Coffee fruit rot in Puerto Rico: distribution, ecology and associated fungi

Anthracnose of coffee fruits caused by Colletotrichum species is responsible for major losses in coffee production worldwide. In most coffee-producing countries, this disease has been present for many years. Recently coffee fruit rot (CFR), a disease complex of Colletotrichum spp. and Fusarium spp. as casual agents, was described in Puerto Rico but it has not yet been quantified. This study surveys incidence and severity of CFR, correlates it to elevation, cultivation methods (full sun, shade or intercalated with taller plants) and the presence of the coffee berry borer (CBB), and identifies rot-associated fungi. We found that CFR is present throughout Puerto Rico at varying levels and that environmental and cultivation factors are associated with CFR incidence and severity. Specifically, increased altitude and shade correlated with lower CFR incidence. In addition, fruits damaged by the CBB were found to have significantly more disease than undamaged fruits. Lastly, we isolated 7 fungal genera associated with CFR, the most prevalent being Colletotrichum and Fusarium. Overall, this study suggests that planting coffee at higher altitude under shade and controlling CBB can reduce CFR.