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

Authors: CARRASQUILLO, MAYLIN - UNIVERSITY OF PUERTO RICO; MARIÑO, YOBANA - UNIVERSITY OF PUERTO RICO; MEDINA, ANA - UNIVERSITY OF PUERTO RICO; SERRATO DIAZ, LUZ; BAYMAN, PAUL - UNIVERSITY OF PUERTO RICO

Submitted to: European Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/25/2023
Publication Date: 10/17/2023
Citation: Carrasquillo, M.Y., Mariño, Y.A., Medina, A.G., Serrato Diaz, L.M., Bayman, P. 2023. Coffee fruit rot in Puerto Rico: distribution, ecology and associated fungi. European Journal of Plant Pathology. 168: 527-540. https://doi.org/10.1007/s10658-023-02781-1.
DOI: https://doi.org/10.1007/s10658-023-02781-1

Interpretive Summary: Coffee fruit rot (CFR) is one of the most important diseases affecting coffee worldwide. This disease is well known in Africa as coffee berry disease (CBD). The disease is characterized by external necrosis and sunken dark brown spots on green or mature coffee fruits that eventually become mummified. In Puerto Rico, coffee fruit rot has been present for many years, but has yet to be quantified. This study surveyed incidence and severity of CFR, and correlated these to environmental parameters, cultivation methods (sun vs shade), presence of the coffee berry borer (CBB), and fruit rot-causing fungi. This study showed that CFR is present throughout Puerto Rico at varying altitudes and environmental and cultivation factors are associated with its incidence and severity. Specifically, increased altitude and shade significantly correlated with lower CFR disease incidence. In addition, fruits damaged by the CBB were found to have higher disease incidence than undamaged fruits. Coffee fruit rot was associated with seven fungal genera with Colletotrichum spp. and Fusarium spp. being the most prevalent suggesting that there is a microecosystem complex on the fruit surface and pulp of coffee fruits. This study is important because planting coffee at higher altitude under shade and controlling CBB can potentially reduce CFR incidence.

Technical Abstract: Coffee fruit rot (CFR) caused by fungi is responsible for major losses in coffee production worldwide. In Puerto Rico, as in most other coffee-producing countries, this disease has been present for many years, but has yet to be quantified. This study surveys incidence and severity of CFR, correlates it to environmental variables, cultivation methods (sun, shade or intercalated) and the presence of the coffee berry borer (CBB), and identifies rot-causing 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 slightly but significantly more disease than undamaged fruits. Lastly, we isolated 7 fungal genera associated with CFR, the most prevalent being Colletotrichum and Fusarium spp. Overall, this study suggests that planting coffee at higher altitude under shade and controlling CBB can reduce CFR. Our results also suggest a complex microecosystem on the surface and within coffee fruits which involves CBB and numerous fungi.