While all hybrids tested thus far are susceptible to some degree, certain hybrids are probably too susceptible for use in an infested field. Producers can often learn much about a corn hybrid from observations in commercial fields and from inspections of strip trials, where hybrids are planted in strips running the length of the field. However, use caution in judging the susceptibility of a hybrid from one such observation, regardless of the difference in incidence of Stenocarpella ear rot among hybrids. Spore levels may differ from field to field and even within a field. Furthermore, spore levels and weather conditions that promote infection vary from week to week.
Corn plants are most susceptible around silking.
Unless the corn hybrids being compared flowered at about the same time and were exposed to the same spore levels, comparing the disease level among hybrids in a strip trial or in different fields may be misleading. Current research at the University of Kentucky suggests that it is very difficult to make meaningful comparisons among hybrids under field conditions, even using rigorous methods of experimental design. Such comparisons are even more difficult when evaluating the level of Stenocarpella ear rot among single hybrid strips within a field or among different fields. To lessen the risk from this disease, consider planting several hybrids with differing maturities so that they won't all be silking simultaneously. Thus, even if an outbreak of Stenocarpella occurs, some fields may escape the disease.