Red Root Rot
Symptoms
- Red or pink discoloration of the root system and lower stalk tissue turns to a deep red to purple color along with death and shriveling
- Symptoms usually appear just before corn maturity
- The red color is deeper and darker than that of Gibberella stalk and root rot
- Symptoms vary among different corn genotypes
- Root mass can be reduced
- The rotting below ground can lead to wilting and grayish green foliage, premature plant death, and lodging in 4 to 5 days
Pathogen Involved
- Phoma terrestris (fungus) in association with Pythium and Fusarium species
- Survives in soils with a wide range of temperature and pH conditions
- The pathogen overwinters as microsclerotia in soil
- This disease has had a high incidence in the Atlantic states and Delmarva region of the U.S.
Time of Occurrence
- Occurs as early as midsilking stage, but mainly late in the growing season
Conditions Favoring Disease
- As the plant senesces, the rate of disease development increases
- Moderate temperatures: (~75-80°F)
- High yield environment (=high populations, high fertility, and irrigation)
Disease Management
- Rotation with soybeans may provide some benefit