Brown patch is a common
patch disease that affects several cool-season grasses .primarily tall fescue. Symptoms can appear quickly in warm,
humid weather, primarily when nighttime temperatures
exceed 70 F during heavy
conditions, fungal resting spores in the thatch begin to grow and rapidly
damage the susceptible turf. Symptoms may appear as circular brown patches
ranging from inches to several feet in diameter or as large blighted areas that
lack a distinct pattern. The circular patches often are bordered by a brown
band referred to as a smoke ring. Irregular,
tan lesions with a brown
border usually are visible on individual grass leaves. Mycelium often are
visible between grass blades in infected areas in the morning, especially in
the presence of dew.
COMMENTS on disease
Brown patch rarely kills the turfgrass crown,
which allows the turf to recover after favorable disease development conditions
In addition to favorable
weather conditions, brown patch development can be promoted by improper cultural
practices such as over fertilization, excessive leaf wetness caused by watering
lawns during the early evening hours and by allowing thatch to accumulate.
(azoxystrobin), Compass (trifloxystrobin), Bayleton (triadimefon) and Prostar
not over apply nitrogen fertilizer, avoid prolonged leaf wetness
by providing irrigation
deeply and infrequently in the morning or early afternoon, and prevent thatch buildup.