Date of this Version
All corn hybrids and inbreds are susceptible to gray leaf spot in varying degrees. This NebGuide discusses the symptoms, impacts and management of this disease.
Corn is grown throughout Nebraska on over 8 million acres of land; approximately 5 million acres are irrigated. The market is segmented into seed corn, field corn and specialty corns (e.g., high oil, high amylose and white corn). Field corn represents the largest portion of the acreage grown. To varying degrees, all corn hybrids and inbreds are susceptible to gray leaf spot disease.
Gray leaf spot is a significant disease worldwide. It has been present in the United States since 1925 and has been considered a problem in the mid-atlantic states and the eastern midwest region of the Corn Belt for decades. Gray leaf spot has been present in Nebraska since at least 1986. However, significant yield losses have occurred over a wide area only since 1994. Unique weather patterns since 1992 (cooler temperatures and prolonged periods of overcast days); changing crop residue management practices (increased acreage of reduced tillage management); and the cultivation of new high-yielding hybrids all may have contributed to the increased prevalence and severity of gray leaf spot in Nebraska.