Indiana Prepares for Asian Soybean RustG. Shaner2, S. Conley1, R. Martyn2, T.S. Abney2,3, A. Westphal2, D. Egel2, G. Ruhl2, and K. Rane2,

Dept. of Agronomy1, Dept. of Botany and Plant Pathology2, USDA-ARS3, Purdue University, West Lafayette, IN.

The Asian Soybean Rust Team:

Purdue Agronomy Dept: Shawn Conley, Ellsworth Christmas, Corey Gerber

Purdue Botany & Plant Pathology Dept: Gregory Shaner, Dan Egel, Andreas Westphal, Scott Abney, Karen Rane, Gail Ruhl, Fred Whitford, Ray Martyn, Amy Deitrich

Purdue Agriculture Economics Dept: Corrine Alexander, Craig Dobbins, Chris Hurt, George Patrick

Purdue Agriculture Communications Dept: Steven Leer, Kevin Smith, Russ Merzdorf

Indiana Soybean Board: Chris Novak, Jonathon Whiteman

Sentinel Plots:Each of Purdue's agricultural centers (PACs) as well as the Purdue Agronomy Center for Research and Education (ACRE) had a sentinel plot established in May 2005. These sites included soybean and forage legumes: alfalfa, annual lespedeza, birdsfoot trefoil, crownvetch, kura clover, red clover, sweet clover, and white clover. These plots were inspected regularly by the superintendent at each PAC and by the extension plant pathologist (Shaner) at ACRE. The legumes were planted for two purposes, first to determine if they were hosts for P. pachyrhizi (all except alfalfa are reported to be), and second to determine if the fungus could survive the winter on any hosts that retain green leaves over the winter. This year was the establishment year for these forage plots, and consequently they were not inspected for rust. The soybean plots were inspected weekly or biweekly.

In addition to sentinel plots at the Purdue agricultural centers, plots were established elsewhere around the state and scouted by county extension educators and other cooperators. Some of these plots were special plantings; others were simply demarcated areas in a grower's field. In all cases, an attempt was made to establish plots with a planting date somewhat ahead of the typical range for Indiana (often difficult because many farmers now plant early). In some cases, the first planting was lost to frost and the plot had to be replanted. Observers forwarded data periodically to Greg Shaner, who summarized the information and uploaded it to the USDA web site.

There are approximately 50 locations in Indiana where kudzu is established. Several of these were

Publications:In response to the threat of Asian soybean rust, Purdue University, in collaboration with the Indiana Soybean Board, developed Extension Publication ID-324, “Preparing for Asian Soybean Rust.” This all-inclusive publication covers in detail crop scouting, identification, sample submission, pathogen biology, management, and economic/crop insurance issues. Over 10,000 copies have been distributed free of charge to growers, applicators, extension educators, and agricultural service professionals.

Education and Outreach Monitoring and DiagnosisTraining SessionsApproximately 1,400 individuals (including operators on at least 3.1 million of the 5 million acres of soybeans in Indiana) received training through various meetings and workshops. The concept that soybean rust is manageable was a key component of these sessions. The Purdue University Diagnostic Training and Research Center conducted 5 hands-on training workshops in March 2005 for growers and consultants that focused on the management of Asian soybean rust. The topics at these workshops included first detector training on disease diagnosis, information about management of rust with foliar fungicides, and soybean response to rust. Purdue University invited Dr. Robert Klein from the University of Nebraska to present information and demonstrations on fungicide application technology. These workshops helped train 321 growers, extension educators, and agricultural professionals.

Indiana Sentinel Plots

examined early in the season. Leaves on kudzu do not develop much before soybean seedlings emerge, so these sites were not inspected regularly, given the absence of rust anywhere near Indiana. In the future, should rust be found closer to Indiana, sentinel plot scouting will be supplemented with kudzu scouting.

Based on our experience this year, there may be no need to plant soybean sentinel plots earlier than the main crop. Early planting can result in serious defoliation by the bean leaf beetle, and there is the risk of frost damage. It seems unlikely that rust will reach the Midwest early in the season, so planting in late April or early May should work well. For detection of rust late in the season, a second planting of a later maturity group might be useful.

Background photo by Scott Bauer, ARS/USDA

International soybean rust Researchers provide vital insight and visual resourcesLead soybean researchers from Brazil and Argentina were invited to Purdue in order to share their knowledge about soybean rust management. Initial visits coincided with confirmation of ASR in the U.S. and proved to be very educational for the Purdue Soybean Rust Team and other soybean interest groups.

•Alvaro Almeida, Ph.D., EMBRAPA SOJA, Londrina, Brazil

•Daniel Ploper, Ph.D., Tucuman Research Station, Argentina

•Tadashi Yorinori, Ph.D. - EMBRAPA SOJA, Londrina, Brazil

These collaborators provided practical information about soybean rust and its management. They also provided visual materials that we were able to incorporate into presentations.

The visiting scientists emphasized the importance of providing unified information about soybean rust to growers as quickly as possible, establishing a grower warning network based on soybean rust sentinel plot data, and encouraged team members to visit Brazil and view soybean rust before it became established in the U.S.

Throughout their presentations they consistently echoed the idea that “knowledge is power, especially when it comes to combating a serious new soybean disease”

Training was also provided to growers and consultants through a program entitled “Soybean Rust First Detector and Management Training” offered at six different locations throughout Indiana. This all-inclusive program covering field scouting, disease identification and control measures, was sponsored jointly by Purdue University and the Indiana Soybean Board. The program was designed to assist Indiana producers in developing a response plan for soybean rust as well as to train and register participants as National Plant Diagnostic Network (NPDN) first detectors for soybean rust. The day-long training consisted of topics including:

Diagnosis of Asian Soybean Rust samplesPreparations:As part of the National Plant Diagnostic Network’s efforts to monitor for soybean rust, the Purdue Plant and Pest Diagnostic Laboratory was chosen as one of three laboratories in the North Central Region to offer real-time PCR analysis to identify the pathogen. Laboratory personnel participated in two training sessions sponsored by NPDN and conducted at the USDA-APHIS facilities in Beltsville and Ft. Detrick, MD. The USDA-APHIS Cooperative Agriculture Pest Survey (CAPS) program provided funds to purchase a Cepheid Smartcycler, and a separate laboratory room was set up for real-time PCR procedures.

NPDN Soybean Rust Detection Scenario ExerciseIn March 2005, team members along with Indiana regulatory personnel participated in a soybean rust detection exercise organized by the National Plant Diagnostic Network. A photograph served as a suspect sample. Movement of the sample from grower, to the Plant & Pest Diagnostic Lab, to USDA-APHIS specialists for rust confirmation was tracked through the NPDN Scenario Exercise website. Communications about the potential sample and confirming diagnosis with the Indiana State Plant Regulatory Official (Dr. Robert Waltz) and USDA State Plant Health Director (Gary Simon) were also tracked on the website. The exercise was an excellent way to inform all concerned parties of the proper pathway for samples and communication of results when the first case of Asian soybean rust is found in Indiana.

Asian Soybean Rust Web Page:An Asian soybean rust web page was created on the Plant & Pest Diagnostic Lab web site in November 2004. This page was developed to provide up-to-date information to growers, industry representatives, and general public on a variety of topics including host plants for ASR, fungicides, training opportunities, as well as fact sheets, links, and news articles related to ASR. One of the unique features of this site is the “Quick Guide to Uromyces vs. Phakopsora” developed by Dr. Ian Thompson, former Associate Curator of the Arthur Rust Herbarium at Purdue University. A pictorial guide for identifying ASR, developed by Gail Ruhl and Karen Rane, is also available for download on the site. Since its inception, the P&PDL ASR page has received 12,000 hits.

Sample submission:The Indiana Soybean Board agreed to provide funding for diagnosis of any suspect soybean rust sample submitted to the P&PDL by Indiana soybean growers, crop consultants or other agribusiness clients. Sentinel plot samples were also submitted to the P&PDL. A form was developed to distinguish these submissions from other routine samples submitted to the laboratory. Samples were examined for symptoms and signs of ASR upon arrival, were then incubated under moist conditions and re-examined 24 hours later. We decided to rely on microscopic examination of leaf tissue rather than ELISA or real-time PCR testing, until the disease was detected in an adjacent state. As the 2005 season progressed,the primary location of ASR was far south of Indiana, and sample submissions were fewer than anticipated. Fifty samples were submitted to our laboratory for Asian soybean rust determination, and all samples were negative. The primary diseases detected on these samples were Septoria brown spot, frogeye leaf spot, bacterial blight, and downy mildew.

The programs, which included lunch, were offered free-of-charge thanks to the Indiana Soybean Board and check-off dollars. Attendees completing the NPDN pre- and post-tests were registered as NPDN soybean rust first detectors, received a personalized NPDN soybean rust first detector certificate and were placed on an e-mail list to receive soybean rust update information.

Many county extension offices sponsored meetings as part of the Private Applicator Recertification Program and soybean rust was the featured topic. Training was also provided to extension educators by IP video and to certified crop advisors during their annual conference.

•The NPDN mission and ag biosecurity •Monitoring for high risk pests (focus on soybean rust)

•Quality and secure sample submission •Disease cycle and diagnostics

•Fungicides •Drift management

•Spray technology •Economics

•Crop insurance •Agronomic implications

Yorinori

Soybean Rust Sample Packaging

Incubation of leaves in laboratory