Potential global and regional geographic distribution of Phomopsis vaccinii on Vaccinium species projected by two species distribution models

Vaccinium twig blight (caused by Phomopsis vaccinii, teleomorph Diaporthe vaccinii) is a major endemic disease on blueberries and cranberries in the Eastern and Northwestern USA and Canada. It has also been found in Europe, Chile and China. Publications on its occurrence in the USA and Canada indicate that the pathogen is limited to cool climates. Published data on worldwide occurrence were inventoried and supplemented with National Plant Diagnostic Network (NPDN) data in the USA. These occurrence and long-term climate data were entered in the niche models MaxEnt and Multi-Model Framework to predict the potential global distribution of the disease. Precipitation in the driest quarter and mean annual temperature contributed most to the prediction. The results indicate that P. vaccinii is not limited to cool climates, although the optimal annual average temperature is 10 A degrees C according to the MaxEnt model. The models correctly predicted that the climate in the central and eastern USA and the west coast of the USA and Canada would be conducive to blueberry twig blight. Large areas in Europe, eastern Australia and New Zealand, and smaller areas in South America and East Asia would be conducive too. For the first time, the NPDN database was shown to be an important source of information for the prediction of the potential global distribution of a plant pathogen.