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Poster: Epidemiology: Risk Assessment


Potential global distribution of blueberry twig blight (Diaporthe vaccinii) predicted by two species distribution modeling approaches.
A. VAN BRUGGEN (1), H. Narouei-Khandan (1), C. Harmon (1), P. Harmon (1), C. Gardi (2), I. Koufakis (2), W. van der Werf (3), J. West (4) (1) University of Florida, U.S.A.; (2) European Food Safety Authority, Italy; (3) Wageningen University, Netherlands;

Blueberry twig blight (Diaporthe vaccinii) is an endemic disease in parts of the USA and Canada. It has been detected in limited locations in Belarus, Chile, China, Europe and Russia, but was reported to be eradicated in Chile and most of Europe, where it is a quarantine organism. Models on the potential spread of D. vaccinii do not exist. Published data on its worldwide occurrence were inventoried and supplemented with data from the National Plant Diagnostic Network. Occurrence and long-term climate data were entered in the species distribution models MaxEnt and Multi-Model Framework. The models correctly predicted that the climate in central-eastern USA, the US and Canadian west coasts, Latvia, Belarus and western Russia would be conducive to blueberry twig blight. Large areas in Europe, Eastern Australia, New Zealand, and smaller areas in South America and East Asia also were predicted to be conducive. Precipitation in the driest quarter contributed most to the prediction, followed by mean annual temperature, with an optimum of 10°C. The potential impact of D. vaccinii in Europe and its potential spread to native Vaccinium species is unknown. The pathogen can be spread by natural and human-assisted means, and the risk of introduction, establishment and spread of D. vaccinii along different pathways, as well as potential impacts and the efficacy of risk reduction measures, will be assessed by the Plant Health Panel of the European Food Safety Authority.