Habitat & Timing:
Affects many grass species, in humid and warm temperatures above 20°C, heavy dew, excessive fertility and poor drainage.
Brown patch survives and spreads by mycelium in debris and soil and it infects through wounds or direct penetration.
On closely mown turf, grey/brown circular patches (1cm to 50cm diameter), tissue becomes dark and water soaked, infected spots turn brown and die. Under warm, humid conditions, the affected patches will have what is called a 'smoke ring' around the edge of the affected turf. On taller grasses light brown patches form and often a close inspection reveals leaf lesions.