It is much more severe on susceptible sweet corn and popcorn hybrids than on most field corn hybrids. The bacterial wilt organism infects sweet corn plants at any stage of growth. Infected seedlings may die prematurely. The disease is usually most conspicuous and serious in young plants under two feet tall. In seedlings, the bacterium often spreads systemically throughout plants of susceptible hybrids.
Symptoms are limited to localized areas of leaves in hybrids with moderate levels of resistance.
Several streaks on a leaf cause it to shrivel, and die. These symptoms may be confused with symptoms of frost damage, drought, nutrient disorders, or insect injury. The streaks can often be traced back to flea beetle wounds, usually on the top half of the leaf. The streaks later become dry and brown. On extremely susceptible hybrids, plants are stunted and die prematurely.