ASR, a disease caused by the fungus Phakopsora pachyrhizi, requires living host cells to survive. It can infect over 90 host species of legumes, such as kidney beans, chickpeas, and kudzu. When ASR infects soybeans, it causes the plants to lose their leaves prematurely, which reduces the size and number of the beans. In areas where the disease commonly occurs, up to 80 percent yield losses have been reported. Environmental factors are critical to the incidence and severity of ASR. Long periods of leaf wetness, high humidity, and temperatures between 60 and 80 degrees Fahrenheit are ideal for spore germination. About 7 days after plants are infected with ASR, small brown spots surrounded by yellow rings appear on the leaf’s upper surface (stage 1). Within 10 days, pustules form in the spots, primarily on the undersides of the leaves (stage 2). These pustules have raised centers that eventually break open to reveal masses of fungal spores, called urediniospores (stage 3). Pustules can produce urediniospores for about 3 weeks. When the wind blows, the spores are dispersed, spreading the infection to other fields. Once windborne, the spores can reportedly travel hundreds of miles within a single day. Figure 1 shows the progression of infection on a soybean plant. ASR was first detected in Japan in 1902. By 1934, the disease was found in several other Asian countries as well as Australia. In 1951, the disease was first reported on soybeans in India. The disease was confirmed, and widespread infestations occurred in several African countries in 1996. In 2001, ASR was found in Paraguay and was detected in Argentina the following year. By 2002 the disease was widespread throughout Paraguay and in some limited areas of Brazil. ASR was first discovered in the continental United States in Louisiana on November 9, 2004. Researchers believe the disease was carried to the United States by tropical storms. Figure 2 shows the pattern of ASR’s spread throughout the world. USDA has been following the path of the disease and planning for its introduction into the United States for several years. In May 2002, three USDA agencies—the Animal and Plant Health Inspection Service (APHIS), the Cooperative State Research, Education, and Extension Service (CSREES), and the Agricultural Research Service—together with the National Plant Board, industry, and several land grant universities formed the ad hoc Soybean Rust Committee. In addition, USDA established the National Plant Diagnostic Network to enable diagnosticians, state regulatory personnel, and first detectors to communicate images and methods of detection for ASR as well as other diseases in a timely manner. USDA determined that once ASR arrived in the United States it could not be eradicated because of its rapid transmission rate and an abundance of host species. Thus, it decided fungicides would be the primary means of managing ASR in the United States and Canada until researchers can develop acceptable soybean cultivars that are resistant to the disease. Although the disease has resulted in significant losses in yield and production in other countries, soybean growers have learned to successfully manage the disease by applying appropriate fungicides. However, the use of such fungicides increases the production costs associated with soybeans, which had typically required relatively little or no management in the United States. For example, during the 2003 to 2004 growing season, Brazilian growers spent close to $1 billion on fungicides to prevent and reduce the spread of the disease. In the United States, the costs of applying fungicides for ASR are estimated to range from $10 to $35 per acre for each application. The total cost of applying fungicides will depend on the number of acres treated. All pesticides, including fungicides, must be registered and labeled in accordance with EPA regulations in order for them to be sold or used in the United States. If emergency conditions exist, however, EPA can grant an emergency exemption to state and federal agencies that allows the unregistered use of the pesticide under section 18 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). EPA regulations require state and federal agencies to submit an application for emergency exemptions and set limits on the duration of those exemptions. Under the Federal Food, Drug, and Cosmetic Act, as amended by the Food Quality Protection Act, EPA sets tolerances for pesticides—the maximum residue levels of pesticides permitted on foods. Unlike its process for registering fungicides, EPA may grant an emergency exemption for the use of a fungicide before it sets a tolerance for that fungicide. Fungicides for ASR are classified as preventative or curative. Preventative fungicides, such as strobilurins, prevent fungi from successfully infecting and/or penetrating the host tissue of the plant, while curative fungicides, such as triazoles, inhibit or stop the development of infections that have already begun. In addition, some fungicides contain both preventative and curative chemicals. To properly manage ASR, growers must apply the right class of fungicides at the appropriate time and with proper equipment. Applying fungicides too early can increase production costs, and the fungicide could wear off by the time an infection actually occurs. However, if growers wait too long to apply the fungicide, the disease could progress to an untreatable stage, and some crop could be lost. In order for fungicides to be optimally effective, they must be applied to the whole plant and be placed as deeply into the canopy as possible because the disease usually begins in the lower canopy before traveling into the middle and upper canopies as the crop matures. Fungicides can be applied by ground sprayers or from the air. Aerial application is a viable alternative when rainfall makes the fields too muddy or when large amounts of soybean acreage need to be sprayed within a short time. In April 2004, USDA’s Economic Research Service (ERS) conducted a study to project the potential economic losses associated with various degrees of ASR infestation in the United States. ERS concluded that the extent of economic impacts from ASR will depend on the timing, location, spread, and severity of the disease as well as the response of growers, livestock producers, and consumers of agricultural commodities. For the first year of ASR’s establishment in the United States, ERS estimated that the expected value of net economic losses could range from $640 million to $1.3 billion, depending on the geographic extent and severity of the disease’s initial entry. When ASR was discovered in Louisiana in November 2004, it was too late in the crop year to damage 2004 soybean production. Since ASR must have a living host to survive the winter, USDA believed the disease could only successfully survive over the winter in the southernmost areas of the United States and would have to be reintroduced each year into more northern soybean-producing areas. Therefore, its arrival provided an early warning to USDA, growers, and industry, allowing them time to prepare strategies for minimizing the impact of the disease before the 2005 crop year. USDA’s development and implementation of a coordinated framework was instrumental in providing an effective response to ASR on soybeans in 2005. The framework includes (1) a surveillance and monitoring network, (2) a Web-based information system, (3) decision criteria for fungicide application, (4) predictive modeling, and (5) outreach for training, education, and information dissemination. The goal of the framework was to provide stakeholders with effective decision support for managing soybean rust during the 2005 growing season, and USDA was generally successful in doing so. However, inconsistencies in how researchers monitor, test, and report on the disease could lead to incomplete or inaccurate data and detract from the value of future prediction models. Furthermore, the success of the 2005 framework was due in part to the leadership of senior USDA officials, who were able to mount a national campaign. The transfer of operational responsibilities to a land grant university, under the direction of USDA, raises concerns about the department’s ability to maintain the level of coordination, cooperation, and national priority that was achieved in 2005 to address ASR. The early detection of ASR through the sentinel plot network—one of the key components of the surveillance and monitoring program—was effective, according to officials in 23 of the 25 states we surveyed. Sentinel plots—typically about 2,500 square feet of soybeans, other host plants, or a combination of the two—are planted a few weeks before the beginning of the growing season and serve as an advance warning of approaching ASR. In total, states monitored more than 1,000 sentinel plots in 2005. USDA and the North Central Soybean Research Program, in affiliation with the United Soybean Board, funded the sentinel plot network established under the framework. USDA provided about $800,000 for a total of 300 plots in the 31 soybean-producing states and an additional 20 plots in 4 other states that produce dry beans, such as navy beans and chick peas. (USDA plans to fund a similar number of sentinel plots in 2006.) The North Central Soybean Research Program and United Soybean Board provided approximately $390,000 for a total of 400 plots in 20 states (20 plots per state). In addition, some states established and monitored other plots during the growing season. Officials of the 31 states we surveyed provided data on the number of sentinel plots sponsored by USDA and others during 2005 (see fig. 3). State personnel monitored these plots throughout the growing season to determine the presence and severity of ASR. Within each state, a designated official entered the monitoring data from the plots into USDA’s ASR Web site, an online, real-time data system.