If lesions have reached the ear leaf or higher during the
two weeks before and after tasseling, yield loss could
occur. Hybrid corn yield could be reduced as much as
30 percent if lesions are present prior to or at tasseling.
Yield losses in popcorn, sweet corn, or other specialty
corn production systems may be greater.
If lesions do not appear on upper leaves until late in the
season, yield losses will be less. Unfortunately, there is
not a clear relationship between the amount of leaf
tissue covered by lesions and the amount of yield loss,
so it is not possible to say that a given severity of disease
will result in a given loss of yield for any hybrid.
In addition to the potential for yield loss caused by a
loss of photosynthetic area, NCLB lesions can contribute
to stalk rot development and lodging.