Brown Patch

Subscribe to our free E-Newsletter, "Agri-News" (formerly RTW This Week)Agri-News
This Week

Rhizoctonia solani

Disease description
A "smoke-ring" of greyish-black myceiium from 1.5 to 4 cm wide develops around an active patch. Attacked grass leaves show dark-bordered lesions, become water-soaked and blackened, collapse, then dry up and become light brown with scierotia at plant bases. Patches 2 cm to 1 m in diameter may occur in short mown turf. It may progress very rapidly. Mainly in parts of eastern Canada and southern B.C., although a lower temperature form of the disease has been found in the Prairies.

Predisposing factors
  • all grasses are affected, but some Agrostis cultivars are very susceptible
  • hot, very humid daytime weather conditions with night temperatures about 18 degrees C
  • unbalanced nitrogen applications leading to development of lush rapid growth
  • frequent mowing renders fine turf more susceptible, as the fungus gains entry through wounds
Cultural control
Avoid unbalanced or excessive nitrogen applications particularly where there is a history of the disease. Reduce frequency of mowing. Reduce irrigation, especially late in the day during danger periods.

For information about other diseases that affect turf grasses, go to Major Diseases of Turf Grasses in Western Canada
Share via AddThis.com
Share via AddThis.com
For more information about the content of this document, contact Shelley Barkley.
This information published to the web on November 20, 2001.
Last Reviewed/Revised on November 19, 2018.