Symptoms are described briefly. Stewart's Bacterial Wilt Yellow to brown streaks, occasionally up to 1-inch wide, develop on leaves and may extend the lengrh of the leaf. Brown discoloration and sometimes rotted cavities form in the center of the stem near the soil line. The disease is most prevalent following mild winters, especially in the southern and south-eastern parts of Pennsylvania. Smut Smut is characterized by presence of large fleshy, irregular galls on leaves, stems, ears, and tassels.
Smut is promoted by plant injury caused by cultivation, insects, and hail.
Rust and Leaf Spots Rust is characterized by reddish to brown rusty powdery areas on the top surfaces of leaves. These diseases can be significant, but usually only late in the season. Dispose of stalks and leaves as soon as harvest is over. Information provided is intended for consideration by the user, but is not intended to be a recommendation.