Detection of plant pathogenic fungal spores is currently limited to assays performed on the affected plant tissue.  Though sentinel crops are often used as “warning systems” for monitoring the presence and tracking movement of a particular fungal plant disease, an effective “earlier-warning” system would be advantageous as it would provide additional time for effective disease management planning and earlier fungicide application strategies to be applied.  A notional concept for detecting plant pathogenic fungal spores as part of an early warning crop protection system would be to detect and identify pathogenic spore aerosols prior to their infecting the crops.  To improve the chances of such a system to be effective, high-volume air sampling combined with sensitive bioassays could be applied.  To demonstrate this concept, preliminary experiments were conducted that examined the feasibility of collecting and detecting an aerosolized plant fungus.  Prior to the aerosol experiments, a polymerase chain reaction (PCR) assay was developed for Epicoccum nigum (E. purpurascens – ATCC #48203), which has a conidial spore size similar to the causative agent of Asian soybean rust, Phakopsora pachyrhizi.  Spores of the fungus were prepared and aerosolized into an aerosol wind tunnel, upon which they were sampled by three aerosol collectors sampling at rates in the range of 10 to 1000 liters of air per minute.  Upon analysis of the samples, only those coming from the high-volume sampler consistently resulted in positive PCR assays.  Though limited, these results demonstrate the potential utility of high-volume sampling combined with sensitive bioassay for detecting and identifying aerosolized fungal spores as part of an early warning crop disease monitoring system.