Mz 13.1 Cercospora zeae-maydis2018-04-25T13:18:34-05:00

National Seed Health System

Mz 13.1   Cercospora zeae-maydis

DATE: 2001
PATHOGEN:  Cercospora zeae-maydis (syn: Cercospora sorghi var. maydis; Mycosphaerella sp.)
HOST: Maize (Zea mays)
COMMON NAME: gray leaf spot (GLS)
METHOD: Mz 13.1 Culture Plate (formerly Cf 10.1)
SAMPLE: : 400 seeds


1. Randomly select 400 seeds; 4 replicates of 100.

2. Wash thoroughly in running water to remove chemical seed treatment.

3. Immerse seeds in 1.0% (v/v) solution of sodium hypochlorite for 3 minutes. Triple rinse with sterile water.

4. Aseptically place seeds on PDA (potato dextrose agar), usually 5 to 10 seeds per petri plate.

5. Inoculate one PDA plate per replicate with a known culture of C. zeae-maydis

6. Incubate samples at 25°C with 12 hours of light per day for 7 days.

7. Examine the plates for colonies typical of C. zeae-maydis.

8. Suspect mycelium and/or fruiting bodies should be examined under magnification to confirm the identity.


McGee, D. C. 1988. Maize Diseases. APS Press, St. Paul, MN.

CABI. Crop Protection Compendium