Prussin, A. J., II, Li, Q., Malla, R., Ross, S. D., and Schmale, D. G., III. 2014. Monitoring the long-distance transport of Fusarium graminearum from field-scale sources of inoculum. Plant Dis. 98:504-511.The fungus Fusarium graminearum causes Fusarium head blight (FHB) of wheat. Little is known about dispersal of the fungus from field-scale sources of inoculum. We monitored the movement of a clonal isolate off: graminearum from a 3,716 m-(0.372 ha) source of inoculum over two field seasons. Ground-based collection devices were placed at distances of 0 (in the source), 100, 250, 500, 750, and 1,000 m from the center of the clonal sources of inoculum. Three polymorphic microsatellites were used to identify the released clone from 1,027 isolates (790 in 2011 and 237 in 2012) of the fungus. Results demonstrated that the recovery of the released clone decreased at greater distances from the source. The majority (87%, 152/175 in 2011; 77%, 74/96 in 2012) of the released clone was recaptured during the night (1900 to 0700). The released clone was recovered up to 750 m from the source. Recovery of the released clone followed a logisfic regression model and was significant (P < 0.041 for all slope term scenarios) as a function of distance from the source of inoculum. This work offers a means to experimentally determine the dispersal kemel of a plant pathogen, and could be integrated into management strategies for FHB.Many plant pathogens use the atmosphere to move over long distances (1,2), including Peronospora tabacina, causal agent of tobacco blue mold (4), Phakopsora pachyrhizi, causal agent of Asian soybean mst (4,21), and Puccinia graminis f sp. tritici, causal agent of wheat stem rust (40). The atmospheric transport of plant pathogens is broadly characterized by the aerobiological processes of hberation, horizontal transport, and deposifion (18). A detailed understanding of these processes is a prerequisite to the development of successful plant disease management strategies.Another important plant pathogen that utilizes the atmosphere for long-distance transport is Fusarium graminearum (synonym Gibberella zeae) (24,37). F. graminearum is a fungal plant pathogen that causes Fusarium head blight (FHB) of wheat and barley, which has resulted in more than $3 billion in crop losses in the United States over the past two decades (25,29,33). The fungus produces a mycotoxin known as deoxynivalenol (DON) that may contaminate food and feed and threaten the health of humans and livestock (38,41).The disease cycle of F. graminearum has been well studied (33). The fungus overwinters in crop debris (e.g., residues of wheat, com, and barley) from previous growing seasons (12). In the spring, perithecia develop on crop residues and forcibly discharge ascospores millimeter-scale distances (11,32,42,43). These ascospores have the potential to move over long distances by wind (24,36), and may infect fields in neighboring regions. Dill-Macky and Jones (10) found that FHB incidence and severity were highest when wheat followed a sus...