Common Name: yellow tuft
Scientific Name: Sclerophthora macrospora

Yellow tuft, or downy mildew, is caused by the water mold fungus Sclerophthora macrospora. The disease occurs on most turfgrass species, but is most common in creeping bentgrass or annual bluegrass putting greens. The disease is most damaging in areas that are poorly drained, over-irrigated, or have excessive thatch accumulations. Symptoms of yellow tuft appear in small, yellow spots that are scattered across the turf stand. On occasion, the spots may appear to follow drainage patterns. Closer examination reveals that the yellow spots are slightly raised above the turf canopy. The affected plants will pull easily from the turf to reveal dense clusters of yellowed tillers emanating from a single crown. This profuse tillering if referred to as a “witches’ broom” symptom, and is caused by production of hormones by the pathogen in the crown of infected plants.
yellow tuft
[Click image to enlarge.]
  All Photos
Characteristic Description
Host Turfgrassbentgrass, bluegrasses, zoysiagrass
Month(s) with symptomsApril to September
Stand Symptoms (2)spots
Foliar Symptoms - Location/Shapeno distinct leaf symptoms
Foliar Symptoms - Coloryellow
Root/Crown Symptoms (2)none
Fungal Signsnone
View All Photos (4)

TurfFiles Logo© copyright 2000-2012 North Carolina State University
 TurfFiles is funded by the Center for Turfgrass Environmental Research & Education (CENTERE) through public and private grants.