Soybean yield is often limited by soilborne pathogens. The average United States soybean yield is 43.9 bushels per acre or only about 27 percent of known yield potential (160 bushels per acre). The difference between harvested yield and potential yield is lost to a plethora of environmental stresses such as heat and drought as well as a complex of poorly understood soilborne pathogens.  These pathogens invade plant roots causing tissue decay, a reduction in the number of root tips, a decrease in nodule size and loss of root function.

Major yield losses are found in areas where soils have high clay content or remain saturated for long periods of time. The key to improving soybean yield is to improve root health.

One aspect of improving root health is increasing the number of roots. Water and nutrients are absorbed into the root just behind the root tip, so increasing the number of roots means more water and nutrients can be absorbed.  Healthy roots trigger faster plant growth and seed development when environmental conditions are not growth limiting.

In addition to anchoring the plant, the soybean root is responsible for absorbing large amounts of water and nutrients and then transporting them to the stem and leaves. When roots are damaged the plant’s ability to obtain water and nutrients is greatly reduced. Preventing  damage to the root removes the stress and helps avoid unnecessary yield loss.

The most important pathogens associated with seedling root health include the soybean cyst nematode, Pythium species, Phytophthora sojae, Rhizoctonia solani, and Fusarium species. Iowa State University researchers found that each of these pathogens has been found to impair root health alone and in combination with each other.

Pythium species cause seed decay, pre-emergence damping off and early post-emergence seedling death. Seed infected with Pythium species may decay before germination and as they do, become soft and rotted. Phytophthora sojae also causes a soft, wet rot of seed or seedling tissue similar to that of Pythium species. Infected seedlings may die prior to emerging from the soil or shortly thereafter.

Symptoms of Rhizoctonia solani infection generally show up on seedlings as dry, dark reddish-brown lesions just above the soil line. Seedling loss from Rhizoctonia seedling blight is less common that from Pythium seed decay and Phytophthora root rot but when present, stand loss can be severe.

The traditional soybean-corn production system creates a monoculture that creates an environment that promotes the build-up of root-infecting pathogens.

Researchers at Iowa State University report that within the soybean- corn rotation, there may have an inadvertent increase of populations of root-infecting pathogens, thereby increasing root damage. For example, there are reports from Ohio State University that isolates of Pythium species and Rhizoctonia solani are becoming resistant to commonly used fungicide seed treatments. They suggest that if these isolates are pathogenic to both soybean and corn, it is likely the pathogen inoculum is also increasing in the field. Thus, an increased knowledge of the role of Pythium species and Rhizoctonia solani in the soybean-corn rotation is necessary for improving yield.

Improving root health

The first 10 to 14 days following soybean planting is the window of opportunity for Pythium and other soilborne fungi to infect the plant. Implement practices that promote quick germination and seedling emergence to prevent infection.

• Plant high quality seed and plant into a good seedbed
• Plant seed that has resistance to Phytophthora sojae. Specific resistance is controlled by major resistance genes such as Rps1k. In addition, select varieties with high partial resistance (tolerance) when possible.
• Plant where drainage is adequate, or improve drainage if possible. Avoid low areas of fields, especially if a field has a history of seedling or root rot problems.
• Consider that germination will be quickest when soil temperatures are greater than 65°F

What to do if seedling diseases are present

• If dead plants are scattered throughout the field, and no significant stand reduction is apparent, then no action is needed if the disease is Pythium or Rhizoctonia damping off.
• If seedling loss is severe, consult a certified crop advisor to determine if replanting is necessary. Replanting is not always necessary.
• Take good disease notes and use preventive measures such as seed treatment or resistant varieties to reduce the likelihood of a disease problem in the next soybean crop.

If replanting is necessary

If poor stands are due to diseases, fungicide seed treatments can be used in replanting to avoid further damping off, especially for Rhizoctonia and Phytophthora. If poor stands are due to a low germination rate, a seed treatment cannot improve seed germination rate or seed vigor.

No-till farming is a growing practice in many areas of the United States. An estimated 50 percent of the acres planted to soybeans in 2009 were done so without tillage according to a recent USDA Economic Research Service report. Farmers are adapting no-till soybean production at a faster rate than they are for corn, cotton and rice.

There are many motives for adapting no-till. Some see it as a “greener” way to produce a global food supply while conserving soil and water resources so generations to come will be able to enjoy the benefits we do. Others see it as building resiliency into a production system faced with challenges of floods, drought, diseases and pests influenced in part by changes in climate. No matter what the reason, no-till practitioners are emphatic in their belief that it contributes to the sustainability of soybean production.

Long time practitioners of no-till admit there is no one way of doing it. Soils respond differently to no-till, so no single piece of equipment or common practice guarantees success. Successful no-tillers admit, however, they’ve learned from their mistakes and from listening to others.

Jim Specht, University of Nebraska, professor of agronomy offers these words of advice for getting the most out of no-till soybean production systems.

Plant early- Iowa State University reports delayed planting of high yielding fields results in a yield loss of 0.3 to 0.7 bushels per acre per day with the largest yield reductions occurring after May 10.  In Nebraska, the yield penalty for delayed planting is between 0.3 and 0.6 bushels per acre per day of planting delay after May 1.

Choose soybean varieties wisely- Variety selection for field-specific problems such as diseases and SCN is important for success in no-till.  Loren Giesler, University of Nebraska Extension plant pathologist agrees and says, “Farmers who know they have SCN can gain, on average, five to six bushels per acre simply by planting a SCN-resistant soybean variety, according to yield trials.”

Use a fungicide seed treatment- There is no doubt that seed-applied fungicides improve stand establishment in cool soils common in no-till fields. This is especially important to famers who are planting fewer seeds per acre to reduce input costs without sacrificing yield. To them, every plant counts. To others, it’s insurance. University studies show that soybeans are very resilient and will compensate for a few missing plants.

The benefit of using an insecticide seed treatment is unclear. Some university research shows that an insecticide seed treatment alone doesn’t always improve yield. The research also shows yield increases are inconsistent when an insecticide/fungicide seed treatment is used. Although the industry doesn’t have a complete understanding of how to use this technology, the observed benefits can’t be ignored.

Consider strip tilling soybeans in heavy residue situations. For those soybean producers whose prior crop corn yields were high, there will be a lot of corn residue left behind.  Specht says, “For every pound of grain removed there is a pound of residue left behind so, a 250 bushel per acre corn crop leaves behind 14,336 pounds of residue per acre.” He suggests producers will get better planter soil closure over the soybean seed if a strip of corn residue has been cleared.  The soil in that strip also warms up faster, which benefits early planted soybeans.

Every year more farmers are seeing the wisdom and rewards — both economic and personal — in no-till soybean production systems. Because each farm is different, there’s no single formula for sustainable success in no-till, but these principles are a good place to begin.

This year, many Midwest farmers discovered first-hand the effect of root infection by the fungal pathogen that causes sudden death syndrome (SDS): yield losses of 40 percent were recorded in some fields. But it’s not just SDS that is limiting yield in soybean fields. Wounds caused by soybean cyst nematodes (SCN) and by maturing females serve as entry points for other soilborne pathogens. Brown stem rot (BSR) also infects roots of young seedlings and is often found in the presence of SCN.

Each disease can cause significant yield loss, up to 50 percent under optimal conditions. Even worse is the interaction between SCN and the fungal pathogens that cause SDS and BSR which can cause even more yield loss.

First discovered in 1971 in Arkansas, SDS has quickly spread throughout the Soybean Belt and is now found in areas of South Dakota and in 23 counties in Minnesota. It is likely spreading north with the movement of SCN; the SDS fungus is commonly found in the cysts. Because of this close association with between SDS and SCN, assume that if you have one or the other, you probably have both.

BSR has been found in nearly all Midwest soybean producing states. The increase in the incidence of BSR is thought to be a result of a monoculture created by the traditional soybean corn rotation which encourages a build-up of the BSR pathogen in the soil. Like SDS, the fungus that results in BSR infects the root early in the growing season and is favored by cool, wet soils.

Minimizing yield loss from SDS and BSR begins with managing SCN in fields where combinations of these stressors co-exist. SCN cannot be eliminated once it becomes established in a field, but its influence on other soilborne pathogens can be reduced with proper management.

A new publication is now available to help soybean producers manage SCN. The SCN Management Guide, fifth edition provides soybean producers with science-based information generated from many years of checkoff funded research that is proven to reduce SCN populations.

With currently available management options, it is much easier to keep low numbers low than it is to try and drive high SCN numbers down. By managing SCN you can:

• Improve soybean root and plant health and yield;
• Keep SCN numbers low; and
• Preserve the yield potential of resistant varieties

Because no single management practice will meet all three goals, you must use an integrated approach that combines several components. Chief among these are the use of varieties resistant to SCN and with good field tolerance to SDS and BSR, rotation with non-host crops when possible, maintaining a well-drained seedbed, use of fungicide and insecticide seed treatments to promote early seedling health.

Click on the Free Publications link above to receive your free print copy of the SCN Management Guide, or view online – see sidebar to the right.

Farmers will need to employ multiple tactics to improve soybean yield. The most important will be employing management tactics that improve soybean root health.

A healthy soybean root is an important component to soybean yield. A soybean plant with a healthy root system is more efficient in taking up water and nutrients, and can better withstand the effects of infection by soilborne pathogens and soybean cyst nematode.

This year, many Midwest farmers discovered first-hand the effect of root infection by the fungal pathogen that causes sudden death syndrome: yield losses of 40 percent were recorded in some fields.

But it’s not just sudden death syndrome that is limiting yield potential in soybean fields. Soybean cyst nematode remains the most serious nematode pest of soybean in the United States.

For many years early soybean planting has contributed to soybean seedling damping off, which reduces stand establishment. Pythium, Rhizoctonia root and stem rot, Phytophthora root rot, and Charcoal rot are root and stem diseases caused by soilborne pathogens and all are known to cause significant yield loss. It is interesting to note that research conducted at Iowa State University discovered that some isolates of Pythium recovered from diseased soybean seedlings were also highly aggressive against corn. This suggests that management tactics to reduce the impact of Pythium species must be utilized in both the soybean and corn crops.

Reducing yield loss from these soybean diseases begins with improving root health. Improving root health begins with refining management tactics. Soilborne pathogens are best managed with a combination of improved soil drainage, fungicide seed treatments, planting high quality seed, crop rotation and tillage practices that minimize soil compaction zones. These management tactics reduce inoculum in the field and limit the amount of water available for the pathogens to germinate and infect.

The importance of a well drained soil became apparent this year as farmers noticed signs of SDS first in low lying field areas and along edges of water ways. Improving drainage in these areas will reduce the severity of SDS and also diseases caused by Pythium and Phytophthora. If drainage in these areas cannot be improved, farmers should consider planting them last.

The importance of managing SCN cannot be overstated. SCN feeding on roots creates openings for opportunistic infection by soilborne pathogens. Researchers recently found greater levels of Pythium species and Phytophthora sojae in roots of SCN susceptible soybean plants. Previous research showed that SDS was more severe in areas also known to be populated by SCN.

Fungicide seed treatments for soybean are an emerging tool that farmers can use to protect yield. Some data suggest that the combination of a fungicide and insecticide seed treatment produces greater yield than using either of the two alone. This suggests that the management tactics to control early season diseases and insects should begin at planting and not after emergence. In other words, Manage Soybeans from the Ground Up to increase soybean yield.

That’s your soybean checkoff. Delivering Results.

Sudden death syndrome (SDS) is ravaging many Midwest soybean fields.

Farmers watched anxiously as low-lying areas of some fields suspiciously turned brown then watched those small areas grow into much larger areas of dying plants. SDS is showing up on a scale not seen since it hit Illinois soybean fields in the early 1990s. This year’s yield losses to SDS are expected to exceed 20 percent in some fields.

The cause of the disease is a soil fungus that is widespread throughout the Midwest. It infects the soybean root early in the plant’s development; later, the pathogen rapidly kills the plant during pod set and pod filling. Infection of the soybean root is worsened by cool, rainy weather throughout the first half of the growing season as well as soil compaction and poor drainage.

Development of SDS depends upon many factors including planting date, tillage, variety of soybean, and the presence of other stresses such as SCN. Early planted soybeans tend to be more heavily damaged than later planted beans because of the more favorable conditions for infection by the soilborne fungus.

The impact of tillage on SDS remains unclear. Reduced tillage, including no-till, may influence the presence of the disease because corn residue causes slower warming and drying of the soil. Corn residue, including dropped corn kernels, harbors the fungus that causes the disease, possibly increasing the amount of the fungus in the soil. However, mature no-till fields tend to drain more quickly than conventionally tilled fields reducing the saturated seed zones that promote infection of the root by the fungus.

Crop rotation is of limited value. University of Illinois researchers report finding SDS in continuously grown soybeans, soybeans following one or two years of corn, and in fields that had been out of soybean production for many years. They reported that the fungus that causes SDS can persist in the soil for many years even without a host crop.

SDS can be more severe in field areas also infested with SCN. Feeding by the nematode on soybean roots adds additional stress that often increases the impact and severity of SDS. Researchers have discovered that cysts can contain the fungal pathogen that causes SDS. However, the two problems are known to exist independently.

Farmers planting maturity group II and I soybeans may be at greater risk of seeing SDS in their fields because soybeans in those maturity groups generally have lower levels of field tolerance to the disease. Although public and private plant breeders are working hard to improve the plant’s performance against the fungus, it will be another 5 to 10 years before greater levels of protection are in place in those maturity groups.

Checkoff-funded researchers throughout the Midwest are working feverishly to solve the SDS problem. Emphasis is being placed on the development of breeding lines with improved tolerance to SDS and screening and categorizing the response of commercial soybean varieties.

Soybean aphid is the most significant above-ground pest that farmers face today. Aphids reduce soybean yield and farmer profitability. They may even transmit viral diseases that can reduce seed quality at harvest. They’re born pregnant so populations can explode almost as quickly as you can turn your head.

Farmers could be facing another year of heavy aphid populations. According to Matt O’Neal, Iowa State University soybean entomologist, he and his Midwest colleagues logged record numbers of aphids headed to overwintering sites in 2009. “The numbers of aphids found on buckthorn last fall were so high that leaves were falling off the plant,” says O’Neal. However, a follow-up visit to those same areas found very few eggs. “This is a bit of a mystery to us,” admits O’Neal. He also admits they’ve seen this before and if history repeats itself, farmers will be spraying for aphids in late July or early August.

“One well-timed foliar application applied after the aphid population exceeds the economic threshold will protect yield and increase profits in most situations,” says O’Neal.

Timing is very important, however.

“Adding insecticide to an early-season glyphosate application as ‘insurance’ doesn’t make sense, says David Ragsdale, University of Minnesota entomologist. Weeds need to be controlled early because they compete for water, nutrients and sunlight. However, aphid populations don’t reach the economic threshold until much later.

The timing of a fungicide application may overlap with the management of soybean aphid. However, many fungicides are toxic to naturally occurring fungi that attack aphids and their use could lead to a subsequent increase in aphid numbers. Farmers who apply fungicide either alone or in a tank mix should monitor those fields for aphid population growth.

Some marketing programs encourage the prophylactic use of fungicides and insecticides as a tactic for managing soybean. Although yield gains using this tactic have been recorded, the results have been inconsistent and thus the benefit this management tactic remains unclear. Ragsdale believes there is a better way.

“Aphid management requires multiple tactics,” states Ragsdale. He advises farmers against becoming too reliant on the “quick fixes” when making management decisions. “Using multiple tactics including cultural, chemical, and biological control is the most effective aphid management plan for long-term, profitable soybean production,” he concludes.

Both Ragsdale and O’Neal recommend regular scouting and a 250-aphid-per-plant threshold for spraying to conserve the natural enemies that prey on aphids. Scout once or twice a week beginning in late June or early July, no later than the R1 (beginning bloom) soybean growth stage, and continue through pod fill. Pay particular attention to late-planted fields, or fields under moisture stress.

Producing high yielding soybeans takes teamwork. The right genetics, a blessing from Mother Nature and the right management decisions by you make a profitable and unbeatable team. Although it’s difficult to predict what curves Mother Nature will throw at you, there are things you can do now to put the odds of bin-busting yields in your favor.

Growing soybeans requires more management today than 30 years ago due to earlier planting and increased disease and insect pressure. Early-season disease infections reduce stands and necessitate replanting and if severe enough can reduce yield. Disease incidence and severity are highest in fields with slow drainage or where periodic saturated soil conditions occur.

Fungicide seed treatments have been shown to reduce stand loss caused by seedling diseases but reports of increased yield have been inconsistent. The effectiveness of fungicide seed treatments is influenced by variety, planting date, soil moisture content, and timing of rainfall. Nevertheless, fungicide seed treatments are a cost-effective management tool to avoid stand loss and potential yield loss from a replanted crop.

The prophylactic use of soil inoculants is increasing. Rising input costs, escalating land prices, and volatile commodity prices are all driving the need for soybean producers to improve profitability. However, the use of inoculants to increase yield may not be the solution farmers are looking for, especially if soybeans have been grown in the recent past. In fact, the prophylactic use of inoculants without an active on-farm testing program could be costing you money. A recent report by several Midwest soybean specialists suggests that prophylactic use of inoculants is not a good management practice for profitable soybean production. However, if a field has not produced soybeans in the past four or five years or has never produced soybeans, an inoculant is needed for nitrogen fixation to occur.

Planting practices, including row width, planting date and seeding rate may have a significant effect on yield. Recent multistate research suggests a final stand of 125,000 plants per acre may be the most economical. While the optimum planting date is state specific the benefit from planting in narrow rows is not. Several research programs have shown that soybeans grown in 15-inch rows can produce higher yields than those grown in 30-inch rows.

Although soybean yields have increased more than 32 percent in the last 30 years those yield gains can quickly be lost to uncontrolled insects such as soybean aphid, spider mite, and bean leaf beetle. Scout individual fields diligently, know and understand economic thresholds, and treat with an insecticide only when necessary.

Control weeds. Weeds left uncontrolled for the first ten days after soybean emergence reduces yield. The use of a pre-emergent herbicide in addition to a glyphosate application controls the early flush of weeds and is a good management practice to delay the buildup of glyphosate-resistant weed populations.

Growing soybeans as a rotational crop is easy. Growing soybeans profitably is more challenging. “Best Management Practices” are available to help you meet that challenge and more; the latest science-based recommendations can be found at planthealth.info. That’s your soybean checkoff. Delivering results.

Although Nebraska farmers produced the nation’s highest soybean yields in 2009 averaging more than 54 bushels per acre, their biggest threat to high yields is coming on fast.

The soybean cyst nematode (SCN) the nation’s number one yield robber is now found in nearly all Nebraska’s major soybean producing counties. In 2009, this tiny yield robbing roundworm was discovered in Phelps, Thayer, and Webster counties.

SCN is one of the most costly and damaging pests for soybean growers. It feeds and reproduces on the roots of soybeans and can significantly reduce yields. “The first indication of a problem is when soybean yields are declining,” says Loren Giesler, University of Nebraska-Lincoln extension plant pathologist.

“Soil testing is very important to improve soybean yields,” he continues. Giesler recommends taking samples from a lot of different areas in the field for testing and then to regularly test fields in subsequent years.

“For long term profitability, Nebraska farmers need to determine if they have SCN because many fields are planted to susceptible varieties,” Giesler continues.

“In most SCN-infested fields in Nebraska, females are evident on roots around July 4,” says Giesler. “However, the absence of cysts on the roots does not mean a field is free of SCN.” In fields with a low population, very few cysts may be found on the roots and they may be easy to miss by visual observation.

According to Iowa State University nematologist Greg Tylka, “Low levels of SCN may not produce visible aboveground symptoms, yet yields may be reduced. High SCN levels typically cause plant stunting and yellowing.”

Giesler agrees and states that, “Aboveground symptoms can be confused with damage from compaction, nutrient deficiencies, drought stress, low-lying wet areas, herbicide injury, and other plant diseases.” Circular to oval areas of stunted, yellowed plants can be observed. Areas of SCN injury are typically elongated in the direction of tillage practices, since the cysts are spread by tillage equipment.

As head of a multi-state SCN education project funded by the North Central Soybean Research Program, Giesler and his colleagues are helping soybean farmers around the Midwest diagnose and manage their SCN problems. This group of experts reached out to 11,000 farmers and crop consultants in 2009 delivering the message that SCN is a problem, but it can be managed.

The Nebraska Soybean Board and the University of Nebraska-Lincoln have partnered to help soybean farmers identify fields that have SCN. “It has been estimated that Nebraska farmers are losing $25 million a year due to SCN,” says Giesler. The Nebraska Soybean Board believes that is $25 million too much. The Nebraska Soybean Board has announced that they will pay for the analysis of soil samples to determine the presence of SCN.

Sample bags and analysis of soil samples for the presence of SCN are available to producers at no cost. For free sample bags, contact your local University of Nebraska-Lincoln County Extension office or Loren Giesler, , at .

That’s your soybean checkoff. Delivering results.

Soybean production practices in the United States have changed tremendously in the last 20 years, often responding to advances in technology and equipment design and availability. As farmers strive to find new information and new technology to improve soybean yield, they may try any number of seed or soil inoculants that are currently marketed. However, the odds of getting a yield increase from inoculants may not be good.

A 2007 survey of farmers by crop specialists at land grant universities found that 18 percent of farmers in Indiana used an inoculant while a separate survey in 2008 found 85 percent of farmers in Wisconsin used one. Inoculating soybeans with products containing the bacterium Bradyrhizobium japonicum is considered an inexpensive management tactic to increase yield. The bacterium forms a symbiotic or beneficial relationship with soybean roots allowing for nitrogen fixation to occur.

Current recommendations for the use of inoculants in the Midwest suggest they should be used if soybeans have not been grown in a field in the last 5 years or if a field has been flooded for more than seven days.

Purdue University researchers concluded in 2005 that “Inoculant use [in a soybean/corn rotation] may be a viable method of increasing soybean yield.” In contrast, researchers from the University of Nebraska-Lincoln recently published that the use of inoculants in a field that had been planted to soybeans in the recent past was unnecessary.

University soybean specialists from several Midwest states recently took a big-picture look at the data from several research trials investigating the performance of inoculants for soybeans. They found that 51 inoculant products had been evaluated in 73 experiments conducted between 2000 and 2008 in Indiana, Iowa, Minnesota, Nebraska, and Wisconsin.

The result?

The research team reported that sixty-three of the 73 environments (environment = year x location) showed no significant yield response to an inoculant. Four of the environments showed a negative response from the inoculants between the range of five and seven percent. And only six of the environments showed a positive response between five and twenty-three percent greater than the control.

Rising input costs, escalating land prices, and volatile commodity prices are all driving the need for soybean producers to improve profitability. However, the use of inoculants to increase yield may not be the solution farmers are looking for, especially if soybeans have been grown in the recent past. In fact, the prophylactic use of inoculants without an active on-farm testing program could be costing you money. However, if a field has not produced soybeans in the past four or five years or has never produced soybeans, an inoculant is needed for nitrogen fixation to occur.

Higher soybean yields can be achieved with greater levels of management and the adoption of current, science-based best management practices. Many of these recommendations can be found on this website. That’s your soybean checkoff. Delivering Results.

The American soybean industry has changed dramatically since soybean rust was found on our shores in late 2004 – and so has our understanding of Phakopsora pachyrhizi, the fungal pathogen that causes the disease.

Five years after soybean rust was discovered in Louisiana, more than 130 scientists at the American Phytopathological Society’s Fourth National Soybean Rust Symposium shared both good and bad news:

• Farms in the United States have not been devastated like those in Brazil, though 2009 saw the first major economic losses to soybean rust in hard-hit fields in Mississippi.

• An array of fungicides were registered and put to good use controlling soybean rust, but reports from Brazil indicate the soybean rust fungus may be getting more tolerant of the triazole class of fungicides in some areas.

• Some populations of kudzu are resistant to soybean rust, but the amount of infected acreage of kudzu that serves as a spore bank has been growing steadily.

• Geneticists are gaining an understanding of how some plants defend themselves against the fungus and are isolating genes breeders can cross into commercial varieties, but they point out that resistant varieties will not be a silver bullet for managing the disease.

Marking a Shift
“This is a celebration of accomplishment,” Anne Dorrance of The Ohio State University told the group in New Orleans, LA. “There has been a tremendous amount of research and sweat and driving hours and laboratory bench hours. We have focused a lot of brainpower on P. pachyrhizi.”

Scientists have published 170 peer-reviewed papers in European and American publications since 2004.The effort to understand and manage soybean rust is by no means over, but the 2009 symposium marked a shift in tone for the group. We’ve gone from the fearing this disease to being confident we can manage it if it becomes a problem.

Among the biggest changes growers will see in the coming year is a scale-down of the Sentinel plot system that has covered the nation’s soybean producing areas since 2005 with meticulously-scouted soybean plots. “With the end of federal grants that have supported the system, funding will drop 60 to 80 percent in 2010 compared to its 2006 to 2008 peak”, says Don Hershman, extension plant pathologist at the University of Kentucky.

Grower Commitment
The Sentinel plot system is a monument to soybean growers’ commitment to staying ahead of soybean rust, Hershman points out. The plots paid off handsomely – both in the value of the data they provided on how soybean rust moves and in the estimated $200 million growers have saved each year by avoiding unnecessary sprays or making properly timed treatments when needed.

Growers shouldn’t worry because if a “perfect storm” of spores and weather sets the stage for Midwestern outbreaks, or the pathogen shifts to a more Midwest-adapted race, they will be protected. “From a Northern perspective, we only need to know where soybean rust is from about April 1,” Hershman says. “The South is where the main event is. If things begin to change, if models indicate there could be a problem in the [Midwest], there will be ad-hoc monitoring. No soybean specialist will drop the ball on this.”