Check at least 100 plants per field, in different locations. Different hybrids and fields with different tillage, rotation, or fertilization histories should be scouted separately. If a field has more than 10-15 percent of the stalks rotted, significant lodging is likely. Prior to black layer, it is difficult to distinguish among the different stalk rot fungi. Any stalk rot can result in wilting and death of the plants.
Leaves turn a gray-green color as they die, similar to frost damage.
There may be dark external lesions at the lower nodes, and internally the stalk base will be dark brown and decayed. Later in the season, the stalk pith appears shredded and discoloration can become obvious in the pith and on the rind. Stalks infected with anthracnose will eventually become very discolored, and they may be showing initial stalk lesions now. High levels of stalk rot susceptibility are a result of plant stress. Many types of stress can influence stalk rot, including inadequate soil moisture or excessive soil moisture.