G1909

Brown Patch Disease of Turfgrass

Causes, symptoms and management of brown patch disease in turfgrass. This is one in a series of NebGuides on managing turfgrass diseases.

• Introduction
• Cause, Hosts, and Occurrence
• Key Symptoms
• Recommended Cultural/Maintenance Practices
• Fungicide Program

Figure 1. Brown patch lesions on tall fescue leaves. Note the irregular margin that does not extend across the grass blade.

Introduction

Brown patch is a common disease found mostly in tall fescue although it can affect all types of turf. Cultural practices are the first line of defense in managing brown patch; however, fungicides also effectively control this disease. The following information describes the disease and how to identify and manage it.

Cause, Hosts, and Occurrence

Cause: Rhizoctonia solani

Principal hosts: Ryegrasses, tall fescue, creeping bentgrass, Kentucky bluegrass

Occurrence: July – September

Key Symptoms

Tall-cut turf: Roughly circular patches of blighted grass with a reddish-tan color. Long, irregularly shaped leaf lesions surrounded by a dark brown margin (Figure 1).

Greens and fairway height: Diffuse, roughly circular, reddish brown patches up to 2 feet in diameter. Patches may have a smokey-gray outer ring.

Recommended Cultural/Maintenance Practices

• Avoid high nitrogen fertilizer applications during the summer. Feed turf with low rates of nitrogen to maintain moderate growth and good recovery from disease.
• Perform maintenance to improve air circulation across the turf.
• Avoid night irrigations.
• Reseed or overseed with turf species with higher tolerance.

Fungicide Program

Golf Courses: On bentgrass greens use the most effective products from early July through mid-August. Curative treatments should include a strobilurin or carboxamid product.

Home Lawn and Other Turfs: Use high label rates of propiconazole or thiophanate methyl to provide three to four weeks of protection. Treat areas prone to brown patch with a preventative when night temperatures are going to be above 75°F; other areas can be treated curatively as needed.

Fungicides for brown patch management are presented in Table I. An example product is listed for each active ingredient; other products also may be available. Homeowner and commercial product labels will list active ingredients. While the active ingredient may be in combination with others, users should look for a specific active ingredient with or without other chemistry modes of action.

This publication has been peer reviewed.

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Index: Plant Diseases
Turf
Issued February 2009