These plants are from a soybean field in southeast Carroll county.   Many other fields in eastern Carroll county showing similar symptomology.  This area was very dry from mid June to mid August.  A heavy rain (3 - 5 inches) occurred seven days ago. The problem fields have shown up just in the last two to three days, and in this particular field, the dead plants and chlorotic plants have covered most of the field in this short time period.

Growth stage R5.5 to R6

Symptomology
Yellow and chlorotic leaves (leaf tissue and veins), starting at top of plants and progressing downward
Small patches in the field with completely dead plants, leaves still attached to plant. 
The near dead and dead plants have very distinctive vascular discoloration (I would assume either phytophthora or brown stem rot).  Yet many of the plants just beginning to show yellowing in the upper canopy do not exhibit any stem discoloration.  
Infection of plants started and is worst in low areas of the field, but is advancing over ridge tops now.
I did not find any nematode injury
I noticed that all nodules were rotten or brown, even on healthy plants
On some plant roots, I noticed white hyphal growth.  (The ground is very wet)

Field history
Seeded May 13
Variety = Croplan 2454

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This page last updated on 07/21/03

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