Tar spot of corn on a dried corn leaf. Credit: Domini Brown
Background
Corn is the most valuable crop in Minnesota and much of the Midwestern US. Many diseases impact production and quality of corn grain, but tar spot (caused by the fungus Phyllachora maydis) has become one of the most damaging. Tar spot was first detected in Minnesota in 2019, has spread to 55 counties, and is an increasing threat to corn production. It can be partially managed using fungicides and tar spot tolerant corn hybrids, but yield and economic loss still occurs.
Although some information has been uncovered about tar spot since its discovery in the US, other essential information is unknown. For example, the disease cycle, modes of dispersal of the pathogen, and the influence of different environmental and biotic conditions on the pathogen and disease are poorly understood. This project will build on recent research and address key information gaps related to disease risk and management of tar spot.
Research questions
- What are the biotic and abiotic factors that influence survival, spread, and pathogenicity of the tar spot pathogen?
- Do microbes on and in corn leaves influence development of the disease?
Practical implications
This research will lead to enhanced understanding of risk and management of corn tar spot, and may lead to novel approaches to managing the disease.
Findings
This project began in January 2026 and is in progress for the next several years. Please check back at a later time for updates.
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