More to learn about soybean rust in the 2006 growing season

Questions remain on how destructive the disease will be and how it will affect soybean production areas of the Midwest.

“Although soybean rust developed slowly in the southeastern United States in 2005, the disease has the potential to be more damaging in 2006 as the number of over-wintering spores on kudzu in Florida and other frost-free areas increase,” said Layla E. Sconyers, Department of Plant Pathology, University of Georgia, Tifton, GA.

The absence of soybean rust in the Midwest during the 2005 growing season does not mean that the disease will remain confined to the Southeast in 2006. “It is difficult to determine whether soybean rust will have a significant impact on soybean production in the Midwest, since those areas have winter temperatures that are too cold for the fungus to over-winter,” Sconyers said.

For soybean rust to develop in those areas, spores must be blown in from over-wintering sites in the Southeastern U.S., Central America, South America, or the Caribbean Basin. In 2005, environmental conditions were conducive for disease development due to numerous hurricanes and tropical storms, but the concentration or viability of spores may not have been great enough for disease development in the Midwest.

“Based on the knowledge gained from this year and next, we will continue to refine forecast models, warning systems, and provide management programs tailored for the producer in each soybean-producing region in the United States,” Sconyers said. “With the information that has been collected to date, and the continued cooperation among state, federal, and private agencies observed in 2005, we have the potential to accomplish a tremendous amount of work in 2006,” she said.

More on the 2006 soybean rust outlook is available in this month’s APSnet feature article at http://www.apsnet.org/online/feature/sbr. APS is a non-profit, professional scientific organization. The research of the organization’s 5,000 worldwide members advances the understanding of the science of plant pathology and its application to plant health.