Soybeans (Glycine max L.) are a major commodity crop grown on over 29 million hectare (72 million acres) in the United States. A large part of the cropland base in Iowa, 5 million hectare (11 to 13 million acres) annually, is devoted to soybean production. Although long term crop yield trends are upward, soybean yield increases have been more stagnant than corn, the common companion rotational crop, causing growers to question factors such as disease that might be slowing yield growth. In late 2004 Asian Soybean Rust (Phahopsora pachyrhizi) was detected in the United States. Because of the potential for yield loss as observed in other countries, grower concern has resulted in increased interest in this and other foliar leaf spot diseases that may be affecting yield. Midwestern U.S. agronomic row-crop growers are generally familiar and experienced with herbicide and insecticide application, but have very limited experiences in field application of fungicides. Growers customarily have existing sprayer equipment set up to apply systemic herbicides with relatively large droplets to reduce drift and carrier application rates of 94 to 14 3L/ha (10 to 15 gal/acre) to minimize water transported and maximize the range of application area covered by an individual tank.