Brown Patch

Brown Patch in turf is caused by Rhizoctonia solani. Susceptible Turfgrasses include Wintergrass, Couch, Bentgrass, Fescues, Kentucky Bluegrass, Ryegrass & Buffalo Grass. Symptoms include brown discoloured circular patches, from a few centimetres up to a metre in diameter, sometimes with a smoke ring of mycelium around the edges. Smoke rings appear as thin brown borders around the diseased patches appearing in the early morning. Infected leaves are water-soaked and dark, later dying and turning dark brown. After the infected leaves die, new leaves can emerge from the surviving crowns. On wide bladed species, leaf lesions develop with tan centres and dark brown to black margins. Conditions favouring the disease are high relative humidity and temperatures of over 28°C during the day and over 15.5°C at night, more than 10 hours a day of foliar wetness for several consecutive days.