Winter Fusarium

Winter Grass, Bent Grass, Fescue, Ryegrass and Kentucky Blue Grass

• Circular patches appear as small, water-soaked spots less than 5 cm in diameter.
• Patches change in colour from orange-brown to dark brown and finally to a light gray.
• Spots may enlarge indefinitely, but are usually less than 20 cm in diameter.
• On low-cut turfs, ring like patches "smoke rings" may appear, the outer ring of the patch may have a water-soaked, greenish black margin.
• In very wet conditions a thin to fluffy covering of white mycelium may be seen on matted leaves.
• The mycelium is white, but on exposure to sunlight induces spore production which is a pink colour.

• More than 10 hours a day of foliar wetness for several consecutive days.
• Cool temperatures.
• Soil high in nitrogen fertility and low phosphorous and potassium.
• Areas with slow growing conditions and heavy thatch.

Maintain balance fertility.
Avoid using lime. Alkaline soils enhance disease development.
Maintain low soil pH.

• Use slow release fertilisers when fertilising in autumn.
• Increase air circulation to speed turf's drying process.
• Minimise the amount of shade.
• Avoid excessive thatch.

Symptoms are evident from May to September in the southern states of Australia.