Mycosphaerella pinodes and Phoma medicaginis var. pinodella -
Seedling stem turn dark brown to black, often near the soil
line, seedlings may be killed or grow weakly - Small dark flecks
on stems, leaves and pods - Leaf spots grow into round brown
spots with several concentric rings like a bull's eye - Purplish
black lesions on stems - More information on Mycosphaerella
Blight...