Date of this Version
Nebraska Extension NebGuide G2270
Northern corn leaf blight (NCLB) is a disease of corn caused by a fungus, Exserohilum turcicum (sexual stage Setosphaeria turcica). Its development is favored by cool to moderate temperatures and high relative humidity. Historically, NCLB has been more common and severe in states in the eastern Corn Belt, but its incidence has increased in Nebraska and the western Corn Belt in recent years. The disease is distributed throughout most of the corn-growing areas of the United States. The disease also occurs sporadically throughout other humid corn-producing areas of the world. In Nebraska, the disease has been most serious in the extreme eastern counties but is becoming increasingly common in central Nebraska during years when weather conditions are favorable for disease development. Yield loss caused by this disease can be extensive, up to 30–50 percent in susceptible hybrids when the disease develops early in the season, prior to tasseling. However, when disease severity is minor or its development is delayed until well after silking, yield impacts are usually minimal.