By Matt Giese, M.S., technical services manager for Syngenta

Brown patch is a disease that is caused by the pathogen Rhizoctonia solani. All turfgrass species are susceptible to its infection, but bentgrass (especially colonial bentgrass), fescue and perennial ryegrass are most at risk. In the transition zone, Mid-Atlantic, Midwest and Northeast, susceptible turfgrass can be exposed to brown patch under summer conditions with high humidity and nighttime temperatures above 65 F.

Brown patch symptoms will vary depending on grass species and mowing height. On wide-bladed turf species like tall fescue, leaf lesions develop with tan centers and dark brown margins. These leaves will die quickly, leaving a blighted area of turfgrass. On lower mowed turfgrass, the disease typically causes rings or patches of blighted turfgrass that will be highlighted with a brownish border.

Cultural practices

Generally, brown patch is more severe during extended periods of hot, humid weather (low and high temperatures above 70 F and 90 F, respectively). Poor soil drainage, lack of air movement, over-watering and excessive nitrogen also contributes to brown patch development.

The following cultural practices will help mitigate brown patch:

• Avoid night watering to reduce periods of leaf wetness
• Aerate high-traffic areas in the fall to increase soil drainage and reduce soil compaction
• Use moderate amounts of nitrogen fertilizers
• Remove morning dew to prevent extended leaf wetness

Preventive solutions

Combining cultural management techniques with preventive fungicide applications is the best strategy to manage this turf disease. R. solani can concentrate itself in the thatch and in areas of past infection, which is why it’s important to keep accurate records of disease history. Early curative fungicide applications will stop progression of the disease.

Ascernity^®, Heritage^® Action™, Briskway^®, Posterity XT, and Velista^® fungicides are excellent choices for both preventive and curative control of brown patch on greens tees and fairways. Used alone and in combination with each other they can offer excellent solutions for turf and provide the following features:

• Ascernity contains SOLATENOL^® technology, which is active on brown patch, anthracnose and host of other turf diseases.
  
• Heritage Action, Posterity XT, Posterity Forte and Briskway all contain the active ingredient, azoxystrobin, which delivers broad-spectrum control of brown patch as well as many major turf diseases.
• Save 11% with the Posterity XT + Ascernity Multipak
• Posterity XT provides up to 28 days of brown patch control, while Posterity Forte fungicide delivers strong dollar spot with added brown patch control for fairway applications.
• Briskway, Posterity Forte and Posterity XT also provide control of dollar spot.
• Velista contains the active ingredient penthiopyrad, which also provides broad-spectrum control of both brown patch and dollar spot.

Rutgers University, 2015

For more information about brown patch control, view our agronomic programs or download the GreenCast^® Turf App for both Apple^® and Android™ smartphones and tablets.

© 2024 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties and/or may have state-specific use requirements. Please check with your local extension service to ensure registration and proper use. Action™, Ascernity^®, Briskway^®, GreenCast^®, Heritage^®, Posterity^®, SOLATENOL^®, Velista^® and the Syngenta logo are trademarks of a Syngenta Group Company.