Kentucky: Soybean Sudden Death Syndrome Showing Up

Soybean sudden death syndrome (SDS) caused by the root-rotting, soil-borne fungus Fusarium virguliforme, is beginning to show up in soybean fields across Kenturcky. To my knowledge, all of the sightings are in patches of plants or individual plants, and are not field-wide. SDS has been seen in Kentucky each year, to one degree or another, since 1985.

SDS is evident first in foliage where plants show yellow blotches between the veins.

Sometimes this this early symptom can look almost virus like. In most cases, blotches eventually coalesce and result in a yellow and brown discoloration between the veins, but the veins remain green. In severe cases, the leaflets will fall off, but the petioles will remain attached to the plant. Foliar symptoms are the result of a toxin produced by the fungus in diseased root tissue.

The foliar symptoms descibed above can look similar to stem canker, Dectes Stem Bore injury, and even pytotoxicity symptoms caused certain triazole fungicides, so foliar symptoms in and of themselves are not diagnostic for SDS. Additional symtoms include severely rotted roots (F. virguliforme is a root rot organism) and a light brown discoloration of the stem when sliced open with a knife. Healthy stems will appear a cream color. When all three symptoms are evident, you can be quite confident that you have made a field diagnosis of SDS.

This disease is poorly named in that the disease does not usually suddenly appear, nor is the end result always death. In fact, SDS foliar symptoms first appear much like other diseases, a little at a time. It is only “sudden” if you have not been looking. I have seen plants with SDS recover (put out leaves without characteristic foliar symptoms) and in most cases, the disease comes in too late, or does not impact enough of a field, to significantly reduce yields.

Severe foliar symptoms can be misleading and often do not indicate that the disease has or will significantly impact yields. In fact, I have seen many instances over the last 27 years where severe foliar symptoms developed across a field (late), but the yield retieved was a record for the field. So with SDS, when symptoms show up relative to crop stage is everything.

Fusarium virguliforme infects roots early in the season and foliar symptoms normally appear in the reproductive stages, as is the case in fields this year. Abundant soil mositure encourages SDS and that is why we are seeing more of the disease this year than we normally do. In a more typical year, a greater extent of SDS is often associated with very early planting; doublecrop beans are rarely affected. However, in a year like this one, planting date associations are blurred and we may find that the disease even ends up developing in doublecrop soybeans.

The best way to control SDS is to plant a resistant variety. They are not that hard to come by. But there is nothing you can do to slow or stop SDS once it is evident in a field. For sure, applying a fungicide WILL NOT HELP.

In summary, SDS often has a “bark” more hurtful than its “bite”. Twenty-seven years of experience in Kentucky has shown that people often get all worked up over SDS because of the hyped-up name for the disease and because symptoms usually show up late in the season in an otherwise good looking crop. However, the end result is commonly little or no measureable yield loss, unless the disease is widespread and severe in a field before pod fill is complete, which is rare in Kentucky.

Leave a Reply

Fungicides Stories
FungicidesSudden Death Syndrome, Brown Stem Rot Reported In Indiana Soybeans
September 3, 2014
Farmers and retailers should be watching for symptoms of these two diseases over the next few weeks as they are best managed through preventative methods. Read More
FungicidesResearchers Target Soybean Disease With Genetic Resistance Study
August 6, 2014
University of Illinois researchers will share new information on controlling sudden death syndrome through genetic resistance at this year's Agronomy Day. Read More
Soybean field
FungicidesValent Launches New Seed Protection Fungicide For Soybeans
July 16, 2014
The INTEGO SUITE System contains the first new, novel seed protection fungicide chemistry registered in 30 years by the EPA for protection against Pythium and Phytophthora. Read More
FungicidesNew Players May Make Pest Headlines In Corn, Soybean
April 1, 2014
The usual insects and diseases took a bit of a break in 2013, but other culprits surfaced — and could return. Read More
Top 100 Articles
CropLife 100Pinnacle Agriculture Acquires Minnesota Retailer
April 14, 2015
Pinnacle Agriculture Holdings, LLC, ranked No. 6 on the CropLife 100,  has successfully acquired Liebl Ag, LLC in Ada, MN.  Read More
CropLife 100CHS, Aurora Cooperative Complete Fertilizer Storage, Grain Shuttle Loading Facility
April 13, 2015
CHS Inc., the nation’s leading cooperative and ranked No. 5 on the CropLife 100, and Aurora Cooperative (ranked No. 21) Read More
CropLife 100GROWMARK Acquires Missouri Refined Fuels Terminal
April 2, 2015
Bloomington, IL-based GROWMARK and Magellan Pipeline Co. have entered into an agreement in which GROWMARK will acquire the refined fuels Read More
CropLife 100Wilbur-Ellis Acquires South Dakota Retailer
April 2, 2015
Wilbur-Ellis Co.’s Agribusiness Division, a recognized leader in precision agriculture technology and the distribution and marketing of plant protection, seed Read More
CropLife 100The McGregor Co. Closes Smith-Kem Acquisition
April 2, 2015
The McGregor Co. — ranked No. 16 on the CropLife 100 list of largest U.S. ag retailers — has completed Read More
CropLife 100BRANDT Commemorates National Ag Day
March 20, 2015
The Illinois agriculture community gathered at BRANDT global headquarters on March 18 to celebrate National Ag Day behind this year's theme Sustaining Future Generations. Read More
Latest News
Industry NewsCHS Insurance Names New Director Of Sales
April 17, 2015
Bryan Lewis has been named director of sales for CHS Insurance, the nation’s largest agribusiness insurance broker and full-service insurance Read More
Mature Waterhemp in Corn
HerbicidesGenetic Literacy Project: There’s No Such Thing A…
April 17, 2015
Read the latest “analysis” on GMOs from Consumer Reports and you’ll “learn” that glyphosate, the chemical developed by Monsanto (its Read More
HerbicidesNew Resistance To 2,4-D Discovered In Australia
April 17, 2015
In a world-first case of herbicide resistance, researchers have confirmed that sowthistle weed in the south east of South Australia Read More
ManagementNews From RTP Company Visits and Growers Buying Older S…
April 16, 2015
Paul Schrimpf and Eric Sfiligoj discuss recent trips to the Research Triangle Park area and market seed sales trends. Read More
soybean field
StewardshipNew ASABE Standard Establishes Framework For Sustainabl…
April 16, 2015
The American Society of Agricultural and Biological Engineers (ASABE) has initiated a project to develop a new standard to establish Read More
MicronutrientsSouthern States: An Inside Look At Our Tissue Sampling …
April 15, 2015
Remember learning about the food pyramid in school? The nutritional diagram recommends the proper amount of nutrients you need on Read More
Industry NewsArysta Adds New U.S. Fungicides Marketing Manager
April 15, 2015
Arysta LifeScience North America recently hired Deneen Sebastian as its Marketing Manager for U.S. Row Crops, Fungicides. Most recently, Sebastian Read More
FungicidesVerdesian Launches Phosphite-Based Cereal Fungicide
April 14, 2015
A new, phosphite-based fungicide designed for improved suppression of deoxynivalenol (DON) in wheat and barley infected by Fusarium head blight Read More
Mature Waterhemp in Corn
HerbicidesSURVEY: Close To 90% Of Growers Battle Weed Resistance
April 14, 2015
Herbicide resistance management continues to be a priority for corn and soybean growers, and they’re working together more effectively to Read More
CropLife 100Pinnacle Agriculture Acquires Minnesota Retailer
April 14, 2015
Pinnacle Agriculture Holdings, LLC, ranked No. 6 on the CropLife 100,  has successfully acquired Liebl Ag, LLC in Ada, MN.  Read More
StewardshipFMC Corp. Joins Sustainable Agriculture Alliance
April 14, 2015
FMC Corp. has joined Field to Market: The Alliance for Sustainable Agriculture, a multi-stakeholder initiative working to define, measure and Read More
Industry NewsArysta Adds Two To Goëmar Sales Team
April 14, 2015
Arysta LifeScience North America recently announced two new additions to the Goëmar sales team: Steve Kelly, Technical Service Manager – Read More
Valley Variable Rate Irrigation
Precision AgVariable Rate Irrigation Gains Followers
April 14, 2015
Irrigation systems have had the ability to apply different amounts of water throughout a field for decades, using timers that Read More
CropLife 100CHS, Aurora Cooperative Complete Fertilizer Storage, Gr…
April 13, 2015
CHS Inc., the nation’s leading cooperative and ranked No. 5 on the CropLife 100, and Aurora Cooperative (ranked No. 21) Read More
Soybean field
Industry NewsThree Ag Co-ops Poised For Possible Merger
April 13, 2015
Following months of study and preparations, the Board of Directors for United Farmers Coop (UFC), Farmers Elevator Cooperative (FEC) and Read More
Eric SfiligojAgriculture Braces For More Belt-Tightening
April 13, 2015
Spring is in full bloom across the U.S. and ag retailers and their grower-customers are busily getting into high gear. Read More
ManagementPollinator Health and Washington, DC
April 9, 2015
CropLife America’s Kellie Bray speaks with CropLife Editor Eric Sfiligoj regarding bee health and proposed Beltway regulations. Read More
InsecticidesValent Takes On MGK Insecticide Portfolio
April 9, 2015
As of April 1, Valent U.S.A. Corp. became the exclusive provider of the MGK crop protection line of insect control Read More