Potassium Nitrate Can Reduce Anthracnose Severity of Annual Bluegrass Turf

anthrancnose close up

Photograph Caption:  Early results of a USGA-funded research project at Rutgers University strongly suggest that a weekly application of potassium nitrate during the growing season reduces anthracnose disease severity. Anthracnose first appears on annual bluegrass as 1/4 to 1/2-inch diameter spots of yellow to orange-brown turf. In a short time, the small spots can progress into large, irregularly shaped areas on infected putting greens, tees, or fairways. Infection often occurs first on older leaves of plants, causing yellow leaf lesions. 

Anthracnose is a common fungal disease of annual bluegrass putting greens in the United States. Previous USGA-funded research at Rutgers University found that increasing ammonium nitrate rates up to 0.2 lbs. of nitrogen per 1000 ft2 per week during the growing season reduced anthracnose severity compared to lower nitrogen rates. A new USGA study at Rutgers University looked at the applied nitrogen source effect on the severity of anthracnose outbreaks. The five soluble-nitrogen products tested include ammonium sulfate, ammonium nitrate, urea, calcium nitrate, and potassium nitrate applied at 0.1 lbs. of nitrogen per 1000 ft2 every 7 or 14 days. This three-year field trial was initiated spring 2010 in North Brunswick, N.J. on an annual bluegrass putting green maintained at a 0.125 inch height of cut. In general, potassium nitrate treatments had the lowest anthracnose severity; whereas, ammonium sulfate treatments had the greatest anthracnose severity. Application frequency also had a significant impact on disease severity throughout the study. Weekly applications of soluble nitrogen consistently reduced disease severity compared to biweekly applications. The biweekly applications of all soluble nitrogen sources tested did not provide a sufficient amount of nitrogen to reduce anthracnose severity. The early results strongly suggest that weekly applications of potassium nitrate were required to significantly reduce anthracnose severity.


Further information can be found at:

Best Management Practices for Anthracnose Disease on Annual Bluegrass Putting Greens

Cultural Management of Anthracnose Disease on Annual Bluegrass

Biology and Pathology of Turfgrass Anthracnose

Anthracnose of Turfgrass

Best Management Practices for Anthracnose on Annual Bluegrass Turf


Partner Links
AmEx image
AmEx image
AmEx image
AmEx image

The USGA and Chevron have committed to using the game of golf to encourage students in science, technology, engineering and math (STEM) disciplines. This commitment has led to the creation of extensive golf-focused STEM teaching tools, and has resulted in charitable contributions to support golf-related programs through Eagles for Education™

At U.S. Open Championships the Chevron STEM ZONE™ is an interactive experience highlighting the science and math behind the game of golf through a variety of hands-on exhibits and experiments.

The partnership has also produced educational materials such as the Science of Golf video series and a nationally-distributed newspaper insert which are provided to teachers as tools to enhance existing curriculum in schools. These lessons teach the science behind the USGA’s equipment testing, handicapping, and agronomy efforts.

For more interactive experiences featuring golf-focused STEM lessons, visit the partnership homepage.

Chevron image

Rolex has been a longtime supporter of the USGA and salutes the sportsmanship and great traditions unique to the game. This support includes the Rules of Golf where Rolex has partnered with the USGA to ensure golfers understand and appreciate the game.

As the official timekeeper of the USGA and its championships, they also provide clocks throughout host sites for spectator convenience.

For more information on Rolex and their celebration of the game, visit the Rolex and Golf homepage.

Rolex image

IBM has partnered with the USGA to bring the same technology, expertise, and innovation it provides to businesses all over the world to the USGA and golf's national championship.

IBM provides the information technology to develop and host the U.S. Open’s official website, www.usopen.com, as well as the mobile apps and scoring systems for the three U.S. Open championships. These real-time technology solutions provide an enhanced experience for fans following the championship onsite and online.

For more information on IBM and the technology that powers the U.S. Open and businesses worldwide, visit http://www.usopen.com/IBM

AmEx image

Lexus is committed to partnering with the USGA to deliver a best-in-class experience for the world’s best golfers by providing a fleet of courtesy luxury vehicles for all USGA Championships.

At each U.S. Open, Women’s Open and Senior Open, Lexus provides spectators with access to unique experiences ranging from the opportunity to have a picture taken with both the U.S. Open and U.S. Women’s Open trophies to autograph signings with legendary Lexus Golf Ambassadors in the Lexus Performance Drive Pavilion.

For more information on Lexus, visit http://www.lexus.com/

AmEx image
American Express

Together, American Express and the USGA have been providing world-class service to golf fans since 2006. By creating interactive U.S. Open experiences both onsite and online, American Express enhances the USGA’s effort to make the game more accessible and enjoyable for fans.

For more information on American Express visit www.americanexpress.com/entertainment

AmEx image