Check the USDA-PIPE website for Virginia's commentary and specific recommendations.

The rust fungus, Phakopsora pachyrhizi, that causes Asian soybean rust has caused serious crop losses for decades in the eastern hemisphere. During the 1990�s Asian soybean rust was identified in Hawaii and Africa. In 2001 it was found on soybeans in Paraguay, South America. Later it was identified in Argentina, Bolivia, Brazil, Paraguay, and Uruguay. In November 2004 Asian soybean rust was identified from soybeans in a research plot in Louisiana. Subsequently that year Asian soybean rust was identified in Alabama, Arkansas, Georgia, Florida, Mississippi, Missouri, South Carolina and Tennessee. See the Virginia Soybean Rust and Aphid Monitoring Program page for more historic info on movement of the soybean rust fungus.

Asian soybean rust requires a living host for survival. This makes survival of the fungus in areas with temperatures below freezing unlikely. However overwintering in areas with freezing temperature is possible if the fungal host is located in a microclimate that is more protected. For example, overwintering of Asian soybean rust did occur during the winter of 2005/2006 in Georgia where the fungus was found on kudzu located in protected urban locations.

Fungal rusts, such as Asian soybean rust, have spores that are readily windborne and able to move long distances by wind currents. These spores are produced prolifically in multiple cycles during the growing season when environmental conditions are favorable. These qualitites contribute to Asian soybean rust's potential for epidemic disease development and allow long-distance movement into new areas despite the fact that rust is unlikely to overwinter where freezing temperatures occur.

Conditions optimal for disease progress are moisture on the leaf surface from periods of 6 to 12 hours and temperatures from 59F to 82F, conditions typically experienced in Virginia during the soybean growing season.