Yellow Tuft Disease

yellowtuft.jpg (40943 bytes) General view of yellow tuft disease.

This disease appears to be most common on bentgrass swards although all turf grasses can be affected.

Yellow Tuft (or Downy Mildew) is caused by the fungus Sclerophthora macrospora.

It is a disease that has increased in incidence over the last 5 years. 

The fungus enters the turfgrass plant through the wounds of the cut leaf after moving across and through a sward in surface water films.  Once inside the plant, the fungus causes the plant to tiller profusely and this, along with the resulting yellowing of the leaf tissues, gives this disease its common name.  Affected plants often have reduced rooting depth and can be easily picked from the sward. 

Once a plant is infected by this fungus, the fungus will remain within the plant, but the symptoms of the disease may not necessarily develop every year.

Wet, waterlogged rootzones are ideal for the development and spread of this disease.

It is not known if the nutritional status of the plant or the rootzone pH have any effect on disease incidence or severity.