Written with contributions by Emmanuel Byamukama, former SDSU Extension Plant Pathologist.
Goss’s bacterial wilt and leaf blight of corn, also known as bacterial leaf freckles and wilt, is an important disease of corn. The disease was first identified in Nebraska in 1969 and then in South Dakota in 1974. This disease is now found in several major corn producing states in the United States In years of heavy infection, it can lead to severe yield losses in susceptible corn hybrids.
January 24, 2025
Tar spot is a potentially yield-impacting corn disease that was confirmed in 46 of South Dakota’s 66 counties in 2024. The fungus can cling to crop residue over the winter and re-emerge once temperatures rise. It’s most commonly spread in South Dakota by wind-blown spores.
In late September, a sample received from Deuel County was confirmed positive for corn stunt, a disease spread through corn leafhopper feeding. This diagnosis is the furthest north corn stunt has ever been confirmed and reported in the United States.
In late October, tar spot was identified on dried field corn being sold for decoration at a big box store in eastern South Dakota. This fungal disease can be identified by the black lesions that are on both sides of the leaf.