Species category: Root Diseases
Scientific name: Rhizoctonia solani
What is Brown Patch?
Brown Patch first appears as a circular patch which can range in size from a few centimetres up to a metre in diameter.
At first, affected leaves become water-soaked and dark, they have a purplish green appearance as the disease takes hold. The leaves quickly die and turn dark brown. In periods of high humidity, a “smoke ring” of mycelium appears on the outer ring of the patch. This is indicated by a dark-brown, slightly grey ring on the outer edge of the patch.
When does Brown Patch occur?
This disease occurs on cool season turf grass species when temperatures reach between 15-20°C, the spores germinate and begin to grow. When night temperatures are consistently above 20°C and moisture or humidity is high, the disease becomes most damaging.
Warm season turf is also severely affected, but the ideal weather conditions for Brown Patch are unknown.
It appears most severe in spring and autumn when humidity can be higher with less likelihood during dry summer months. It is also worse in soils that struggle with drainage or soils that are over-irrigated, where the leaf wetness encourages Brown Patch development.
What damage or effect will Brown Patch have?
The most widespread of all turf grass diseases. It is not commonly seen outside of closely mown areas.
The disease can take hold in a few hours and can ruin the aesthetics of the turf. In more severe cases, grass cover will be affected.
How to eliminate Brown Patch from Turf