Rhizoctonia brown patch is the most common and important disease on which grass?

• A. Tall fescue
• B. Bermudagrass
• C. St. Augustine
• D. Kentucky bluegrass

Answer: (A)

Rhizoctonia brown patch is a fungal disease that shows up when the weather is warm and humid and the turf canopy stays wet for long periods. Tall fescue is especially prone to this disease because its growth habit forms dense, lush patches that trap leaf moisture, creating ideal conditions for Rhizoctonia solani to infect and spread. In many Kansas-type climates and cool-season lawns, brown patch tends to appear and spread most noticeably on tall fescue, making it the grass where this disease is seen most often and can cause the most turf loss if not managed. You’ll typically notice irregular brown patches that can merge into larger areas, often with the outer edge still green as the plant keeps growing. Managing it involves moderating nitrogen fertilization, scheduling irrigation to avoid prolonged leaf wetness, ensuring good air movement and turf drainage, and applying fungicides when necessary. Other grasses on the list can get brown patch too, but the disease is most commonly and seriously encountered on tall fescue.