Brown blight (BB) is caused by the fungus Drechslera siccans. It is most common in spring and autumn but damage can occur all year.
Ryegrass, fescue, cocksfoot.
BB causes leaf lesions of various shapes and sizes. These consist of small, oval, brown spots, the centres of which become light brown to white as they enlarge. Longer, dark brown streaks also appear. Infected leaves turn yellow and die from the tips.
BB survives on dead and diseased plant tissue. It is spread by wind, rain, equipment or animals. In moist conditions, spores germinate, causing new infections.
Prevention and management
Timely cutting and grazing minimise damage from BB. Fungicides can minimise damage but profitability is questionable.
Brown blight on ryegrass leaves.