Hot Topics Archive

NCSRP 2008 Soybean Aphid Research Update Now Available

March 17, 2008

Written by Extension entomologists throughout the region, this 12-page, full-color publication is packed with reports on soybean aphid biological control, genetic resistance (aphid resistant varieties coming soon), aphid early-warning systems, revisiting the 250 threshold, and treatment recommendations.

Order your free print copy of Soybean Aphid Research Update 2008 from NCSRP by calling 1-800-383-1423. Orders for mailing within the U.S. only, please.

You can also download a copy or read online in pdf format.

Soybean Rust Field Training Offered at the Florida Quincy Research Center

April 29, 2008

A soybean rust short course will be offered again this year at the North Florida Research and Education Center in Quincy, Florida. Participants will receive hands-on training in field identification and scouting techniques for Asian soybean rust. The class will be held on August 12 followed by another half-day on August 13.

There is no registration fee for the class, which is sponsored by the North Central Soybean Research Program. Registration materials and the agenda are available on the short course website»

SCN cysts extracted from soil. To monitor the effectiveness of your SCN management program over several years, sample soil at the same point in the management program each time, such as after a year of resistant soybeans or a nonhost crop. Photo credit: Terry Niblack, University of Illinois

Monitoring the Effectiveness of SCN-Resistant Varieties is a Key Management Strategy

March 27, 2008

University of Illinois Nematologist Terry Niblack has found that nearly two-thirds of farmers plant SCN resistant varieties on more than 75 percent of their fields. She considers that to be a high level of awareness that planting resistant varieties is a good way to combat yield losses due to SCN. 

However, she has also found that fewer than a fourth actually test for SCN. According to Tim Todd, nematologist at Kansas State University, monitoring the SCN population density gives a grower good information on the effectiveness of a given resistant variety with the particular population of SCN that infests a particular field. It is also important, he says, to vary the resistance used so the SCN doesn’t adapt to a particular variety. A survey in 2005 showed most SCN resistant cultivars in Illinois had resistance derived from a single source, and further studies showed 70 percent of the SCN had adapted to that source at some level.

As researchers do their part to find new sources and improve SCN resistance, farmers should not be satisfied just knowing they plant a “resistant” variety. Instead, they should be vigilant and strategic: varying the resistant varieties they use and testing repeatedly to monitor their progress.
Read more about SCN in the March issue of the NCSRP eNewsletter»
Read more on sampling SCN to evaluate the success of a SCN management program»

2008 National Soybean Cyst Nematode Conference Highlights SCN Resistance and New Tactics for SCN Management

March 10, 2008

The soybean cyst nematode (SCN) is the most widespread, yield-limiting factor in soybean production in the U.S. Once present in a field, SCN can never be eliminated. However, SCN can be managed to minimize its reproduction and maximize crop yields. The 4th Annual National Soybean Cyst Nematode Conference, held on March 6-7, 2008 in Tampa, Florida, brought together SCN researchers and Extension workers from around the country to discuss the latest developments in SCN management, as well as economic losses due to SCN, disease interactions, uses and abuses of SCN resistance, genetics of resistance, genetics of virulence, and more.

The two-day conference, sponsored by the United Soybean Board and the North Central Soybean Research Program, was organized by the American Phytopathological Society (APS) and the Society of Nematologists. Summaries of the presentations will be found soon on the APS website.

Soybean Rust Fungicide Manual Now Updated and Available Online

January 23, 2008

The popular comprehensive reference guide Using Foliar Fungicides to Manage Soybean Rust has been recently updated with new information and several new chapters. Download the complete document or view the list of chapters to read online.

Developments in Soybean Rust Research Presented at the 2007 National Soybean Rust Symposium

December 17, 2007

Since the arrival of the soybean rust pathogen in North America just three years ago, there has been an unprecedented amount of collaboration among producers, industry, scientists, USDA ,extension staff, crop advisors, and soybean check-off organizations to understand Asian soybean rust and to mitigate it's impact on soybean production in the United States. The positive results of this effort was clear as leaders in soybean rust research and extension shared their experiences and research results on December 13-14 at the National Soybean Rust Symposium in Louisville, Kentucky.

USDA PIPE: Soybean Rust Maps

Notable achievements of this nationwide, grassroots effort are many. In these three years we now have a real-time tracking system for soybean rust (USDA PIPE ), and the sentinel plot system, spore tracking system, and climate-based epidemiological models that feed into it. More than 475 people were involved in the sentinel plot system in 2007, and 13,412 observations were uploaded to the PIPE website. This represents an enormous amount of cooperative work. Many of you reading this page were probably involved - thank you for your efforts! To know when and where rust is found, and if environmental conditions are present that will favor it, is key information for deciding when to spray and when to wait. If one considers how many acres might have been sprayed unnecessarily if none of this information was available, you can see the huge environmental benefit as well as money saved from this information network.

As for soybean rust control, the reports on fungicide trials held in two U.S. and four South American locations in 2007 were positive. Most fungicides tested were reported to be "very effective" in controlling Asian soybean rust. Only when disease pressure was very high did some products perform better than others. The researchers confirmed that good coverage into the mid- and lower canopy is critical, as well as the timing of the fungicide application — especially if soybeans are still in early growth stages.

The risk of fungicide resistance was also discussed, and there was some good news in this area as well. Although fungi can and do develop resistance to the triazole and strobilurin fungicides used for soybean rust, there are factors about the U.S. situation that helps lower the risk. One is that Phakopsora pachyrhizi, the soybean rust pathogen, does not overwinter in most soybean production areas of the U.S., and another is that only one or two, if any, sprays are needed each season.

The red-brown or "RB" type of lesion formed by some soybean varieties in response to infection by P. pachyrhizi may be a type of resistant reaction because fewer spores are produced in these lesions compared to the light tan type of lesions.

Ultimately, as with all rust diseases, it will be the employment of resistant soybean varieties that will provide the most effective and stable long-term control of Asian soybean rust, and progress continues to be made toward this goal. Soybean breeders and plant pathologists are now in their third year of field-testing resistant soybean germplasm in the U.S. This year they evaluated 703 soybean lines in seven different locations and reported a clear sorting of resistant reactions compared to susceptible soybean varieties. Several genes for resistance have been identified and named. The next step is to make the selections, and to cross the resistant germplasm with "elite parents"—- soybean varieties with the desired agronomic characteristics.

Asian soybean rust was found in 19 states and 301 counties (thought to be a conservative estimate) in 2007. Although disease pressure was high in some southern areas, notably Alabama, Louisiana, and Georgia, it was generally held in check by widespread freezing temperatures in the south in April that reduced the amount of spores, and also by the 2007 drought. The northernmost find in the U.S. was in Hancock County, Iowa in October, and by November it was also detected for the first time in Ontario, Canada. Heavy rainfall in the early summer in Texas, and enhanced southerly winds ("low-level jet winds") that lifted spores up and into the northern states was the explanation by climatologists as to how the spores reached these northern locations. Fortunately, that happened late in the season when the soybean crop would no longer be affected by rust. However, this very route is typical for the spread of wheat rust in the U.S. and can happen much earlier in the season in any given year, which is what soybean rust forecasters are watching for carefully.

This third annual National Rust Symposium was sponsored by the American Phytopathological Society with financial assistance from the North Central Soybean Research Program, the United Soybean Board and the Iowa Soybean Association. Abstracts and PowerPoint presentations can be found in pdf format on the Plant Management Network website.

This soybean variety test is in a field with pressure from brown stem rot. Photo credit: Craig Grau

Take Advantage of the Latest Soybean Performance Trials When Selecting Varieties for 2008

November 30, 2007

State extension soybean variety tests are one of your best sources of information on the performance of soybean varieties, including resistance to pests and diseases. The tests include the soybean varieties that seed companies feel have the best potential, plus popular entries from each university.

Results of the 2007 variety trials from each of the 12 North Central land-grant universities have just been published and can be read online»

Sample Soil Now for SCN

October 12, 2007

Sample after the corn harvest and before next soybean crop. Photo credit: ISU Soybean Cyst Nematode Lab

Soybean cyst nematode is one of the most important diseases of soybeans. Up to 30% yield loss can occur because plants are producing fewer pods than they should. Fall is an ideal time to check for SCN in the soil. Sample fields where soybeans will be grown in 2008, and before buying soybeans for next season. You may also want to sample fields where SCN infestation is suspected because of poor plant growth, and in those fields where sudden death syndrome (SDS) occurred, as SCN predisposes soybeans to SDS.

You probably already have the equipment you need for sampling soil for SCN. You'll use the same equipment you use for taking a soil sample for soil nutrient analysis: a soil probe, a bucket, and a plastic or plastic-lined soil bag.

Sample the top 6 to 8 inches of soil. Take cores from within the root zone or from within the interrow area. You'll want to take 10 to 20 cores in a 10 acre area. If the field is larger, break the field into 10 to 15 acre units and take 10 to 20 cores per unit. Use a zig-zag or M-pattern to collect the soil cores. No matter what sampling pattern you use, the more cores you take, the better the estimate of SCN population density across the field. SCN is tiny, it is not uniformly distributed and it doesn't move far on it's own. Therefore, SCN tends to be aggregated or clustered in fields and soil sample results tend to be highly variable. Read more about sampling for SCN in the fall »

If you find out you have SCN, don't panic. Although SCN is a serious soybean pest, it can be managed profitably. The North Central Research Program's Soybean Cyst Nematode Management Guide is one of many good resources that can help you with answers to frequently asked questions, recommendations, and information based on decades of research on soybean management in SCN-infested fields. Order your free print copy of the SCN Management Guide from NCSRP, or read online»

Late-season foliar symptoms of SDS. Photo credit: Dean Malvick, University of Minnesota

Late Season Disease Scouting Helps in Next Year's Planning

September 5, 2006

September is the time to scout for sudden death syndrome (SDS), brown stem rot (BSR), stem canker, and white mold. These are common soil-borne diseases that show up this time of year in the North Central region. Many states are reporting an increase in sudden death syndrome in particular.

If you find these diseases in a field, the information you gather this season will be useful to manage the disease in your next soybean crop. If you are unaware of their presence, they will continue to build up in the soil.

Foliar symptoms of late-season diseases look similar, and may also be confused with early maturity or drought. SDS may be mistaken for brown stem rot or stem canker because these diseases show similar leaf symptoms. It is important for growers and crop advisors to be able to distinguish between these diseases because the control measures are different.

A key distinguishing feature of SDS is that roots of affected plants are rotted, while root systems of plants affected by BSR or stem canker remain healthy. SDS-infected plants are easily pulled out of the ground because the taproots and lateral rots have deteriorated. Symptoms present on both the leaves and roots is diagnostic for SDS (Table 1).

Table 1. Comparison of the signs and symptoms of brown stem rot, sudden death syndrome, and stem canker.

Check the USDA PIPE site regularly throughout the growing season.

Soybean Rust Found in Northern Oklahoma

August 8, 2007

The USDA PIPE website has reported soybean rust in Tulsa County, Okalhoma in a sentinel plot. This is the farthest north the disease has been found in 2007. Officials in Oklahoma, Texas, Louisiana, and southwestern Arkansas also report soybean rust in commercial soybean fields.

Weather conditions have been favorable for rust development in many parts of the south and to the states just north of the gulf states. However, the risk of a serious outbreak of rust in the north-central region is still predicted to be low. Soybean rust sentinel plots continue to be monitored extensively throughout the region.

Use a shovel to dig 6 to 8 inches away from the plant stem and gently shake excess soil from the root system. Photo credit: University of Wisconsin

Now is a Good Time to Check Soybean Roots for Soybean Cyst Nematodes

July 19, 2007

Soybean cyst nematode (SCN) is one of the most important diseases of soybeans. Many farmers don't know their fields are infested with SCN—- you often can't tell SCN is there from looking at the field. Yet up 30% yield loss can occur because plants are producing fewer pods than they should.

Observation of adult females and cysts on the roots of soybean plants is the most accurate way to diagnose SCN infestation.
Adult SCN females will be white or light yellow, and lemon-shaped. They will be a lot smaller than the nitrogen-fixing nodules, about the size of the period at the end of a printed sentence. Read more about SCN sampling»
Read more about SCN»

Brazil to Halt Planting in Three States to Stop Spread of Asian Rust

June 25, 2007

The U.S. Soybean Export Council has reported that Brazil is again set to ban planting of winter soybeans in three center-west states from June 15 for three months to prevent the spread of Asian soybean rust. The ban on planting comes based on advice from the government's agricultural research agency Embrapa and is applicable in the states of Mato Grosso, Mato Grosso do Sul, and Goias. Farmers who ignore the winter planting ban may have their crops destroyed or be fined. Despite the ban on last year's winter planting, Embrapa estimated that the disease resulted in the loss of 2.67 million tons of soybeans this year, similar to losses in the previous harvest.

According to Embrapa, Brazilian farmers spent $2.2 billion, mostly on fungicides, in an attempt to control the disease, but experts said that sprays were often used at the wrong time. Since the disease reached Brazil in 2001-02, the country has lost an estimated $7.7 billion in soybean output and expenditure on crop protection.

Parasitism of the soybean aphid by a beneficial wasp. Photo credit: University of Wisconsin

Soybean Aphid Biological Control … An Exotic Approach

Dr. Chris DiFonzo, Michigan State University
June 1, 2007

This season marks the seventh year since the discovery of soybean aphid in North America. This year also marks the first introduction of an exotic natural enemy of the soybean aphid.

A tremendous amount of research was done to make this release possible. Funding came from a variety of sources including a multi-state USDA project, as well as soybean growers themselves through state and regional (North Central Soybean Research Program) commodity check-off programs. The multi-state project includes entomologists from Iowa State University, Michigan State University, University of Minnesota, University of Wisconsin, and the USDA...read more»

USDA Soybean Rust and Aphid Maps

USDA Pest Information for Extension and Education Website Expands

June 21,2007

The soybean rust sentinel plot system is again in place for 2007 across the entire soybean-growing area of the United States. The results from scouting these plots are entered into the USDA Pest Information Platform for Extension and Education (PIPE) website at www.sbrusa.net.

Many growers and advisors are familiar with the format of the PIPE map, with the green and red spots. The green spots represent counties where sentinel plots have been scouted, but no soybean rust was found. The red spots represent counties where sentinel plots have been scouted and soybean rust was found. By clicking on an individual state, you can read a summary of findings and advisories written by extension specialists for soybean growers in your state.

The soybean aphid (Aphis glycines) has now been added to the system – check the drop-down menu in the upper right corner of the PIPE homepage. Population levels of the soybean aphid will be monitored during the 2007 growing season and the results posted on the aphid map. If PIPE proves to be a useful way to provide information on an insect pest, other crops and pests may be added to PIPE in the future.

Bean leaf beetle Photo credit: Kevin Black

Monitor Bean Leaf Beetle Activity

May 23, 2007

Bean leaf beetles have begun to emerge in the region. The Iowa ICM newsletter reported winter mortality estimates from 88-92% in northern Iowa, to about 60% in southern Iowa. The Wisconsin Pest Bulletin calculated beetle mortality using two different models and reported 36-60% in 12 Wisconsin localities, to 60-100% mortality with the second model.

Once soybeans begin to emerge in an area, bean leaf beetles will quickly leave alfalfa fields, wild legumes, and clovers, and will concentrate on soybean. Fields planted earliest in an area are most at risk for high populations of the beetle. Concentrate initial scouting activities in these early-planted fields.

Bean leaf beetles feed on young, new tissue and can cause noticeable defoliation on seedlings. Fortunately, soybean plants are quite resilient in terms of the amount of defoliation that is tolerated: up to 40 per cent leaf area defoliation in the vegetative stages. Therefore, feeding by overwintered and first-generation beetles on soybean leaves seldom results in economic yield losses because the seedlings often recover...read more»

Soybean Producers Help Advance Soybean Genomics Research

May 6, 2007

The United Soybean Board recently granted more than $1million to United States Department of Agriculture (USDA) scientists to continue work on the soybean genome—the sequence of DNA that forms genes in the soybean plant. USDA scientists, together with the Department of Energy, have decoded about half of the soybean genome to date...read more»

Milestone in Soybean Aphid Biological Control

April 11, 2007

NCSRP researchers received the good news today that the USDA has granted a release permit for Binodoxys communis, a natural enemy of the soybean aphid. Several states (IN, IA, MN, WI, SD) are planning releases of the parasitoid this summer following federal and state permitting. A release permit for Minnesota has been granted and the other states are in the process of obtaining permision. This is an important milestone for soybean researchers and producers in the development of a long-term management strategy for the soybean aphid.

USDA Soybean Rust Maps

Bob O’Neil, Purdue University and director of the Soybean Aphid Biological Control project, thanks everyone who made this happen, including NCSRP, USDA-RAMP, the Minnesota Soybean Research and Promotion Council, and the Minnesota Agricultural Experiment Station for support, those researchers who collected in Asia and worked through the quarantine process, and George Heimpel, University of Minnesota, who worked with the USDA during the review process. You can read more about soybean aphid parasitoids and aphid biological control at the SABC website.

Asian Soybean Rust Confirmed on Soybean Leaf Submitted to Iowa State University

March 15, 2007

AMES, Iowa - Asian soybean rust has never been identified in an Iowa field since the disease was reported in the continental United States in November 2004.

However, the disease now was conclusively identified on soybean plant tissue that was submitted to the Iowa Soybean Rust Team last week. This soybean residue is reported to have been recovered from a bin of soybeans produced in Iowa in 2006. Efforts are underway to identify other remnant leaves that may show symptoms and signs of the disease in order to discern details of this event.

The fungus and the spores that cause the disease cannot survive without green leaf tissue and will die during Iowa winters. The recently discovered rust fungus does not pose a risk of infection for the 2007 growing season in Iowa. Read more»

Researchers Predicting Aphid Hot Spots

February 15, 2007

You’ve probably heard that university entomologists are predicting high aphid populations in some areas of the Upper Midwest this year. Growers in northern Indiana and Illinois, in particular, may see record aphid levels. These predictions are based on 40 suction traps that collect migrating aphids during the summer and fall. Unfortunately, the number of aphids captured last fall while migrating back to buckthorn was higher than ever in some locations.

Measuring the migrants
When the number of fall migrants is considerable, it indicates high levels of aphids overwintering – and a potential problem the following spring when soybeans emerge. Traps in Illinois have been running since 2001, so scientists have seen this trend in action three times. In the fall of 2002, the number of migrating aphids was very high, and 2003 turned out to be a nasty year for aphids. We saw the same pattern again in the fall of 2004, and aphid populations exploded in 2005. In fall 2006, researchers again recorded significantly higher numbers of migrating aphids in some spots.

Scientists caution that just because one trap count is high, it doesn’t mean every farmer in the Midwest needs to stock up on insecticides. Rather, a high trap count in your area may indicate a localized outbreak. For example, two of five Minnesota traps captured a lot of aphids in 2005, and in 2006, there were aphid outbreaks in those two areas.

Suction trap technology
The suction trap network began in Illinois, and has since expanded to 10 states in the North Central Region. The traps are basically big tubes roughly 25 feet tall – high enough to catch winged, migrating aphids. At the base of each tube is a jar filled with preserving fluid. Fans suck aphids into the tube, and aphids are preserved in the jar. Every week, researchers replace the jars and count the number of soybean aphids. Results are reported on the Regional Soybean Aphid Suction Trap Network, allowing entomologists to track soybean aphids. The project is funded by the North Central Soybean Research Program and several state soybean associations.

NSCRP's Research Initiatives Include Soybean Aphid, Rust, and New Sources of Resistance to SCN

February 3, 2007

According to Gregg Fujan, president of the NCSRP Board of Directors, reducing yield loss from soybean aphids is a top priority. Researchers will continue to refine management strategies, including the identification of natural predators that can be used to suppress the aphid population. Aphid researchers will also be operating a regional suction trap network to collect soybean aphid data to correlate with field populations, and to predict following-season population densities.

USDA Soybean Rust Maps

Asian soybean rust continues to be a top priority. NCSRP's partnership with the Quincy Research Station at the University of Florida enables researchers to conduct research where rust is most likely to show up every year. NCSRP will continue a partnership with USB to sponsor the sentinel plot program in the 2007 season. Information from the sentinel plots is mapped and posted at the USDA Public Soybean Rust Mapping Site.

NCSRP continues to invest heavily in research to mitigate losses caused by Phytophthora root and stem rot and by soybean cyst nematode, the two top yield-reducing diseases in the region. Both initiatives will focus on evaluating and developing new sources of resistance for plant breeders.

Emerging soybean viruses, identification of soybean varieties with high SDS resistance, and breeding and management efforts to overcome effects of iron deficiency chlorosis are also top priorities for North Central researchers. Results of the research will be posted on this website throughout the year. Read more»
PDF version of NCSRP's Research Initiatives»

Managing Soybean Aphids in 2007—How Will Biological Control Contribute?

February 13, 2007

A reminder that on March 6, 2007, entomologists from throughout the Midwest will conduct a short course on management of soybean aphids in 2007, with emphasis on biological control and conservation of natural enemies. Experts from several states will deliver the short course via distance education technology to sites in Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. Mark your calendars for March 6, 2007, from 8:00 a.m. to 12:00 noon (CDT), with audience interaction and feedback from 12:00 noon to 12:30 p.m.
View program»

Take Advantage of the Latest Soybean Performance Trials When Selecting Varieties for 2007

November 28, 2007

State extension soybean variety tests are one of your best sources of information on how specific varieties perform in different areas of the region. The tests include varieties which seed companies feel have the best potential, plus popular entries from each university. Results of the 2006 variety trials from each of the twelve North Central land-grant universities have just been published in print form, and can also be read online»

December Issue of the NCSRP E-Newsletter is Online

December 27, 2006

Reports on the recent symposium on Sudden Death Syndrome, the National Soybean Rust Symposium, SCN surveys, and more»

Soybean Rust Research Trials in Full Swing at Quincy Research Station

September 25, 2006

The research collaboration between NCSRP scientists and personnel at the University of Florida, Quincy Research Station is now in full swing, with natural rust epidemics providing a location for practical, in-field research. Rust is currently developing very rapidly in the North Florida Research and Education Center, and the NCSRP funding of the station has made it possible for Midwestern researchers to go down to Florida and study rust firsthand.

If you visited the center today you would find 22 acres of trials on host resistance, fungicide application strategies, epidemiology studies and much more. In one part of the center, an Illinois scientist has planted 50 different legumes native to North America or cultivated as commercial crops, to see if the plants are susceptible to rust under natural conditions. Throughout the season, over 130 different soybean rust fungicide trials have been or will be conducted at the NFREC. The center was host to 50 people from over 12 states who participated in the second annual rust training course this summer.

The research and extension National Committee on Soybean Rust will meet at NFREC-Quincy on October 25 and 26 to review 2006 research results. About 40 extension agents, researchers, and administrators are expected to attend. Results will also be shared at the National Soybean Rust Symposium sponsored by the American Phytopathological Society on November 29 - December 1 in St. Louis, MO. Expect to hear much more about the Quincy rust research at soybean extension meetings this fall and winter.

New Website for Soybean Aphid Biological Control is Launched

October 31, 2006

In 2005, a group of 14 research entomologists from five North Central states and the USDA received funding from NCSRP to conduct research on importation biological control of the soybean aphid. Importation biological control is a pest control method that adds new natural enemies from the pest's homeland, resulting in pest levels below economic thresholds.

The soybean aphid is dramatically less damaging in its native areas of Asia because of the presence of several beneficial insects not present in the United States. The group is already deep in research to identify these aphid natural enemies and to determine the potential for their establishment as a stable method of soybean aphid control in the Midwest. At the new Soybean Aphid Biological Control website you will find background information on biological control in general, and biological control of the soybean aphid in particular. You can also track the progress of the importation biological control project.

Importation biological control has been used to control insect pests for over 120 years. In the Midwest, importation biological control has successfully controlled exotic pests such the alfalfa weevil and alfalfa blotch leafminer in alfalfa, and the cereal leaf beetle in small grains. Importation biological control can be used as a "stand alone" approach or it can be integrated into a larger pest management strategy.

The program is a collaborative effort of research and extension entomologists at Purdue University, University of Illinois, Illinois Natural History Survey, Iowa State University, Michigan State University, University of Minnesota, USDA/ARS, and the University of Wisconsin.

Late Season Spread of Asian Soybean Rust Reaches the North Central Region

October 19, 2006

On October 18, Indiana announced the first soybean rust occurrence in the state. First reports of rust infection were also confirmed in Missouri and in southern Illinois. As of today, the USDA National Soybean Rust Commentary reported that rust infections have been found this year's soybeans in 15 states: AL, AR, FL, GA, IL, IN, KY, LA, MO, MS, NC, SC, TN, TX,and VA.

At this point in the season, soybean harvest is well under way across theNorth Central region and many areas have experienced a hard frost. Soybean rust will not impact yield, and management strategies are not necessary.

However, these finds are of great importance to the soybean rust predictive models. Rust epidemiologists are looking at weather patterns in late September which suggest that viable rust spores traveled over 500 miles from the lower Mississippi Delta to begin the infections found in Kentucky, Illinois, and Indiana about two weeks later. Rust workers in southern areas of the Midwest are making a great effort to know the extent of infection in the region until there are no soybean leaves in which the rust can survive. Unlike the 2005 season, more soybean rust finds are occurring up the Mississippi River Valley from apparent outbreaks in Louisiana.

Plant pathologist Greg Shaner, in his latest Indiana State Soybean Rust Update, points out that the arrival of rust in Indiana and other parts of the region will not impact next year's crop. This is because the soybean rust fungus can only grow and produce spores in living host plants — it can't survive in crop residue or seed. So once hard frost kills off volunteer plants, the pathogen will be completely eradicated from the region. Each year the fungus must once again migrate north from its over-wintering sites, regardless of how far north the disease progressed in the previous season.

Soybean infected with BPMV. Photo: Palle Pedersen, ISU

A Step Forward Toward Control of Disease Caused by Bean Pod Mottle Virus – First Identification of Field Tolerance

August 16, 2006

In a cooperative program funded by the NCSRP, Wisconsin Soybean Marketing Board, and the Iowa Soybean Association, researchers in WI and IA have made progress in understanding and quantifying field tolerance to BPMV and other viruses in soybean. With a certain level of field tolerance, a soybean plant is still able to produce a reasonable yield and decent seed quality in the presence of virus disease...read more»

Late Season Disease Scouting Helps in Next Year's Planning

September 6, 2006

Late-season foliar symptoms of SDS. Photo credit: Dean Malvick, University of Minnesota

September is the time to scout for sudden death syndrome (SDS), brown stem rot (BSR), stem canker, and white mold. These are common and potentially yield-threatening soil-borne diseases that show up this time of year in the north central region. Many states are reporting an increase in sudden death syndrome in particular.

If you find these diseases in any field, the information you gather this season will be useful to manage the disease in your next soybean crop. If you are unaware of their presence, they will continue to build up in the soil.

Foliar symptoms of late-season diseases look similar, and may also be confused with early maturity or drought. SDS may be mistaken for brown stem rot or stem canker because these diseases show similar leaf symptoms. It is important for growers and crop advisors to be able to distinguish between these diseases because the control measures are different.

A key distinguishing feature of SDS is that roots of affected plants are rotted, while root systems of plants affected by BSR or stem canker remain healthy. SDS-infected plants are easily pulled out of the ground because the taproots and lateral rots have deteriorated. Symptoms present on both the leaves and roots is diagnostic for SDS (Table 1).

Table 1. Comparison of the signs and symptoms of brown stem rot, sudden death syndrome, and stem canker.

USDA Soybean Rust Maps

A Two-Year Cycle for Soybean Aphid

June 23, 2006

Other than in Minnesota - where there is an abundance of buckthorn along the Mississippi River Flyway, which provides an ideal overwintering spot - aphids commonly appear every other year. "We think this two-year cycle is due to aphids' natural enemies, which include ladybird beetles (not only the multicolored Asian lady beetle, but several species of native ladybugs), fungi, green and brown lace wings, nabids, syrphids (also known as flower flies or hover flies) and the insidious flower bug," says David Ragsdale, University of Minnesota entomologist and head of NCSRP's soybean aphid research team . "It's the insidious flower bug that's doing such a good job of keeping aphid populations in check throughout Indiana."

Update on NCSRP Soybean Aphid Research

June 23, 2006

Soybean aphids

In the few years since the soybean aphid was first detected in North America, checkoff-funded researchers have developed good basic IPM tools, like the 250 treatment threshold and knowing which insecticides are effective in the field. "The next steps are harder and they take longer, such as developing resistant lines, assessing the benefits of native enemies and establishing exotic natural enemies", says Dr. David Ragsdale, University of Minnesota entomologist and head of NCSRP's soybean aphid research team. "Once that's done, our next challenge will be integrating resistant plants, natural enemies and biological controls into an advanced IPM system for growers". Ragsdale's best guess for when growers can get their hands on resistant varieties: "Possibly in two to three years there will be enough seed for commercial production of varieties adapted to the North Central region. We're getting close." Read more about soybean aphid IPM in the June PHI e-newsletter»

Soybean Rust Website Expands to Include Soybean Aphids

The USDA Soybean Rust website has a new feature this year: maps for the soybean aphid.

To view the aphid maps, go to the drop-down menu in the top right corner and select Soybean Aphid. Two maps appear on the right side of the screen. The top map is Soybean Aphid Observations, which shows soybean aphid detections from sentinel plots in each state. The color of the dots on the aphid map reflects the number of aphids. The second map is the Soybean Aphid State Update which provides commentary by state specialists.

A note of caution about the soybean aphid maps: entomologists in the North Central region agree the maps should not be used to make spray decisions in individual fields. This is different from how the rust maps are used. Detections of rust in an area can be used to help to time preventative fungicide applications in individual fields. In contrast, use the soybean aphid maps to get information about aphid populations in general, but do not use the maps to make a decision about whether or not to treat your own fields. Soybean aphid populations differ dramatically from field to field during an outbreak, and decisions on the optimal timing to protect yield must by made on a field-by-field basis. View USDA maps»

Monitor the Performance of Phytophtora-Resistant Varieties

July 21, 2006

Stem lesions are diagnostic of infection by P. sojae.

Warm soil and periodic rains at weekly intervals are ideal conditions for Phytophthora diseases. In the seedling stage, the fungus causes damping-off and seedling rots. In mid-summer, Phytophthora sojae can continue to infect soybeans, causing stem rot or chronic root rot. When the fungus is present, spores are released at every flooding or soil saturation event.

Variety selection is the key for managing Phytophthora diseases. Many soybean varieties marketed in the North Central region have resistance genes (Rps genes) for Phytophthora. The most common Rps genes are Rps1a, Rps1c, Rps1k, and Rps3a. Growers should monitor the performance of the resistance package of the soybean varieties they choose. When optimum disease conditions develop in mid-summer, scout those areas of the fields for signs of Phytophthora. If a large number of plants with Phytophthora stem rot or root rot are found, be aware of this, and choose varieties with a different Rps gene, or combination of genes, and higher levels of partial resistance (field tolerance) for next season. Read more about Phytophthora»

Update from the USDA National Soybean Rust Commentary

June 22, 2006

Florida officials have reported soybean rust at a sentinel soybean site in Martin county. This is the first report on soybeans planted in 2006. Martin county is located in southeastern Florida near West Palm Beach . Even with this find, Florida officials feel the overall spore production in the state is still low.

Florida Partnership Enables Field Research on Soybean Rust

April 11, 2006

Last month, the North Central Soybean Research Program (NCSRP) board voted to fund an innovative partnership between NCSRP scientists and the University of Florida in Gainesville. University of Florida researchers are opening the doors of their Quincy Research Station, providing Midwestern scientists with lab space, greenhouse space and land for Asian soybean rust research trials.

"In Florida, scientists have unlimited, year-round access to Asian rust," explains Gregg Fujan, NCSRP president. "They don't have to operate in a containment facility or controlled environment. So NCSRP-funded scientists can do practical, in-field research without spending a fortune"... read more in the April issue of the PHI e-newsletter»

For Midwestern researchers, access to Asian soybean rust is critical. This was an opportunity we simply couldn't pass up because if successful, the benefits to Midwest soybean producers are too great. Many thanks to leaders from the Iowa, Kansas and Wisconsin checkoff boards, who've agreed to partner with NCSRP to help cover the cost of this initiative. We hope other checkoff boards also will see the value in this initiative and partner with us." - David Wright, director of the North Central Soybean Research Program's Plant Health Initiative.

Include the Bean Leaf Beetle in Early-Season Scouting Schedule

May 30, 2006

Extension entomologists in the North Central region recommend including the bean leaf beetle in early-season scouting schedules this year. As soybeans emerge, beetles move from cultivated and wild legumes to soybeans, where they continue to feed and lay eggs in the soil. Fields planted earliest in an area are most at risk of establishing high populations of the beetle.

Signs of feeding are easily recognized by small round or oval holes in the leaf edges and in the middle of cotyledons and young leaves. Occasionally the beetles may consume the entire young leaf. Fortunately, plants generally recover from the injury at this stage as long as the growing point is not killed.

Because the bean leaf beetle is known to transmit Bean Pod Mottle virus, researchers at Iowa State University have constructed a flowchart to help growers with early-season management decisions. The flowchart is a dynamic, two-pronged decision guide based on field history. It presents two management plans: and one for managing both the beetle and Bean Pod Mottle virus, and one for managing only the beetle.
View flowchart (pdf)»
Read more about bean leaf beetles»

Japan Setting New Residue Limits

March 10, 2006

If Asian rust hits in 2006, growers will need to consider Japan's new residue limits in their management plans. To be released in May by the Japanese Ministry of Health, the limits cover all imported food and grain, including pesticides used on both food grade and commodity soybeans. Growers will need to make sure they don't make an application too late on soybeans, because it may result in Japan rejecting the entire shipload. Too many rejected loads, and the United States may fall out of favor as a source of soybean for Japan, our third largest customer for soybean export.

"We're dealing with new invasive species, Asian rust and aphids, and we also have to be mindful of applying late-season chemicals that might result in residue limits that exceed limits mandated by our Japanese customers. It's going to be a balancing act, as growers try to improve late-season plant health while observing pre-harvest intervals." -- David Wright, PHI director.

Asian Soybean Rust is the Focus of ICM Newsletter

March, 2006

The February 27 issue of the Integrated Crop Management newsletter from Iowa State University contains 11 articles on soybean rust, including a review of 2005, the effects of rust fungicides on other soybean diseases, a review of the rust monitoring efforts, and factors that will affect the 2006 season...read the ICM newsletter»

Asian Soybean Rust Overwinters in Several Southern States

March 2, 2006

Scouting for soybean rust (SBR) continues on kudzu patches across the south from Florida to Texas. According to the USDA Soybean Rust Information Site, reports of overwintered SBR on green kudzu in 2006 have been confirmed in one county in Texas, 5 in Alabama, 11 counties in Florida and 4 counties in Georgia. Scouting personnel have been destroying infected kudzu after rust identification.

These reports suggest that the rust fungus has survived the winter over a much greater area in North America than it did last winter. But it's too early at this time to tell whether the increased amount of inoculum will affect soybeans in the North Central region this season or not. The risk of a rust epidemic will be depend on the amount of rust that develops on the new soybean crop in the south, and will be greatest if environmental conditions in the spring and summer months favor rust development and spread. The USDA Soybean Rust Information Site (www.sbrusa.net) provides an excellent means for growers and advisors to monitor the progress of rust in areas to the south as the season progresses.

Good News from South America

March 10, 2006

Iowa State University Extension economist Robert Wisner just returned from Brazil, and reports that breeders at the Mato Grosso Foundation believe they'll have a soybean variety that's Asian rust-resistant within two to three years. Officials at EMBRAPA (Brazil's USDA), however, suspect it might take a bit longer. Wisner also reports that the 2006 Brazilian crop is projected to be 58.5 million metric tons, larger than last year's by an estimated 5.5 million bushels. Source: Corn and Soybean Digest E-News.

Producers in the S.M.A.R.T Program Report Increased Yields

January 4, 2006

Agronomists at Mississippi State University began the S.M.A.R.T program (Soybean Management by Application of Research and Technology) in 1992 to demonstrate the impact that intensive management can have on soybean yields. The producers who have participated in the program so far have not been disappointed. The key to their success is managing soybeans on a field-specific basis, and managing from the ground up. They look for soil problems first: drainage, soybean cyst nematode, soil fertility, poor seedling growth. Poor root health is often the most yield-limiting factor in soybeans. And when you identify and eliminate the most limiting factor, you harvest yield…read more about the S.M.A.R.T program (Part I) and improving soybean root health (Part II and Part III).

Educational Tools on Soybean Growth and Development Available

February 20, 2006

Soybean Growth and Development (PM 1943), a 28-page publication published by Iowa State University Extension, explains soybean growth and development through the life cycle of a maturity group II soybean variety. Print copies are available for $4.00 from the ISU Extension Distribution Center website or by calling 515-294-5247. An online overview of soybean growth stages, as well as a slideshow of soybean growth and development, are available at the ISU Soybean Management website»

APS January Feature Article About Soybean Rust Just Published

January 10, 2006

The January feature article on the American Phytopathological Society website, APSnet, describes in detail the development of Asian Soybean Rust in the southeastern U.S. in 2005, with a particular focus on the Georgia monitoring and fungicide evaluation programs ...read the APS feature article»

Proceedings of the National Soybean Rust Symposium are Available Online

December 20, 2005

350 university, government, and industry soybean workers met recently at the National Soybean Rust Symposium in Nashville, TN. The event was organized by the Americal Phytopathological Society to provide soybean workers the opportunity to share the information on soybean rust that was acquired during the 2005 crop season, and to make plans for next season. The entire proceedings from this symposium are available online at the Plant Management Network website... view symposium proceedings»

Radio Interview with Dr. David Wright on Emerging Soybean Virus Diseases

November 18, 2005

Soybean producers have dodged the Asian soybean rust bullet this growing season - but the Plant Health Initiative is reminding producers that rust isn't the only disease of concern. In fact , more than 40 University researchers, and state and federal government representatives recently met to review research on emerging soybean virus diseases, and what is needed to address them...listen to radio interview with Dr. Wright»

NCSRP-Funded Research Currently Most Highly-Cited Research Paper in Plant and Animal Sciences

October 30, 2005

A research paper published by university scientists Steve Clough and Andrew Bent, and funded by the North Central Soybean Research Program, is currently ranked at #1 among Plant & Animal Science papers published between January 1995 and June 2005. It was also selected as the Plant & Animal Science "Current Classic" for September 2005 by the ISI Essential Science Indicators, an organization that tracks science trends and performance.

Clough and Bent, plant geneticists at the University of Illinois UC and the University of Wisconsin, work on aspects of biotech plant breeding with a method called plant transformation. Round-Up-resistant soybean and insect-resistant Bt corn are two successful products of this method, which, according to Dr. Bent, are just the tiny tip of the iceberg. Underlying that are thousands of experiments where plant transformations are used to learn how plants work, how they respond to stress and disease, and how grain composition is determined.

The particular benefit of this NCSRP-funded research is that it has made the transformation of at least one plant species, Arabidopsis thaliana, exceedingly easy, inexpensive, and accessible to researchers. Traditionally, plant transformation is quite labor-intensive, expensive, and requires specialist practitioners. It’s a bottleneck that slows down progress. With funding from NCSRP, Clough and Bent were able to refine the method, uncover mechanistic details about how the transformation works, and publish this widely-cited paper. The impact of this Arabidopsis transformation method has been huge.

Although Arabidopsis thaliana isn't a crop plant, it is an important genetic model to work with due to its small size, rapid generation time, and small genome. What people learn about Arabidopsis is often applied to soybean research. In fact, many of the leading ideas for crop biotechnology are coming from research using Arabidopsis as a model.

Dr. Bent has tried to get a similarly simple transformation method working for soybean and other plant species as part of his NCSRP-funded grant. Although they were not yet able transform soybean by this method, the researchers have recognized that the development of the floral dip transformation has been a significant step in the understanding of where and why plant transformations work, and thus a significant step in surmounting the remaining barriers to transformation of other plant species in t

North Central Soybean Researchers Discuss the Potential Impact of Emerging Soybean Virus Diseases

October 25, 2005

NCSRP hosted a meeting of the region’s top entomologists, plant breeders, and plant pathologists on Monday to discuss the potential impact of emerging virus diseases on the productivity of soybean in the region. Because virus diseases are spread by insect vectors, the introduction of the soybean aphid and the high populations of the bean leaf beetle in some years is reason for both scientists and growers to be prepared for the possibility of a more widespread occurrence of virus diseases in North Central states.

John Hill, a leading virologist at Iowa State University, chaired the one-day symposium which concentrated on what we do know, and what we still need to know, about diseases such as soybean mosaic virus, bean pod mottle virus, alfalfa mosaic virus, and soybean dwarf virus, and the insect vectors that spread them.

Researchers agree that management of virus diseases requires a combination of strategies depending on the virus or viruses involved, and may include soybean variety selection, planting virus-free seed, controlling insect vectors, and managing crops to avoid periods of peak insect activity.

Farmer Leaders Pleased With the Effectiveness of the Sentinel Plot System

September 6, 2005

Farmer leaders have been very pleased with the effectiveness of sentinel plots in helping experts identify areas that were affected by soybean rust. The sentinel plots, funded by soybean checkoff dollars, were recognized by Gregg Fujan, Chair of the NCSRP Board of Directors, as " the leading indicator in the advancement of rust from the rust overwintering areas to the soybean belt". In this growing season, rust was found on either kudzu or sentinel plots weeks before any commercial field in the area.

Efforts are being made to insure that the sentinel plot system is repeated for next year. The USDA will undoubtably continue efforts to provide soybean producers with an adequate safety net, including funding sentinel plots, monitoring (www.sbrusa.net), as well as intense scouting by University and government experts. Although other monitoring efforts will be scrutinized, such as air spore traps, efforts for a broad-based monitoring system will continue.

End of Season for Soybean Rust 2005

September 6, 2005

Rust didn't become an issue in the upper midwest this year. Why? The overwhelming reason was that there was not an abundance of inoculum. The freeze over the winter months nearly eradicated rust from the U.S., and the environmental conditions, in both the southeast and midwest, were not conducive to the build-up of inoculum. This puts us right where we were on December 1 last year: we know rust is in several locations in the country, and only Mother Nature will determine the severity of soybean rust in soybean production states in 2006.

Did experts overreact in 2005? "No", according to David Wright, Coordinator of NCSRP, "the experts did not overreact. States were prepared to handle an epidemic of soybean rust in 2005, which is no small feat. Tremendous effort was put into training crop advisors, soybean producers, and agricultural agencies in the recognition and potential impact of this disease. The fact that soybean rust was not a significant issue simply gives the soybean industry another year to prepare for the inevitable. It is better to be overprepared but ready, than to be complacent and get caught off guard"

Late Season Disease Scouting Helps in Next Year's Planning

August 26, 2005

September is the time to scout for brown stem rot (BSR) and other late-summer diseases. BSR, sudden death syndrome (SDS), and white mold are common and potentially yield-threatening soil-borne diseases that show up this time of year in the north central region. If you find these diseases in any fields, the information you gather this season will be useful to manage the disease in your next soybean crops. If you are unaware of their presence, they will continue to build up in the soil.

Foliar symptoms of late-season diseases look similar, and may also be confused with early maturity or drought. Check for BSR by splitting stems longitudinally and checking for internal stem symptoms. Healthy stems have white tissue in the center; infected tissue is brown. Browning of the tissue progresses upward in the stem during the growing season, so always check the lower stem first...read more»

Still Time to Check for SCN on Soybean Roots

August 17, 2005

Mid-July until 3 to 4 weeks before harvest is a good time to inspect roots for soybean cyst nematode females. Checking for SCN on roots is even more accurate than a soil test to determine if SCN is present in a field.

At this point in the season, adult SCN females and cysts appear on new roots that are located deeper down in the soil as well as farther laterally from the stem of the plant. Dig, rather than pull, the plants for best results. Adult females and cysts will be a lot smaller than the nitrogen-fixing nodules, about the size of a pinhead. Read more about SCN sampling»

Scouting for Rust Continues in the South

July 25, 2005

Intensive scouting for soybean rust continues in the southeastern U.S., where environmental conditions have been ideal for the reproduction of the rust fungus. State and extension personnel have identified a few new infections in sentinel plots.

Growers in the North Central region should not be applying preventative fungicides for rust at this time. Section 18 fungicides can only be applied when rust is imminent.

Soybean Rust Forecast

July 19, 2005

Due to the limited rust activities in the south, there is a low chance that serious epidemics may develop at this stage. For most of the North Central region, considering the present scenario, it is unlikely we will find soybean rust in our fields before mid-August. If rust is found around mid-August, the disease is unlikely to cause any significant damage....read more»
Soybean rust forecasts will be posted here throughout the 2005 season

Soybean Rust Confirmed in Alabama and Florida Sentinel Plots

July 5, 2005

University and government researchers recently confirmed that Asian soybean rust has been found on soybeans in two sentinel research plots in Alabama and Florida. The sentinel plot finds are significant, because they demonstrate that rust is starting to move beyond Florida. Growers need to understand, however, that it’s still a very small source of inoculum and does not mean imminent disease...read more»

Don't Overreact to Unconfirmed Rust Reports

June 24, 2005

Spores similar to those produced by the Asian soybean rust fungus have been found in a spore trap set up by the LSU AgCenter in a soybean field near St. Joseph, LA. However, only three spores were in the trap —- too few for confirmation. Spore traps have been set up throughout the soybean growing areas of the U.S. as part of the national monitoring effort for this disease. These traps will pick up all spores that are spread by wind, many of which will look similar to Asian soybean rust. It will be important this season to keep informed of these finds, but to not overreact to them until confirmation has taken place.

NCSRP Funds Research on Fungicides and Soybean Rust

May 10, 2005

One of two significant projects on Asian Soybean Rust, the goal of this project is to develop recommendations for the use of fungicides in the mangement of soybean rust. Participating reseachers are focusing on three aspects:

• Application methods, nozzle types, and pressures needed to maximize canopy coverage,
• the effects of tank-mixing insecticides and fungicides on insect populations, fungi control, and soybean yields; and
• the efficacy of specific fungicides.

Researchers from the USDA/ARS/University of Illinois, University of Nebraska, University of Kentucky, Mississippi State University, South Dakota State University, and Louisiana State University are working collaboratively on the project.

Brochure on Soybean Rust and Crop Insurance Available from the USDA Risk Management Agency

April 21, 2005

The two- page brochure, Soybean Rust, Crop Insurance, and You, outlines how insured farmers must seek out and follow the good farming recommendations of agricultural experts such as extension agents and certified crop consultants, and document the advice received and actions taken. It recommends that farmers follow developments as to the identification and spread of Asian soybean rust, as well as treatments that may apply to their situation. View publication (pdf) »

New Reference Book on Using Foliar Fungicides to Manage Soybean Rust

April 11, 2005

A full-color 50-page publication called Using Foliar Fungicides to Manage Soybean Rust is now available in print form or in pdf format on the web. The publication was prepared by soybean pathologists working in many regions of the U.S. It covers the factors involved in making fungicide spray decisions, choosing fungicides, and strategies for fungicide application, with numerous illustrations, tables, and charts.
View publication»
Call NCSRP for free print copy: 1-800-383-1423

Asian Soybean Rust Found on Volunteer Soybean in Georgia

April 28, 2005

Asian soybean rust was found on “volunteer” soybeans (i.e. soybeans sprouting from seeds left in the field from the 2004 crop) by the University of Georgia Cooperative Extension Service...read more»
View USDA Soybean Rust map»

Soybean Rust Identified in a Third County in Florida

April 11, 2005

Soybean rust has been found in a third Florida county this week on kudzu. The latest find is in Marion county, to the north and east of the Florida counties in which rust has been identified in 2005. View USDA map of the finds to date»

New Case of Soybean Rust Confirmed in Florida

March 22, 2005

Florida state agriculture officials confirmed a positive find of Asian soybean rust on kudzu and the first involving new kudzu growth in 2005. The new case was found in Hernando County in west-central Florida. Hernando county is one county north of Pasco County, where rust was first found this year. The finds were confirmed by microscopy at the Florida Division of Plant Industry, and traditional PCR at the University of Florida. Germination tests confirmed spore viability.

USDA Soybean Rust Mapping Website is Active

March 20, 2005

The USDA Soybean Rust Mapping website displays scouting and disease observation locations, and rust forecasts, based on soybean rust monitoring networks, forecasting models, and input from state specialists. Visit the site»
Read more on rust surveillance and forecasting»

NCSRP Publication on Soybean Rust

February 18, 2005

Order a free copy of the NCSRP Asian Soybean Rust Research Update or read online.

Soybean Checkoff Leading the Battle Against Soybean Rust

February 18, 2005

NCSRP and the United Soybean Board sponsored a national Strategic Planning Session with over 100 soybean research scientists. Now that rust is in the United States, a widespread and focused research program can begin....read more» (pdf)


PHI e-Newsletters

PHI e-newsletter - December 2006
PHI e-newsletter - June 2006
PHI e-newsletter - April 2006
PHI e-newsletter - March 2006

Information on these pages is from the cooperative effort of researchers throughout the North Central states. Information from this site can be copied and distributed for educational use. Please credit the source with our name and URL: NCSRP Plant Health Initiative at www.planthealth.info. Please do not use copyrighted photos without permission.