Affected leaves turn a gray-green colour which resembles frost damage. All three cause a dark external lesion or spots at the lower nodes. These spots are hard to remove. This is in contrast to Gibberella which also produces small, round, black spots at the lower node except these spots can be easily scraped from the stalk surface. The pith is shredded and has a pink to red colour.
Fusarium stalk rot symptoms appear as a light brown-black lesions near the nodes.
Internal stalk symptoms of Fusarium is a salmon-pink fungal growth in the pith. European corn borer injury has benefited stalk rot and ear mould development this year. This is especially true when examining Bt and non-Bt hybrids. The incidence of stalk and ear rots that occur at entry or injury points as a result of European corn borer feeding has been dramatically reduced this year. At this time of year, little can be done to reduce stalk rot development other then minimize losses to lodged or broken stalks.