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Cochliobolus carbonum (maize leaf spot )
Cochliobolus carbonum
maize leaf spot
Bipolaris zeicola, Drechslera carbonum, Drechslera zeicola, Helminthosporium carbonum, Helminthosporium zeicola
Worldwide
Eastern and Midwestern United States
2025-12-23
fungus
Korea
Main: corn; Other: rice
COCHCA
Cochliobolus carbonum is a fungal pathogen of maize that causes leaf spot. It survives on infected crop residue and spreads primarily by airborne spores, with disease development favored by warm temperatures and extended leaf wetness.
Crops
Zea mays
corn
No
COCHCA-2, COCHCA-4, CABI CPC, COCHCA-5, COCHCA-6, COCHCA-7, COCHCA-8
Cochliobolus carbonum affects maize worldwide, infecting leaves, leaf sheaths, husks, and occasionally ears, where black velvety mycelium and kernel discoloration may occur. The species comprises five races that differ in pathogenicity, symptoms, and toxin production. While the fungus can survive on maize residue and kernels and has been found at low levels on seed, there is no scientific evidence of seed transmission, so seed is not considered a pathway.
Yes
Freezing blotter method
NSHS METHOD: Mz 2.1 ISU Freezing Blotter Method (McGee 1994) (formerly Cf 2.1)
NSHS METHOD: Mz 2.1
COCHCA-3, NSHS USDA
Biological, Chemical, and Cultural
Resistance to race 1 is known. Fungicide seed treatements are effective. Crop rotation.
COCHCA-4, CABI CPC
2025-12-23 14:16:29
COCHCA-2
Koehler B, 1959. Corn ear rots in Illinois. Ill. Agric. Exp. Stn. Bull 638
COCHCA-4
McGee, DC. 1988. Maize Diseases: A reference Source for Seed Technologists. APS Press, St. Paul, MN USA. 150 pp.
CABI CPC
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
COCHCA-5
Munkvold, G. P., & White, D. G. (2016). Back Matter. In Compendium of Corn Diseases, Fourth Edition (pp. 147-165). The American Phytopathological Society.
COCHCA-6
Kang, I. J., Shim, H. K., Roh, J. H., Heu, S., & Shin, D. B. (2018). Simple detection of Cochliobolus fungal pathogens in maize. The plant pathology journal, 34(4), 327.
COCHCA-7
Dodd, J. L., and Hooker, A. L. 1990. Previously undescribed pathotype of Bipolaris zeicola on corn. Plant Dis. 74:530.
COCHCA-8
Hamid, A. H., Ayers, J. E., and Hill, R. R., Jr. 1982. The inheritance of resistance in corn to Cochliobolus carbonum race 3. Phytopathology 72:1173-1177.
COCHCA-3
Seed Health Testing Method for Cochliobolus carbonum Mz 2.1 National Seed Health System, 2019. www.seedhealth.org
NSHS USDA
United Stated Department of Agriculture, Animal and Plant Health Protection Service National Seed Health System (USDA-APHIS NSHS) www.seedhealth.org
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