What areas of the U.S. are most at-risk to yield losses from soybean?
All soybean-growing areas of the U.S. are at risk with the most favorable weather conditions (based on 30-year averages) in the Mississippi delta region and the Midwest. In general, southern growing areas are at greater risk than northern areas because of the longer growing season, the warm humid climate that is favorable for rust development, and the presence of other hosts such as kudzu. Risk analyses indicate that P. pachyrhizi could cause yield losses of greater than 10% in any U.S. soybean-growing region, while in southeastern coastal states, losses up to 50% or more are possible. Of course this is all dependent on weather conditions during the growing season and the actual point where the pathogen overwinters.
