Brown patch is a turfgrass disease that is caused by the Rhizoctonia species fungus. This turfgrass disease is most common Brown patch can be patch management policy pdf in all of the cool season turfgrasses found in the United States. Brown patch is known as a foliar disease, so it does not have any effect on the crown or roots of the turf plant.
Symptoms on turfgrasses that are wet for extended periods and are closely mowed will produce a distinctive gray-purplish bordered ring “smoke-ring” that is up to 50 cm in diameter. While on taller cut grasses that are not wet for extended periods of time will begin to produce patches that can be several feet in diameter and may have a “frogeye” appearance. White mycelium can be found on dew-covered turf in the early part of the morning. F but can survive in freezing temperatures.
F and during extended periods of high humidity or prolonged leaf wetness. The Rhizoctonia species has two specific fungi that affects the turf plant at different times of the year. In most cases Rhizoctonia solani will cause Brown patch in June throughout early July.