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POSTERS: Host resistance screening

Assessing susceptibility of University of Florida southern highbush blueberry cultivars to bacterial wilt.
Deanna Bayo - University of Florida. David Norman- University of Florida MREC, Patricio Munoz- University of Florida, Philip Harmon- University of Florida

Blueberries are a high value crop in Florida, where our climate allows for an early harvest during an advantageous market window. Bacterial wilt of blueberry is caused by Ralstonia solanacearum and was first reported in 2012 in New Jersey on the cultivar ‘Bluetta.’ In 2016, bacterial wilt was detected in Florida on the southern highbush blueberry (SHB) cultivar ‘Arcadia.’ Since 2016, the disease has spread to farms throughout central Florida, and ‘Arcadia’ continues to be the cultivar in which bacterial wilt is most frequently detected. Developed by the University of Florida (UF), this cultivar is popular among growers for its large fruit size and good tolerance to leaf diseases. To help assess this new threat to Florida blueberry production, we screened cultivars that account for greater than 90% of planted acreage for susceptibility to bacterial wilt. Rooted cuttings of 13 SHB cultivars, ‘Bluetta,’ and one early ripening rabbiteye blueberry were wound inoculated with bacterial suspensions in the summer of 2017. Time from initial symptom development to death was recorded over a period of 8 months. The presence of R. solanacearum was confirmed when plants died, or at the close of the experiment. Frequency of disease detection varied significantly among cultivars, and Arcadia was in the most susceptible statistical grouping. The assay we developed may be useful for selecting less susceptible varieties to bacterial wilt in the UF blueberry breeding program.