Posts tagged ‘Soybean Sudden Death Syndrome’

How Soybean Sudden Death Syndrome Looks at the Root

Most agronomists and farmers are good at identifying soybean Sudden Death Syndrome (SDS) through leaf symptoms (below image courtesy of Glen Arnold, OSU Extension Putnam County):

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However, there is another diagnostic feature that can be used as well.  OSU’s Anne Dorrance will also use blue spores of the SDS fungus on a soybean tap root as a diagnostic feature.  This avoids incorrect diagnosis, that is, diagnosing brown stem rot or interveinal chlorosis from nutrient deficiency as SDS.

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Full podcast here:  

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August 24, 2010 at 12:07 pm 1 comment

Lookalike Soybean Diseases: Brown Stem Rot

Brown Stem Rot is one of the lesser abundant diseases in my area, and is often easily confused with soybean Sudden Death Syndrome (SDS).  I had the chance on September 11 to spend a few minutes in the field with Dr. Anne Dorrance while we examined my brown stem rot plots. Foliar symptoms, when present, consist of wilting, chlorosis, and browning of the tissue between the veins. These foliar symptoms are very similar sudden-death syndrome. Generally, the two diseases can be distinguished by looking at the soybean pith. With brown stem rot, a brown to reddish brown discoloration of the stem pith occurs and can be continuous throughout the stem from the base of the plant upwards.  If the pith appears healthy at first, give a second look for discoloration at the nodes.

When this disease does develop it tends to be in fields that have been in continuous soybeans, short rotations, reduced tillage, or no-till. When disease is severe, yield reductions from 10 to 38% have been reported. The fungus, Phialophora gregata, only infects soybeans and is also residue borne.

Crop rotation and soybeans with resistance are two of the main tools used to combat brown stem rot in soybeans.  Dr. Dorrance’s factsheet on the subject is available here: http://ohioline.osu.edu/ac-fact/pdf/0035.pdf

Anne Dorrance rating brown stem rot in soybeans-Van Wert County September 11, 2009

Anne Dorrance rating brown stem rot in soybeans-Van Wert County September 11, 2009

September 14, 2009 at 8:15 am

Soybean Sudden Death Syndrome

Reports across the midwest (Nebraska, Iowa, Kentucky)  indicate that soybean sudden death syndrome (SDS) is becoming prevalent in some areas.

Image courtesy Ohio Field Crop Diseases and Pat Lipps (retired).

The OSU Pathology group has an excellent resource on crop diseases available at the Ohio Crop Disease website.  Below is from the section on SDS:

Symptoms

  • begin as small pale green to yellow circular leaf spots
  • brown to tan areas develop between the veins
  • pith is white
  • root decay and discoloration of roots and crown

Environment

  • high soil moisture during late vegetative growth stages
  • SCN can increase severity of foliar symptoms

Survival

  • fungal spores overwinter and survive for years in the soil
  • spores have been found on the cysts of SCN

Management

  • reduce SCN populations
  • increase soil drainage by tiling or tillage
  • long crop rotations – soybeans only once every three years

Full podcast available here:

August 26, 2009 at 8:00 am

Soybean Sudden Death Syndrome Appearing

Soybean Sudden Death Syndrome symptoms are starting to show up, albeit in a very few fields. In this weeks’ podcast I discuss management of this soybean disease.

August 20, 2008 at 7:00 am 2 comments


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This blog is no longer being maintained. Information on this blog may still be relevant, but for the latest agronomic information and farm management information please visit http://corn.osu.edu and http://ohioagmanager.osu.edu, respectively.

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