Duane Dailey Senior Writer 573-882-9181 DaileyD@missouri.edu June 10, 2005 Asian soybean rust... Missouri agronomists report weekly scouting trips, all negative, on USDA website map, with other states COLUMBIA, Mo. - Agronomists from the University of Missouri have begun scouting specific "sentinel fields" across the state for signs of Asian soybean rust. Reports from those soybean fields are posted on a national Web site map that will show the spread of the crop disease. Missouri's early detection network covers 35 fields across the state in areas of concentrated soybean production, said Bill Wiebold, University of Missouri Extension agronomist. MU regional extension specialists will scout those fields throughout the growing season. The soybean rust map is at http://www.sbrusa.net/. For now, sentinel fields will be checked at least once a week, Wiebold said. Agronomists will increase scouting to three times a week if rust is reported in Mississippi, Louisiana or other states to the south. Asian soybean rust cannot overwinter in Missouri because of freezing weather. For the disease to appear here, spores must be carried into the state on winds from infected fields in southern states. The national map in early June shows mostly green marks, which indicates fields have been scouted but no rust found. The map's only red dots-indicating confirmed infestations-are in Florida where soybean rust was found overwintering on Kudzu vines, an alternate host. Rust also was found in southern Georgia on soybean plants sprouted from spilled seed growing near grain bins. Those infected plants were eradicated. In Missouri, each cooperating extension agronomist has contacted at least one soybean producer to gain permission to monitor the bean fields. "Farmers from each corner of the state and throughout central Missouri are part of the network," Wiebold said. Any suspected infections will be checked by the University of Missouri Plant Diagnostic Clinic. Plant samples will be transported according to federal guidelines to the clinic in Columbia for confirmation by Simeon Wright, director. Regional agronomists also are responding to requests from producers who suspect they have found the disease. The field agronomists have been trained to identify Asian soybean rust symptoms by Laura Sweet, MU Extension plant pathologist, and Al Wrather, pathologist at the MU Delta Center, Portageville, Mo. The heaviest concentration of sentinel fields is in southeast Missouri. Two cases of Asian soybean rust were detected on soybean plants in the Bootheel just before frost in fall 2004. A rust infection requires extended periods of leaf wetness and high humidity to develop and spread, Wiebold said. Scouts will look first in sections of fields that are shaded by trees and that have reduced airflow. Weather conditions play a large part in the spread of the disease, said Pat Guinan, climatologist with the MU Commercial Agriculture program. "Weather patterns over the Midwest for much of May blocked airflow from the south," Guinan said. "Weather conditions, especially south winds, will be monitored." The national rust website is maintained by USDA Animal and Plant Health Inspection Service (APHIS). The state early-warning network is sponsored by the Missouri Soybean Merchandising Council. Details on soybean rust identification and management is on the MU website at http://agebb.missouri.edu/mgt/soyrust/index.htm. Source: Bill Wiebold (573) 882-0621; Pat Guinan (573) 882-5908 Return to Current News Releases College of Agriculture Food and Natural Resources AgEBB