Asian soybean rust has been confirmed in soybean sentinel plots on the east side of Mobile Bay in Alabama. Alabama officials say growers in south and central Alabama shoudl strongly consider spraying immediately if their crop is at bloom or at a later reproductive stage.

”Waiting for the disease to show up in your field before initiating your spray program could result in significant yield losses,” said Ed Sikora, plant pathologist and soybean rust coordinator for Alabama. “Once an epidemic reaches 10 percent severity, a fungicide application may not be of much benefit.”

“The disease was detected in plants in soybean sentinel plots growing at the Gulf Coast Research and Extension Center in Fairhope,” Sikora said. Fairhope is in Baldwin County on the east side of Mobile Bay.

Dr. Arcenio Gutierrez-Estrada, a member of Sikora’s soybean rust surveillance team, spotted the suspect plants June 28 and collected samples from two plants showing symptoms of the disease in the sentinel plots. The disease was found on one plant already bearing full-size beans while the other plant was in the bloom stage.

“We do not know how far soybean rust has spread within the state,” Sikora said. “We have not observed the disease in any of the other soybean or kudzu sentinel plots scouted this week.” But , he said, the recent warm wet weather could foster soybean rust development. Moisture and temperatures in the 60 to 85 degree range are favorable for the rust pathogen to infect the plant.

Source: Auburn University soybean rust Web page.