ARS | Publication request: MANAGING SOYBEAN RUST: HOST RESISTANCE, AND CHEMICAL CONTROL

Submitted to: American Seed Trade Association Conference Proceedings
Publication Type: Proceedings/Symposium
Publication Acceptance Date: May 12, 2004
Publication Date: November 15, 2004
Citation: Miles, M.R., Hartman, G.L., Frederick, R.D. 2004. Managing soybean rust: host resistance, and chemical control. American Seed Trade Association Conference Proceedings; 2004.

Technical Abstract: Specific resistance to P. pachyrhizi is known and four single dominant genes have been identified. These four genes condition resistance to a limited set of rust isolates. Soybean lines with partial resistance in field evaluations have also been identified. Identification and utilization of partial resistance in breeding programs has been limited. Yield stability, or tolerance, refers to the strategy of selecting genotypes with high yield potential and less yield loss from soybean rust. Since the report of soybean rust in Hawaii in 1994, the USDA-ARS has renewed its support for soybean rust research in the U.S. With support coming from the United Soybean Board, part of the research focus has been to identify resistant germplasm. There are over 16,000 soybean accessions in the USDA Germplasm Collection located at the University of Illinois. These soybean accessions, along with commercial and public cultivars grown in the U.S., are being evaluated for resistance to P. pachyrhizi in the USDA-ARS FDWSRU Biosafety Level 3 Containment Greenhouses at Fort Detrick, MD. Many fungicides have been evaluated to control soybean rust. The most recent trials in Africa and South America have identified additional triazoles, (eg.tebuconazole and tetraconazole), as well as several strobularins and strobularin mixes including azoxystrobin, pyraclostrobin, pyraclostrobin + boscalid and trifloxystrobin + propiconazole. There are a total of three fungicides that are registered for use on soybean, labeled for soybean rust and are commercially viable. There has been a Section 18 Emergency Exemption request for seven compounds or mixtures of compounds submitted to the EPA by the Departments of Agriculture of Minnesota and South Dakota.