Monday, December 10, 2007 - 9:29 AM

The use of functional ecology indicators in assessing organic fungicide treatments for Asian soybean rust (Phakopsora pachyrhizi)

Alex M. Johnson,, Mark E. Whalon,, Daniel R. Nortman,, and Amy M. Hendricks, Michigan State University, Department of Entomology, B-11 Center for Integrated Plant Systems, East Lansing, MI

The threat of Asian Soybean Rust (ASR), Phakopsora pachyrhizi, is a continuing concern for organic soybean growers throughout the United States. Methods have been developed to test the efficacy of organic fungicides that might be used to control this pest, but it is unclear whether the addition of Rust fungicides will disrupt the sustainability of organic soybean production. This project uses principles of functional ecology to assess the impact of different fungicides on natural enemy and mite populations - providing inference to the overall impact on the field and surrounding ecosystems. Plots include two treatments: hydrogen peroxide and BalladTM (Bacillus pumilus) as well as an untreated control. Unbaited yellow sticky traps will be arranged in transect across the field and additional traps will be deployed along the boundary of the field. Traps will be deployed on average for 12 days during three different times of season and will then be assessed in the lab. Mite samples will also be taken from the plots. The Shannon diversity index will be used initially to determine relative species diversity. Grid data will provide information that can be analyzed using geographic information system (GIS) methods. Homogeneity of regression calculations will determine whether the treatments are statistically significantly different from one another and whether they outperform the control.