|Riley, T.D. - USDA-APHIS|
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: March 4, 2005
Publication Date: June 1, 2005
Citation: Gottwald, T.R., Riley, T.D. 2005. The effect of hurricanes and tropical storms on long distance spread of citrus canker. Phytopathology. 95:6S36. Technical Abstract: Asiatic citrus canker (ACC) is a serious disease of citrus that causes foliar and fruit lesions leading to extensive yield and quality losses. During Fall 2004, Florida experienced 3 hurricanes (Charlie, Francis, Jeanne) and one tropical storm (Ivan) whose paths crossed the majority of the commercial citrus industry. Prior to these storms, ACC infections were known to exist only in Dade, Broward, and Palm Beach Cos. in southeastern Florida. Following the storms, ACC outbreaks were discovered in four major areas, Orange/Osceola Cos., Lee Co., Hillsborough Co., and Treasure Coast=Indian River/St. Lucie/Martin Cos., the latter was the only area not previously detected with ACC. Disease gradients were calculated and associated with various storms. Survey and assessment of all outbreaks lead to the discovery of 15 infections (4 commercial and 11 residential) that predated the storms and served as inoculum sources for storm-related spread. Residential disease gradients ranged from 1-12.7 km; the most extensive in St. Lucie Co. which experienced direct hits by 2 category 2 hurricanes with > 193 kmh<sup>-1</sup> winds and one tropical storm. Commercial disease gradients extended from 1.4-19.3 km. All gradients may have been complicated by mechanical spread as well. These results are consistent with a previously calculated storm-related disease gradient of > 11.6 km in south Florida.