Red Thread

Cool season turf

• Circular or irregularly shaped, small to large patches (5 to 15 cm) in diameter of infected grass become water-soaked and die rapidly
• First symptom is the tan colour of dead leaves.
• Dead leaves are interspersed amongst uninfected leaves giving an overall diffuse, scorched or ragged appearance to the patch.
• Only the foliage is infected and death usually proceeds from the leaf tips downwards.
• Pink to pale red or orange fungal growths (red threads) may extend up to 10 mm beyond the leaf tips.
• Pink, cottony flocks of mycelium may be produced.
• When red threads or flocks are present, the patched of blighted grass take on a reddish, pink or tan cast that is easily detected.

• Foliar wetness, heavy dews, light rains and fog resulting in more than 10 hours a day of foliar wetness for several consecutive days.
• Thrives in temperatures between 17°C to 29°C.
• Severe when potassium, phosphorus, calcium and nitrogen are deficient.
• Red Thread causes disease primarily during periods when grass is growing slowly as a result of low temperatures, drought or inadequate fertility.

• Mow turf frequently and collect clippings to remove diseased portions of the leaves.
• Maintain adequate nitrogen and a balanced fertility.
• Apply moderate to high amounts of phosphorous and potassium.
• Maintain the soil pH between 6.5 and 7.0.
• Reduce shade.
• Increase the air circulation to the turf.
• Irrigate turf deeply and as infrequently as possible.
• Avoid frequent watering in the late afternoon.

This disease is particularly difficult to diagnose when Red Threads or cottony flocks are not present.