Are Your Customers At Risk for Summer Brown Patch?
Posted By Ben Pease, PhD, Agronomist on May 30, 2023
Disease prevention is an important component of client satisfaction during any growing season. Starting a program for disease prevention, however, can seem a bit daunting if you're not familiar with how pathogens work.
To begin, you have to understand the elements that are necessary for disease to occur. For disease to occur, you must first have a susceptible plant host. In this case, turfgrass. Next, you must have the environmental conditions that favor disease development. Finally, if the pathogen is present, you have all three elements of the disease triangle. This creates the conditions favoring development. Removing just one of these three elements can eliminate the possibility for the disease to occur.
One of the most prevalent summer turfgrass diseases that impacts cool-season tall fescue lawns is Rhizoctonia solani, more commonly known as brown patch. Here is a quick checklist of items that can help you determine if the lawns you service may be susceptible to damage from brown patch.
1. Identify The Turfgrass
Brown patch pathogen favors tall fescue as a host, but can also be seen on other cool-season turf species such as perennial ryegrass and creeping bentgrass.
2. Monitor and Identify Environmental Conditions
Brown patch is considered a hot-weather disease, with development typically occurring during the summer months. Nighttime temperatures above 80 degrees coupled with leaf wetness periods of 10 hours or greater are ideal for brown patch development. To prevent extended leaf wetness periods, irrigation should only be run at night, preferably between midnight and 5am.
3. Identify Pathogen Symptoms and Signs
The pictures below illustrate the stages of brown patch development, from the fungus causing the disease to an infected lawn.
In the above picture, mycelium (white thread-like structure) is the sign of the fungus that causes brown patch.
Pictured above is a turfgrass leaf blade with a brown patch lesion present. The irregular shape of the patch, along with the tan margin, help in disease identification.
Pictured above is a lawn infected with brown patch. The disease typically shows up as a circular patch, but can also have less defined margins, as seen in the front of the photograph.
How to Prevent Brown Patch
A preventative program, as opposed to a curative program, is always more effective and economic in keeping brown patch at bay. Whether you take the preventative approach or you are forced into a curative scenario, you’ll need the right product for the job.
Lawn care professionals across the country trust Prophesy® DG and Signify™ DG granular fungicides to provide broad-spectrum, systemic suppression and protection against brown patch, dollar spot, pythium, anthracnose, and other summer diseases.
Featuring Dispersing Granule (DG) Technology and providing up to four weeks* of residual control with strong economics per 1,000 square feet, these products represent ideal pillars for any summer disease program.
Features 0.72% propiconazole. Provides broad-spectrum control of more than 20 common lawn diseases including brown patch and zoysia patch.
Features 0.31% Azoxystrobin + 0.75% Propiconazole. Provides broad-spectrum control of more than 20 common lawn diseases including brown patch, zoysia patch, and pythium. Avoids the need to create a special tank mix; any applicator can apply as they would granular fertilizer.
If disease is already a problem, consider using the maximum application rate with the shortest application interval. By contrast, if you do not have disease present, but you're looking to start a preventative program, use the lower application rate with similar application intervals.
Ben Pease is the Agronomist for The Andersons Turf & Specialty business, responsible for research, service, and technical support. Ben received both his bachelor's and master's degrees from the University of Wisconsin, and earned his doctorate degree from Iowa State University. Ben has also served as the Assistant Superintendent for Cherokee Country Club (Madison, WI) and Whistling Straits Golf Courses (Sheboygan, WI). To contact Ben, click here.
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