Symptoms
& Signs: |
Initially tiny, circular, dark spots
Spots enlarge and turn purplish
Later, centers of spots become light brown
Lesions on leaf sheaths cause girdling and collapse of plant
Crown rot causes thinning of turf ("melting out")
|
Grasses
Affected: |
All cool season grasses: common types of Kentucky
bluegrass most susceptible
|
Causal
Agent(s): |
Fungus: Helminthosporium spp.
Primarily H. vagans and H. sativum
|
Time of
Occurence: |
Fall and spring
|
Conditions that
Favor Disease: |
Cool air temperature
Overcast skies
Moist conditions
Improper mowing
|
