Lawn and Turf-Brown Patch

Hosts Bentgrass lawns are especially susceptible.

Cause A fungus, Rhizoctonia solani, that lives in soil and on diseased vegetation of nearly any kind. Brown patch is rare west of the Cascade Range and not common east of the Cascade Range. Hot (82°F or above) humid weather favors the disease.

Symptoms Brown, irregularly shaped or circular areas appear in grass and may enlarge from a few inches to several feet in diameter. Usually the margin of the patch has a darker ring 1 to 2 inches wide where the fungus is actively advancing. Crowns and roots generally are not killed.

Cultural control

• Avoid excessive irrigation and overstimulation with nitrogen (succulent growth is more susceptible to injury).
• Avoid over-irrigation as saturated soil conditions will accelerate disease development.
• Aerification practices (core cultivation and vertical mowing) that reduce organic-matter accumulation and improve drainage will reduce fungal activity.
• Wetting agents that promote water penetration or infiltration will also decrease fungal activity.

Chemical control Tolerant strains of many fungal pathogens can become troublesome when some fungicides are used exclusively in a spray schedule. To prevent developing resistant fungi, alternate or tank-mix materials from different groups with different modes of action. Limit the use of any one group during crop production.

Products available in home packaging:

• Actinovate Lawn and Garden (Streptomyces lydicus strain WYEC 108) at 10 teaspoons/5 gal water plus a wetting agent/1,000 sq ft as a soil drench. Do not mix with Regalia or certain copper- or sulfur-based products. Unknown efficacy. O
• BioAdvanced Fungus Control for Lawns at 32 fl oz/over 5,000 sq ft. Group 3 fungicide. H
• Infuse Systemic Disease Control at 5 fl oz/1 gal water/250 sq ft of lawn. Group 3 fungicide. H
• Spectracide Immunox Multi-Purpose Fungicide Spray Concentrate for Gardens at 7 fl oz/gal water over 500 sq ft. Group 3 fungicide. H

Products available for commercial use:

• Affirm WDG at 2.4 lb/A. Do not irrigate for 12 hours after application. Group 19 fungicide. 4-hr reentry.
• Chipco 26019 FLO at 4 fl oz/1,000 sq ft. Group 2 fungicide. 12-hr reentry.
• Compass 50 WDG at 0.1 to 0.25 oz/1,000 sq ft. Do not use organosilicate additives. Group 11 fungicide. 12-hr reentry.
• Daconil Weather Stik at 2 to 5.5 fl oz/1,000 sq ft depending on whether the application is preventive or curative. Group M5 fungicide. 12-hr reentry.
• Densicor at 8.5 fl oz/A or 0.196 fl oz/1,000 sq ft. Do not use hand held equipment. Group 3 fungicide. Reenter when sprays have dried.
• Disarm 480 SC at 0.09 to 0.36 fl oz/1,000 sq ft. Group 11 fungicide. 12-hr reentry.
• Fame SC at 0.1 to 0.4 fl oz/1,000 sq ft. Group 11 fungicide. 12-hr reentry.
• Eagle 20 EW at 1.2 fl oz/1,000 sq ft. May produce a growth regulation effect on Kentucky bluegrass. Group 3 fungicide. 24-hr reentry.
• Endorse WP at 11 lb/A. Group 19 fungicide. 4-hr reentry.
• Heritage at 0.2 to 0.4 oz/1,000 sq ft. Alternate with other fungicides. Group 11 fungicide. 4-hr reentry.
• Insignia SC at 0.4 to 0.7 fl oz/1,000 sq ft. Do not use with organosilicate adjuvants. Group 11 fungicide. 12-hr reentry.
• Mancozeb 80% (Fore, Manzate, and Protect DF) at 4 oz/1,000 sq ft. Group M3 fungicide. 24-hr reentry.
• Medallion SC at 0.75 to 2 fl oz/1,000 sq ft. Apply after mowing. Use with oils or adjuvants may cause plant damage. Group 12 fungicide. 12-hr reentry.
• Mirage at 1 to 2 fl oz/1,000 sq ft. Group 3 fungicide. 12-hr reentry.
• Monsoon Turf at 0.6 fl oz/1,000 sq ft. Group 3 fungicide. 12-hr reentry.
• Previa at 2 to 5.5 fl oz/1,000 sq ft. Group M5 fungicide. 12-hr reentry.
• Propiconazole-based products. Group 3 fungicides.
  • Banner MAXX at 1 to 2 fl oz/1,000 sq ft. 12-hr reentry.
  • PropiMax EC at 0.37 to 0.73 fl oz/1,000 sq ft. 12-hr reentry.
• ProStar 70 WG at 1.5 to 3 oz/1,000 sq ft. Group 7 fungicide. 12-hr reentry.
• Rayora at 0.7 to 1.4 fl oz/1,000 sq ft. Group 3 fungicide. Reentry after sprays have dried.
• Secure at 0.5 fl oz/1,000 sq ft. Group 29 fungicide. Reentry when sprays have dried.
• Spotrete F at 3.75 to 7.5 fl oz/1,000 sq ft. Group M3 fungicide. 24-hr reentry.
• Tebuzol 3.6F at 0.6 fl oz/1,000 sq ft. Group 3 fungicide. No reentry interval listed.
• Torque at 0.6 to 1.1 fl oz/1,000 sq ft. Do not mix with growth regulators during hot weather as injury may develop. Group 3 fungicide. 12-hr reentry.
• Tourney EZ at 0.28 to 0.37 oz/1,000 sq ft. Do not apply to Poa annua putting greens. Group 3 fungicide. 12-hr reentry.
• Trinity at 0.75 to 2 fl oz/1,000 sq ft. Do not mix with growth regulators during hot weather as injury may develop. Group 3 fungicide. 12-hr reentry.
• Turfcide 400 at 5 to 6 fl oz/1,000 sq ft. Irrigate with 0.25 inch water immediately after application. Do not use hand application equipment or mow for 1 day after application. Under certain growing conditions a temporary discoloration of the grass may occur. Group 14 fungicide. 12-hr reentry.
• Velista at 0.3 to 0.5 oz/1,000 sq ft. Group 7 fungicide. 12-hr reentry.
• Veranda T at 2.4 lb/A. Group 19 fungicide. 4-hr reentry.
• Xzemplar at 0.21 to 0.26 fl oz/1,000 sq ft. Group 7 fungicide. 12-hr reentry.

Combination Fungicides

• Armada 50 WDG at 0.6 to 1.5 oz/1,000 sq ft. Do not use a silicone-based surfactant. Group 3 + 11 fungicide. 12-hr reentry.
• Briskway at 0.5 to 1.2 fl oz/1,000 sq ft. Can be used in hot weather. Group 3 + 11 fungicide. Reentry when sprays have dried.
• Concert at 3.5 to 8.3 fl oz/1,000 sq ft. Do not use on fine fescue turf. Group 3 + M5 fungicide. 12-hr reentry.
• Encartis at 3 to 4 fl oz/1,000 sq ft. Do not use with oil-based pesticides. Group 7 + M5 fungicide. Reentry when sprays have dried.
• Exteris Stressgard at 2 to 6 fl oz/1,000 sq ft. Water in lightly after application. Group 7 + 11 fungicide. 12-hr reentry.
• Headway at 1.5 to 3 fl oz/1,000 sq ft. Do not use with silicone-based surfactants or EC formulations. Group 3 + 11 fungicide. 12-hr reentry.
• Heritage Action at 0.2 to 0.4 oz/1,000 sq ft. Group 11 + P1 fungicide. 12-hr reentry.
• Honor at 0.55 to 1.1 oz/1,000 sq ft. Do not use with organosilicone-based adjuvants. Group 7 + 11 fungicide. Golf course turf only.
• Instrata at 2.75 to 6 fl oz/1,000 sq ft. Do not use on fine fescue. See label for tank mix incompatibilities. Group 3 + 12 + M5 fungicide. 12-hr reentry.
• Interface at 3 to 5 fl oz/1,000 sq ft. Maintain agitation while spraying. Do not mix with adjuvants. Group 2 + 11 fungicide. 24-hr reentry.
• Lexicon at 0.34 to 0.47 fl oz/1,000 sq ft. Group 7 + 11 fungicide. 12-hr reentry.
• Navicon at 0.7 to 0.85 fl oz/1,000 sq ft. Group 3 + 11 fungicide. 12-hr reentry.
• Pillar G at 3 lb/1,000 sq ft. Group 3 + 11 fungicide. 12-hr reentry.
• Premion at 6 to 8 fl oz/1,000 sq ft. Group 3 +14 fungicide. Reentry when sprays have dried.
• Renown at 2.5 to 4.5 fl oz/1,000 sq ft. Group M5 + 11 fungicide. 12-hr reentry.
• Tartan at 1 to 2 fl oz/1,000 sq ft. Group 3 + 11 fungicide. 12-hr reentry.

Some registered products offer only suppression of this disease and thus are not recommended for use. These products include Pinpoint.

Biological control

• Zio (Pseudomonas chlororaphis strain AFS009) at 1.8 to 6 oz/1,000 sq ft. Was not effective in Maryland and of unknown efficacy in the PNW. 4-hr reentry. O

Reference Gross, M.K., Santini, J.B., Tikhonova, I., and Latin, R. 1998. The influence of temperature and leaf wetness duration on infection of perennial ryegrass by Rhizoctonia solani. Plant disease 82:1012-1016.