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 100Wheat Growers, North Central Farmers Elevator Pursue Merger
March 3, 2015
Two CropLife 100 retailers — South Dakota Wheat Growers (ranked No. 11) and North Central Farmers Elevator (No. 19) — have entered into a Letter of Intent to unify the two companies into a newly named cooperative. Read More
Growmark Group
CropLife 100GROWMARK In 2015: Back, To The Future
March 2, 2015
The nation’s third largest ag retail organization is simultaneously moving forward while remembering its past. Read More
CropLife 100Pinnacle Expands Sanders Brand In The South
February 27, 2015
Pinnacle has acquired Hopkins Seed and Chemical in Qulin, MO, which expands the company's Sanders brand to nine Southern states. Read More
CropLife 100Pinnacle Launches New Providence Agriculture Location In Indiana
February 27, 2015
Pinnacle Agriculture Holdings — ranked No. 6 on the CropLife 100 — has established a new retail location in New Castle, IN, which will operate as part of Pinnacle's Providence Agriculture brand. Read More
CropLife 100Cooperative CHS Returns $518 Million To Owners
February 23, 2015
The 2015 cash return to owners is based on CHS net income of $1.1 billion, the company's second highest on record. Read More
corn field
CropLife 100The Andersons’ Humic DG Now Available In Canada
February 13, 2015
The Andersons, Inc. Turf & Specialty Group has announced its Humic DG product is now available to customers in the Canadian turf, agriculture and horticulture markets. Read More
Latest News
CropLife 100Wheat Growers, North Central Farmers Elevator Pursue Me…
March 3, 2015
Two CropLife 100 retailers — South Dakota Wheat Growers (ranked No. 11) and North Central Farmers Elevator (No. 19) — have entered into a Letter of Intent to unify the two companies into a newly named cooperative. Read More
Equipment10 Tips for Spring Planter Preparation
March 3, 2015
Kinze Manufacturing offers advice on how to ensure your planter is ready before you hit the field. Read More
Industry NewsOABA 2015 LAUNCH Program Recognizes 20 New Graduates
March 3, 2015
Twenty Ohio agribusiness leaders are being recognized as the latest graduates of Ohio AgriBusiness Association’s LAUNCH program. Read More
EquipmentNew AGCO Website Helps Customers Shop For Certified Pre…
March 3, 2015
RoGator sprayers are among the wide range of CPO equipment available through AGCO's site. Read More
Enlist spray Demo
HerbicidesGuiding New Herbicide Systems’ Launches
March 3, 2015
Under careful watch, the new 2,4-D- and dicamba-tolerant crops hit more acres this season. Read More
Eric SfiligojCommodity Classic 2015: Playing The Waiting Game
March 2, 2015
There was plenty of future-talk at this year’s event as companies (and growers) are largely in a holding pattern of sorts. Read More
Industry NewsHighway Equipment Appoints New Director Of Business Dev…
March 2, 2015
Cory Venable, who joined Highway Equipment Company (HECO) in 2013 as OEM Account Manager, has been promoted to Director of Business Development. Read More
Prairieland FS employees
Eric SfiligojWorkforce Worries
March 2, 2015
Finding good employees almost always ranks as the No. 1 or No. 2 problem for ag retailers in our annual CropLife 100 survey. Read More
Growmark Group
CropLife 100GROWMARK In 2015: Back, To The Future
March 2, 2015
The nation’s third largest ag retail organization is simultaneously moving forward while remembering its past. Read More
CropLife 100Pinnacle Expands Sanders Brand In The South
February 27, 2015
Pinnacle has acquired Hopkins Seed and Chemical in Qulin, MO, which expands the company's Sanders brand to nine Southern states. Read More
CropLife 100Pinnacle Launches New Providence Agriculture Location I…
February 27, 2015
Pinnacle Agriculture Holdings — ranked No. 6 on the CropLife 100 — has established a new retail location in New Castle, IN, which will operate as part of Pinnacle's Providence Agriculture brand. Read More
2,4-D Celebrates 70 Years; GROWMARK Uses Super Bowl Ad To Share Positive Message
Management2,4-D Celebrates 70 Years; GROWMARK Uses Super Bowl Ad …
February 27, 2015
Jim Gray, executive director of the 2,4-D Research Task Force, lays out planned activities to mark the chemistry’s 70th anniversary. Read More
HerbicidesUniversity Of Arkansas Flag The Technology Program Adds…
February 27, 2015
Started in 2010, the Flag the Technology program provides a visual reference for applicators to distinguish between fields planted with different herbicide-tolerant trait technologies. Read More
Luckey Farmers, Inc.’s Berkey Farm Center
Industry NewsLuckey Farmers’ Berkey Branch Certified In 4R Nut…
February 26, 2015
The 4R Nutrient Stewardship Certification Program has announced Luckey Farmers Inc.’s Berkey Farm Center in northwest Ohio has been added to its growing list of nutrient service providers to achieve certified status. Read More
Crop InputsWinField Unveiling NutriVision Technology, Ascend Dry F…
February 24, 2015
New for 2015 are NutriVision Technology, a unique tool for monitoring in-season plant nutrient availability, and Ascend WSG plant growth regulator, a new dry formulation of Ascend plant growth regulator. Read More
FertilizerNew Formulation Of NutriSphere-N Protects High Volume U…
February 24, 2015
Verdesian Life Sciences is launching NutriSphere-N HVTM, a new polymer formulation of the proven NutriSphere-N Nitrogen Fertilizer Manager that protects high-volume applications of UAN. Read More
EquipmentIowa Ag Secretary Northey Names Hagie Water Quality Lea…
February 24, 2015
Iowa Secretary of Agriculture Bill Northey has named Hagie Mfg. as a recipient of the Secretary’s Water Quality Initiative (WQI) Leader Award. Read More
FungicidesEvito Fungicide Gives Canadian Wheat Growers New Diseas…
February 24, 2015
EVITO fungicide from Arysta LifeScience North America gives Canadian wheat and barley growers a new option for disease control. Read More