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

Patriot 4440 Sprayer close up
FungicidesNeed For Fungicides High, But So Is Hesitancy To Buy
February 2, 2016
For row crops, 2015 was the perfect year for disease. Awakened by the wet and cool conditions, fungicide demand hit Read More
FungicidesREGALIA Biofungicide Gets New Formulation
January 14, 2016
Marrone Bio Innovations, Inc., a leading provider of bio-based pest management and plant health products for the agriculture, turf and Read More
Golden Harvest Corn healthy leaves
FungicidesArysta Launches New Corn And Soybean Fungicide
November 17, 2015
Arysta LifeScience North America has recently launched ZOLERA FX Fungicide. The highly systemic, powerful fungicide delivers broad-spectrum disease control with Read More
FungicidesFMC Launching New In-Furrow Combo Insecticide/Fungicide
November 9, 2015
FMC is launching Ethos XB insecticide/fungicide, the first of its kind, integrated in-furrow product for insect and disease control. Formulated Read More
Top 100 Articles
Elburn Cooperative
CropLife 100Elburn Cooperative Members Vote To Join CHS
December 28, 2015
With 81% of eligible producers voting, 94% cast an affirmative ballot for Elburn Cooperative, a diversified agricultural retailer based out Read More
West Central Cooperative, Jefferson, IA
CropLife 100Farmers Cooperative-West Central Merger Approved
December 21, 2015
The members of Farmers Cooperative Co. (FC), Ames, IA, and West Central Cooperative, Ralston, IA, have both approved the merger Read More
Wheat Growers Innovation Center, Bath, SD
CropLife 100Wheat Growers Opens Innovation Center
December 21, 2015
Wheat Growers’ commitment in providing its farmer-owners with the latest in technological advancements now has a one-of-a-kind focal point, as Read More
CropLife 100ARA Selects The Andersons As 2015 Retailer Of The Year
December 9, 2015
The Agricultural Retailers Association today named Maumee, OH-based The Andersons as its Retailer of the Year for 2015. The award Read More
CPS Washington Court House John Deere Sprayer
CropLife 100Application Equipment Report: It Is Easy Being Green For Top 100 Ag Retailers
December 5, 2015
On The Muppets television show, Kermit the Frog is famous for singing a song about the troubles he encounters in Read More
Fertilizer Bin
CropLife 100Fertilizer Sales: Another Down Year For Top 100 Ag Retailers
December 4, 2015
In pure number terms, the fertilizer category still dominates all crop inputs/services among CropLife 100 ag retailers. In 2015, for Read More
Latest News
Crop InputsBayer Contests EPA’s Decision On Valuable Insecticide F…
February 5, 2016
Crop Science, a division of Bayer, has announced it has refused a request by the Environmental Protection Agency (EPA) to Read More
Wheat Field North Dakota
Seed/BiotechSyngenta Wins Seed Fraud Suit Against South Dakota Grow…
February 5, 2016
Syngenta has obtained a $25,000 settlement from Paul and John Mayclin, Mayclin Farms, Plankinton, SD, in response to their Plant Read More
ManagementOABA Annual Conference Wraps Up In Columbus
February 5, 2016
More than 300 Ohio AgriBusiness Association (OABA) members and industry professionals were on hand to engage in collaborative learning and Read More
Crop InputsBayer To Contest EPA Flubendiamide Decision
February 5, 2016
Crop Science, a division of Bayer, announced today it has refused a request by EPA to voluntarily cancel the uses Read More
Syngenta
Seed/BiotechNot So Fast: ChemChina Syngenta Takeover Could Draw Nat…
February 5, 2016
State-owned China National Chemical Corp. (ChemChina), which plans to buy Swiss seeds and pesticide maker Syngenta, will promptly start preparations Read More
Rendering of Syngenta Seedcare Institute expansion
Seed/BiotechExpansion Of Syngenta’s North America Seedcare In…
February 4, 2016
As demand for seed treatment knowledge and products grows among farmers, retailers and others in the seed industry, Syngenta is Read More
Soybean Field
Industry NewsArysta LifeScience Strengthens Sales Team
February 4, 2016
Arysta LifeScience North America recently announced three new personnel additions: Jake Cook and Peter White are Territory Sales Managers for Read More
Davor Pisk Syngenta COO
Crop InputsSyngenta COO: Why ChemChina Offer Beat Monsanto’s
February 4, 2016
Syngenta Chief Operating Officer Davor Pisk says he is confident the proposed acquisition by ChemChina will ultimately help preserve choice Read More
Young corn plants in soil
Crop InputsKoch Biological Solutions Invests In Pathway Biologic
February 4, 2016
An affiliate of Koch Biological Solutions, LLC has acquired a minority equity position in, and entered into collaboration with, Pathway Read More
Crop InputsABG: China Signs Off On Monsanto’s Roundup Ready …
February 3, 2016
Monsanto Co. on Wednesday announced it plans to launch its Roundup Ready 2 Xtend soybeans in time for the 2016 Read More
Syngenta headquarters in Basel, Switzerland
Crop Inputs6 Things To Know About The ChemChina-Syngenta Deal
February 3, 2016
After months of rumors and speculation, Syngenta has announced that ChemChina has offered to acquire the Swiss-based company. “In making Read More
FertilizerPhosphorus: Is Band Or Broadcast Application The Better…
February 3, 2016
Is band or broadcast application the better method when it comes to phosphorus? The answer to this question depends mostly Read More
Syngenta Sign
Crop InputsChemChina Nearing Deal To Buy Syngenta For Record $43 B…
February 3, 2016
China National Chemical Corp. is nearing an agreement to buy Swiss pesticide-and-seeds-maker Syngenta AG for about 43.7 billion francs ($42.8 Read More
Herbicides2015 ASA Trials Demonstrate Valent Fierce XLT Herbicide…
February 2, 2016
Valent U.S.A. today announced that new Fierce XLT Soybean Herbicide ranks in the top tier among growers for length of Read More
Crop Protection Products in storage
Paul SchrimpfCrop Input Selling: Return Of The Price List
February 2, 2016
It was a good 15 years ago, shortly after I first started writing for this esteemed publication, that it all Read More
Potash storage at Growmark
FertilizerThe Phosphate And Potash Outlook For 2016
February 2, 2016
Like other commodities, prices of the leading plant nutrient products dropped sharply in 2015. At this writing, the price of Read More
Chesapeake Bay
StewardshipKeeping A Watch On Water Issues
February 2, 2016
During a down cycle in the market, it’s difficult to think about investing for the long term. For retail businesses, Read More
Young Corn Plants
FertilizerNutrient Considerations For Low Corn Prices
February 2, 2016
Corn prices are low and many producers are asking tough questions about their nutrient management programs. Here are some suggestions Read More