Stalks which lose their supporting roots because of this disease may be blown over easily. The diseased stalk usually shows a reddish discoloration when it is split open. There are no control measures except crop rotation, planting on well-drained soils, and proper nutrition. Corn infected with this disease is stunted and has wilted leaves on dry days. Brown streaks often appear along the leaf veins.
Leaves dry up rapidly, remaining grayish-green in color even though withered.
This ooze shows only after a rain or heavy dew. Plants infected as seedlings may be killed outright. Plants infected later may produce a satisfactory crop. The bacteria enter the field on seed or in the bodies of adult overwintering corn flea beetles. Because of the importance of the flea beetle in carrying over the bacteria from one growing season to the next, the severity of the winter is one of the factors which controls the amount of Stewart's wilt.