia. A survey was carried out in different boulevards of A. negundo and A. julibrissin with the aim of evaluating disease symptoms such as sparse foliage, dead twigs and branches, wood decay and presence of fungal structures. In this survey, I. rickii was recorded also on Robinia pseudoacacia, which is a new host. The study allowed to obtain thematic maps showing the spatial distribution of all infected trees, as well as the presence of anamorph and/or teleomorph structures of the fungus. Moreover, a map representing the incidence of the pathogen in different boulevards was obtained. The usefulness of GIS analysis in studies aimed to support and refine management strategies for disease control in urban trees is discussed.