Annual bluegrass (a
common weed in turf), Kentucky
Lawns infested with Fusarium blight have small, circular grayish
to straw-colored areas of dead grass. These circular spots may range
from a few inches up to a foot in diameter. Some plants in the center
may survive, giving the turf a frog-eye appearance. The crown or
basal area of dead stems has a reddish rot and is hard and tough.
The dead foliage appears straw-colored.
Conditions favoring disease
Daytime temperatures of 85° to 95°F favor Fusarium blight.
Drought-stressed areas in full sun are most likely to exhibit the
disease. Fusarium blight survives in thatch and grass residues.
Prevention and management
Follow proper fertilization and irrigation
requirements for your turf species. When overseeding bluegrass,
use a mixture of 20% perennial ryegrass. Mow at the highest recommended
height for your turf species. Dethatch if
you have a thatch layer more than 1/2 inch (1.2 cm) thick. Consider
replanting with other turf
species that are not susceptible to Fusarium blight. Fungicides
are available but do not give complete control in California. If
used, make spring applications before or just after symptoms appear.
For more information on lawn diseases, refer to:
Pest Notes: Lawn Diseases:
Prevention and Management