Monday, December 11, 2006

Effect of organic fungicides on natural enemies in Michigan soybean production

Alex M. Johnson,, Mark E. Whalon,, Dan R. Nortman,, and Willye W. Byran, Michigan State University, Department of Entomology, B-11 Center for Intergrated Plant Systems, East Lansing, MI

Asian Soybean Rust (ASR), Phakopsora pachyrhizi, is a fungus that attacks soybeans and is a potential problem for organic soybean growers throughout the United States. The threat of this new pest has prompted researchers to test the efficacy of organic fungicides. Functional ecology measures have been previously shown to be accurate indicators of ecosystem disturbance in Michigan apple and cherry orchards. This project uses principles of functional ecology to assess the impact of the different fungicides on natural enemy and mite populations, providing inference to the overall impact on the field ecosystem. Treatments included fields treated with hydrogen peroxide, BalladTM (Bacillus pumilus) and an untreated control. Unbaited yellow sticky traps were deployed in three different treatments for periods of 18 days early, mid and late season, and then assessed in the lab. Mite samples were also taken from each plot. Both yellow sticky and mite sample results were compared between treatments to assess any differences.