The United Soybean Board and The Soybean Checkoff answer important questions about soybean rust.
In the United States, soybean rust was first detected in 2004 and has continued to spread to more states and counties. The soybean checkoff invests in projects that help identify and develop resistance to soybean rust.
As part of this ongoing research, the checkoff has developed a list of frequently asked questions to help inform the general public about soybean rust and its impact on fields nationwide.
Rust can be controlled using these rules: SCOUT. MONITOR. MANAGE.
It is disease caused by the fungus Phakopsora pachyrhizi. The disease causes lesions to appear on the plant leaves, leading to premature defoliation and yield losses. Soybean rust is spread by spores, which are transported over long distances by wind. Spores can also move short distances by adhering to clothing or other surfaces. No. Soybean rust was first observed in Japan in 1902, and by 1934, it was found throughout most of the Asian countries and Australia. Rust was identified in South America in 2001, and the first U.S. cases were discovered in November 2004. Before it was detected in South America, farmer-directors serving on the United Soybean Board (USB) began to invest soybean checkoff dollars in research to minimize the impact of the disease in case it entered U.S. soybean crops. Soybean rust has only been a consistent problem for some farmers in the South, since the disease has not spread to the Midwest early enough in the season to affect yields. Affected farmers have learned to manage the disease through careful scouting and monitoring the advance of rust into their area. Soybean rust has not been a big enough factor to affect soybean-planting intentions, which are driven primarily by soybean
prices and other production factors. Soybean rust is known to infect more than 95 plant species, including kudzu and legume crops, such as lima beans, black-eyed peas, kidney beans and green beans. Rust can overwinter on these species.
USDA estimated the U.S. soybean crop in 2007 produced 2.58 billion bushels, which is down from the 2006 record of almost 3.2 billion bushels. The 2007 soybean crop was worth nearly $27 billion. According to USDA’s March 2008 Prospective Plantings report, U.S. farmers intend to sow 74.8 million acres of soybeans in 2008, up from 63.6
million acres last year. There are no known human health concerns associated with soybean rust disease. It does not affect food safety or food quality. To manage this disease, farmers should carefully scout their fields, monitor for any soybean rust symptoms and apply preventive or curative fungicides, if needed. The U.S. Department of Agriculture’s (USDA) Economic Research Service estimates that the value of net economic losses could vary widely between $200 million and $2 billion, depending on the severity and extent of outbreaks. The large range reflects the uncertainty associated with rust, but even high-end figures are considered small relative to the total value of soybeans on production and consumption. The USDA-Pest Information Platform for Extension and Education (PIPE) early warning system for soybean rust, which has been funded by federal government and soybean checkoff funds, saved U.S. soybean farmers up to $207 million in 2007. This assumes 40 percent of the 2007 soybean acres monitored by USDA-PIPE not treated for soybean rust would have been sprayed with fungicides if the information available from a rust early warning system for U.S. soybean farmers was not in place. If these specialty beans are infected by soybean rust, legume crops may be affected, but probably not as severely as soybeans. There are fewer fungicides currently available to treat edible legume varieties. Soybean rust has been observed in experimental plots of specialty beans in the United States, but so far, it has not damaged commercial crops or affected yields in these crops. USDA’s Animal and Plant Health Inspection Service (APHIS) concluded that once soybean rust enters the United States, it would not be possible to eradicate due to multiple hosts and the breadth of geographical locations in which rust can overwinter. USDA’s ERS reports permanent overwintering of soybean rust is likely only in the southeastern United States. Some level of periodic outbreak could occur in the United States in any given year. University of Missouri specialists note that the severity of the disease could vary greatly from season to season. Weather conditions that promote movement of rust spores and weather conditions that favor development of the disease during the growing season will determine how severe soybean rust infestations are each year. Purdue University economist Chris Hurt says that any increase in soybean prices due to soybean rust could be felt in the livestock and commercial food industries. Soybean meal is used in poultry and swine feed, and increases in the price of meal could increase consumer prices for these meats. Consumer prices for margarine, cooking oils
and other food products that contain soybean oil could also be affected by an increase in soybean prices. If soybean rust is detected and identified in time, the disease can be managed with the proper application of fungicides. Information on available fungicides and their recommended applications is available through state extension services. Soybean rust can be managed with properly timed fungicide applications. Farmers should have a scouting program in place for soybean rust and should monitor the spread of soybean rust into their area on the USDA Integrated Pest Management Plant Information Platform for Extension (PIPE) Web site, www.sbrusa.net. Additional information and management tips can be found at stopsoybeanrust.com. An online fungicide guide to manage soybean rust can be found at http://oardc.osu.edu/soyrust/. Farmers can also consult local extension service experts or Certified Crop Advisors for information on recommended fungicides and application timing. Purdue University economist Chris Hunt says soybean growers who spray infected crops with fungicides could see increases in production costs of $25-35 per acre. The additional production costs will directly reduce farmers’ profitability. Depending on the severity of annual rust outbreaks, soybean producers may bear 60 percent to 70 percent of total losses, with U.S. consumers and poultry and livestock producers bearing the rest. The following is a list of sources of more information on soybean rust.
Sandy Miller Hays
Director
USDA Agricultural Research Service Information Staff;
Phone: 301.504.1636
E-mail: sandy.millerhays@ars.usda.gov
To get in touch with a USB farmer -leader please call
Karen Pfautsch or Mike Orso
USB Soybean Rust Communications
Contacts at Osborn & Barr Communications
888.235.4332
