Soil crusting is a classic mimic. Stunting plus pruned roots, purplish shoots possible. ALS-inhibiting herbicides such as Broadstrike or Hornet. The severity of injury can be increased with certain applications of organophosphate insecticides. Carryover from late season Pursuit applications from last year's soybeans could also be considered.
Soil compaction is a mimic.
Stunting plus pruned roots with clubbed root tips, purplish shoots possible. Corn roots growing in Prowl treated soil will be stunted. Therefore, Prowl should never be incorporated and corn should be planted at least 1.5 inches deep so the roots develop below the Prowl treated soil. Needle nematode is a mimic and causes pockets of damage in fields with sandy soil. Several cases have been reported in Wisconsin.