Pythium Blight Greasy Spot

Lawn Problems

Pythium blight, also known as grease spot, can be a highly destructive lawn grass disease, especially on rye grasses. Severe outbreaks can completely destroy the lawn grass within a few days if weather conditions favour disease development.

Identify the problem
Grass leaves appear water-soaked in appearance at first, then shrivelled. Affected patches fade to a light brown or grey or black colour. Groups of affected spots frequently join together to form a large affected patch. At times, the shape of the areas may resemble elongated streaks. Both the presence and pattern of these streaks seem to be determined by the flow or presence of surface water. In high humidity during early morning or through the day, diseased leaves may be covered with the white, cobweb, growth of the Pythium fungus.
How to solve the problem
- Apply LawnPro Fungus Control to affected turf and at least 1 metre around.
- LawnPro Mossclear can be used to control spread of greasy spot and red thread in lawns. It will kill the spores of the fungus and prevent spread.
- Fungal diseases on lawns are exacerbated by stress caused by draught, poor drainage, low soil fertility, soil pH and excessively low cutting. Try to address any ways that your lawn may be under stress; improve drainage if over wet, water if over dry, adjust soil pH to 6.5-7.0 or raise the cutting height of your lawn mower.
- To repair damaged areas apply LawnPro Smart Patch Mix, LawnPro Smart Lawn Seed or LawnPro Lawn Thickener to the affected areas.
- Apply LawnPro D-Thatch to reduce the excessive lawn thatch that may have encouraged the Pythium fungus.
Did you know?
- Pythium greasy spot is caused by Pythium aphanidermatum