Résumé
This work was addressed to study the relationships between landscape context and the incidence of three noxious organisms with different abilities to spread: coffee rust (Hemileia vastarix), coffee berry borer (Hypothenemus hampei) and the root-knot nematodes (Meloidogyne spp.). We analized these relationships at different spatial scales (radii 50-1500 m) in 50 agricultural landscapes of the Turrialba coffee region in Costa Rica, differing in structural complexity. We found positive correlations between coffee berry borer abundance and the coffee area percentage in the landscape. The correlation was strongest at a scale of 150 m. We also found positive correlations between coffee rust incidence and the pasture area in the landscape. The significance of this relationship peaked at the 300 m radius. We didn't find any significant correlation between coffee root-knot nematodes and landscape. These relationships can be interpreted according to the dispersal ability of the studied organisms. Coffee berry borer is specific to coffee and can fly only at short distances. Coffee rust is an airborne pathogen which is probably favoured by open spaces. Nematodes are almost immobile. We hypothesize that fragmenting coffee regions may help to reduce coffee berry borer dispersal. In contrast, fragmentation of coffee landscape by pasture may increase coffee rust dispersal. (Résumé d'auteur)