Plant Health Initiative

Working together against soybean rust

Producers, universities, industry and government create a practical, applied defense to fight a devastating disease

Soybeans are one of America’s most important row crops, contributing more than $19 billion to the U.S. economy. An internationally conceived, proactive management strategy has been developed to mount a practical, applied defense against a devastating fungal disease, soybean rust (SBR).

This monitoring and research effort is a unique partnership involving soybean producers, university specialists and researchers, industry and government agencies. Since 2004, cooperators have contributed tremendous amounts of expertise, facilities, personnel and research to stopping soybean rust from marching across North America.

By gathering forces, the partners have created a precision monitoring system, a coordinated education, information and training network, and a comprehensive research effort against SBR. They’ve equipped the soybean industry to fight off a major crop disaster.

The benefits of the SBR prevention and control program are clear:

• Farmers are realizing up to $300 million in savings every year by targeting crop protection only where it is needed.
• The soybean sector is keenly attuned to potential advances in SBR throughout the United States, Canada and Mexico.
• Research efforts are bringing together the top scientists for maximum coordination, advancement and education.
• Other important field crops can use this proven model and approach for problem solving efforts.

These achievements are made possible by a commitment to work together, pool resources and remain diligent. The current disease threat is closely monitored, while disease management tactics are researched through studies at numerous land grant institutions, and by industry. It’s a sustainable approach that keeps the soybean sector profitable, vibrant and productive.

 

The plan: Cooperation, coordination and diligence

Orange stakes mark selections in a soybean rust resistance trial at Quincy station.

The SBR disease-causing pathogen has been reported to occur on more than 150 legume species worldwide. Yet, even though the U.S. grows 75 million acres of soybeans, SBR has not taken a strong foothold. The SBR monitoring program keeps tabs on the disease and helps the industry to respond quickly, when and where SBR develops during critical times in the season. Studies by researchers in the network help determine what response should be taken, including fungicides to control the fungal spores and, soon, the use of resistant cultivars.

Growing conditions have been instrumental in the disease being stymied in North America. When SBR was first discovered in the U.S. in 2004, the subsequent weather was extremely dry in the south where the fungus overwinters. But lately that has changed; overwintering in 2009 has been seen in Alabama, Arkansas, Georgia and Louisiana. Continued monitoring and research is essential as this organism changes, adapts and gets a foothold.

“The disease annually overwinters somewhere in the southern USA, and we closely monitor the range and extent of overwintering,” says Prof. Don Hershman, University of Kentucky. “Whether it spreads into critical soybean acres of the country is mainly determined by weather and storm systems. Our job is to follow the disease where ever it is so we can make the most appropriate risk assessments to give producers.”

Realizing 75 research-years of study… in just four years

North Florida Research and Education Center in Qunicy, Florida is the headquarters of active research on soybean rust-resistant soybean varieties, fungicide trials, and soybean rust epidemiology.

The southern USA is the entry point and incubation center for many pests and diseases that affect the rest of the U.S., and Canada. And that means it’s also a natural place for research efforts which can address the problems when they arrive.

That has certainly been the case for SBR, and for the way it’s been researched at centers such as the University of Florida’s Quincy research station. It was not exclusively – or even particularly – a “Florida problem,” because the state doesn’t grow many soybeans. But University of Florida agricultural leaders recognized that if they worked together with the soybean industry, they could have a significant effect on the disease’s impact.

The University of Florida administration worked at a high level to ultimately help farmers. They committed a huge portion of the Quincy facility, personnel and research plots to SBR, a signal to the industry to get on board. Now, the Quincy-led research program has drawn every active plant pathologist in the U.S. and Canada with an interest in SBR into the program. University researchers from Florida, Illinois, Iowa, Ohio, Kentucky, Louisiana, Tennessee, South Dakota, Missouri, Arkansas and Ontario have also become involved. Much additional research on SBR has been conducted in other states as well, but most of the projects and researchers have some link to the Quincy facility.

As a result of the coordinated initiative – north working with the south, east working with the west, U.S. working with Canada -- an intensive 75 research-years of study have taken place in just four years at Quincy.

Researchers measure the effects of climatic conditions on the spread of rust.

Promising sources of SBR resistance have been identified. The impact of row width, canopy microclimate, moisture and temperature on disease development and spore release have been quantified. The efficacy of many fungicides, both for organic- and conventional production, have been put to the test. Separately, these results would have taken several decades to achieve. These discoveries underline how proactive research must continue as standard operating practice in disease management.

Researchers identified effective chemical control strategies. That led to labelling rust-related fungicides for soybeans, which are being incorporated in southern U.S. production systems. Some fungicides can protect plants from infection for up to five weeks.

The University of Florida Quincy had a vital role in producing a practical, applied management plan in a highly accelerated timeframe. Its role went beyond laboratory work – indeed, almost 500 people have now been trained on rust identification, too. And every year, an SBR research symposium at the Quincy station draws dozens of scientists, graduate students, industry personnel and farm organization representatives eager to exchange information and discover the latest advances and approaches to controlling SBR.

 

SBR disease prevention by the numbers

Several hundred people are involved in the sentinel plot system each season, and over 10,000 observations are uploaded to the PIPE website (www.sbrusa.net).

Across the soybean industry

• Up to $300 million savings each year since 2005 as a result of reduced pesticide applications
• 15 million hits on www.sbrusa.net (USDA-PIPE) —a nationwide, real-time monitoring and forecasting system.
• Thousands of personnel trained by extension services carried out in each state through field days and grower presentations.

Through concerted efforts at Quincy

• 33 scientists cooperated from 11 North American universities
• 15 agri-businesses from fertilizers, pesticides, application, and seed and genetics were involved in the research
• Almost 500 people trained on rust identification
• 23 published papers
• 38 scientific abstracts, posters, and proceedings publications

 

Advancements in the fight against SBR (highlighting major cooperators)

• Training for proper SBR identification
  (National Plant Diagnostic Network, Southern Plant Diagnostic Network, and North Central Soybean Research Program)
• Modelling and monitoring
  (with Penn State and Iowa State)
• Enhanced plant breeding for resistance
  (with USDA, Brazil, University of Illinois, and Iowa State)
• SBR biology and epidemiology
  (with North Central Soybean Research Program and University of Kentucky)
• Agricultural crisis management (with ipmPIPE)
• Preparation for incoming exotic disease (with USDA)
• Identification of sources of resistance
  (with USDA, Brazil, University of Illinois, and Iowa State)
• Mapping of Rpp genes (one is now cloned)
  (with USDA)
• Training for fungicide application – getting to the lower canopy
  (with University of Illinois and North Central Soybean Research Program)
• Fungicides labeled for use in the US
  (with North Central Extension and Research Activities 208 Committee)
• Enhanced disease management overall (with many cooperators)
• Spore mortality in sunlight
  (with Iowa State and North Central Soybean Research Program)
• New spore traps – increased efficiency and detection
  (with USDA and Louisiana State University)

 

Reaching across borders: Connecting with Canada

Ontario’s soybean sector is solidly behind Can-Am efforts to control diseases and pests. Field crops extension plant pathologist Albert Tenuta of the Ontario Ministry of Agriculture, Food and Rural Affairs personifies the multi-faceted commitment. To wit: Tenuta is a provincial government employee, but his office and some field plots are located on the University of Guelph’s Ridgetown campus, about 90 minutes from the Windsor-Detroit border. He works closely with his 14 OMAFRA field crop extension colleagues, as well as Agriculture and Agri-Food Canada, the farmer-based Ontario Soybean Growers, seed companies and crop protection companies as well as his counterparts from the U.S. (including having plots at the University of Florida Quincy research center).

The joint approach to soybean problem-solving began back in the late 1990s. North-central soybean researchers and program administrators from both sides of the border attending science symposia realized farmers’ fields shared common ills – Phytophthora root rot, white mold, soybean cyst nematode, brown stem rot, soybean viruses and more. They also realized their budgets were limited, and that by working together they could make human resources and research funding go further. It was an approach that resonated with grower organizations,

Cross-border cooperation is working, as shown by a recently completed NCSRP project led by Prof. Anne Dorrance, a plant pathology researcher with The Ohio State University. Tenuta, along with Terry Anderson at the federal research station in Harrow, Ontario, assisted in categorizing Phytophthora sojae pathotypes in the north-central U.S. and Ontario. These results will speed Phytophthora-resistant variety development and target soybean varieties best suited for specific regions, reducing grower losses to the disease. Similar partnerships are addressing other problems, such as aphids. .

But without question, the piece de resistance in cross-border cooperation is the united effort to deal with soybean rust, which Tenuta found in an Ontario sentinel plot in 2007. This comprehensive program has earned soybean rust a well-deserve reputation as the perhaps most defended-against plant disease ever. Extensive surveillance (including the Ontario Soybean Rust Coalition’s 30 sentinel plots) supports reams of pertinent information and educational material designed to help farmers identify, understand and treat the disease. Among the CDs, identification cards and manuals available is a 111-page magazine-like guide for using foliar fungicides to manage soybean rust. It’s a colorful, readable publication with contributions from a wide cross-section of researchers, and it’s proven extremely popular on both sides of the Canada-U.S. border.

 

Milestones for SBR identification and control

1999	USDA starts screening for ASR varieties, prompted by confirmation of ASR in South America
2000	USDA and crop protection companies increase fungicide testing in Africa, Brazil and Paraguay, where SBR is emerging
2002	Genetic evaluations begin at USDA level 3 containment facilities in Ft. Dietrich
	SBR response intensifies – extensive coordination begins among land grant universities, multi-state SBR committees, USDA, national and regional commodity groups, crop protection companies and spray equipment manufacturers.
2005	2005: National sentinel project launched. Quincy identified as SBR research hub; various research activities synthesized at Quincy.
2006	Emerging Plant Pathogen Center established.
2007	Monitoring efficiency increases as researchers develop more expertise in SRB disease
2008	More than 2,000 breeding lines and more advance varieties for rust resistance tested in the field, including a collection of lines from Canada. Experimental disease forecast models developed and tested to help growers determine when it’s necessary for fungicides to be applied in specific fields.
2009	Prevention and management program developed. Soybean industry now has the fungicides and knowledge to manage the disease, including a highly coordinated monitoring system.

 

Advancement and discovery of soybean rust

 

1902	Japan
	Pacific Rim
1951	Hawaii
	Central America and South America
2001	Paraguay
2002	Brazil and Argentina
2004	U.S. reports first case of ASR, in Baton Rouge, Louisiana. Also spreading into Columbia and Uruguay
2005	ASR spreads to nine U.S. states
2006	ASR discovered in 15 U.S. states.
2007	ASR in 19 states, as well as Ontario.
2009	ASR found overwintering in Alabama, Arkansas, Georgia and Louisiana.

 

Links

• Pest Information Platform for Extension and Education (PIPE)
• Using Foliar Fungicides to Manage SBR (read chapters online, or download)
• 2009 National Soybean Rust Symposium - conference website