Management practices 

• Imporve drainage of the turf.
• Increase the air circulation.
• Use proper surface contours to minimise water movement and accumulation on the turf's surface.
• Avoid high or excessive levels of nitrogen that result in lush growth.
• Promote active but not lush growth.
• Yellow turf symptoms can be masked with additional iron as the symptomatic areas will not disappear readily.

Fungicidal control

At present there are no Syngenta fungicides with label recommendation for control of yellow tuft in turf.

DOWNY MILDEW (YELLOW TUFT)

Causal Agent

Sclerophthora macrospora

Susceptible Turfgrass

All cool season turfgrass species

Symptoms

• Early symptoms are slightly stunted growth and slightly thickened or broadened leaf blades without any discolouration
• When the disease is severe, small yellow circular patches 1 to 10 cm in diameter appears in the turf.
• Patches contain a dense cluster of excessively tillered yellow shoots with shortened root, which are easily pulled from the turf
• A white downy growth may occur on leaf surfaces during cool, wet periods.

Conditions Favouring Disease

• Downy Mildew initially occurs in wet, poorly drained areas that are depressed.
• The fungus likes warm temperatures (30 C to 35 C), humid or rainy weather when night temperatures are warm  (above 20 C)
• Relative humidity over 90% for over 10 hours with temperatures not dropping below 20 C.

General Comments          

• Downy Mildew symtoms are difficult to diagnose in mown turfgrass.
• Symptoms for Downy Mildew vary depending on the grass cultivar.
• The disese typically infects cool-season turf in early to later spring and mid to late autumn.
• Warm season grass are affected primarily during the humid weather of summer and can be more severe in shaded areas.
• Called Yellow Turf in some states.

Distribution

Victoria, New South Wales and South Australia.