By Daren Mueller, Department of Plant Pathology
Currently, soybean rust has been reported on kudzu in Alabama, Florida, Louisiana and Texas. Rust was also reported in three states (5 municipalities) in Mexico on yam bean and soybean. These have been destroyed or are no longer active, except for the recent find in Chiapas in extreme southern Mexico. Although soybean rust has been found this season in Texas, Louisiana and Mexico, predictive models suggest that soybean rust activity is behind last year’s pace because of drier conditions in Texas and parts of the southeast.
Figure 1. Current distribution of soybean rust in 2008 (last updated June 15, 2008)
Soybean rust scouting in sentinel plots across the U.S. creates information for the real-time USDA ipmPIPE Web site (http://sbr.ipmpipe.org). The sentinel plots system is sponsored by the North Central Soybean Research Program, the United Soybean Board, and the United States Department of Agriculture. These plots of soybean or kudzu stretch from Florida to Texas and up through the Midwest. In 2008, sentinel plots have been established in Mexico for the first time.
This spring, 20 sentinel plots (see map) have been established across Iowa. We will be monitoring fields in these counties with the help of several Iowa Soybean Rust Triage members and ten Iowa State University Research farm staff. To date, several leaf samples have come in and the only disease found is Septoria brown spot.
Figure 2. Counties with sentinel plots for soybean rust scouting in 2008