Active soybean rust infections have not yet been detected in the southern United States on kudzu or soybean. Soybean rust survives through the winter on kudzu, and freezing temperatures this winter and early spring killed back most of the kudzu in the south. Therefore the amount of overwintering soybean rust spores available to infect kudzu and soybean were greatly reduced. Although soybean rust has not yet been confirmed in the U.S., scouting efforts continue in southern states and it is likely that the disease will be detected in the coming weeks.

The fungicide Topguard (Fultriafol; Cheminova) has received an EPA Section 3 label for use on soybean in 2010, and should be available for use in Indiana later in the month. This means that a Section 18 Emergency Exemption EPA label is no longer needed to apply this fungicide for soybean rust management in Indiana. See this updated list of fungicides labeled for use on soybean rust.

Indiana will once again participate in the national sentinel plot system and will monitor 11 fields on a weekly basis for soybean diseases, including rust, beginning in June. Support for the monitoring program is provided by the Indiana Soybean Alliance. Weekly updates on soybean growth stages, crop condition, and disease observations will be posted online at the ipmPIPE website, visible by clicking on the state of Indiana on the national map. Producers are also able to track the movement of soybean rust at this website.

Indiana soybean producers can also subscribe to the Indiana soybean disease update list serve. This email alert service will provide convenient and timely updates on soybean disease monitoring in Indiana, and also provide information on fungicide spray applications if soybean rust reaches Indiana at a critical time during the growing season. Purdue University will continue to maintain a toll-free soybean disease hotline, which is updated weekly beginning in late June. The phone number is 866-458-RUST (7878). We will also provide updated commentary in the Pest&Crop newsletter as the season develops.

SOURCE: Purdue University.