Microdochium Patch

Susceptible turfgrass: Bluegrass, fescue, bentgrass, couch and perennial ryegrass.

Symptoms

• Early water soaked circular spots (less than 5 cm).
• Colour changes orange brown - reddish brown - light grey or tan (no more than 20cm).
• Closer inspection reveals water soaked dark margins in active spots.
• May be confused with Pythium blight lesions.
• Streaks easily - mower / run-off water.
• Infection will rarely progress to crown or kill plants completely.
• Humid, cool conditions may see the development of white mycelial growth and ultimately pinkish sporodochia.

Conditions favouring disease

• 1 - 15ºC with free leaf moisture.
• Disease development speeded up dramatically after initial infection.
• Low humidity & higher temperatures slows development down.
• Most severe on poor drainage areas - higher mowed turf which becomes matted down.
• Disease severity enhanced by deficiencies in potassium and elevated nitrogen levels.

Integrated turf management

• Maintain adequate fertility levels especially potassium.
• Increased N in spring & autumn may aggravate.
• Counter possible factors contributing to slow turf growth.
• Counter possible factors contributing to bad drainage.

Fungicidal control

Banner, Heritage have a label recommendation for Fusarium patch in South Africa.