UC IPM Online UC ANR home page UC IPM home page

UC IPM Home

SKIP navigation

 

How to Manage Pests

The UC Guide to Healthy Lawns

Leaf spot — Bipolaris spp.

Leaf spot disease
Photo by Ali Harivandi

Click on image to enlarge.

Hosts

Annual bluegrass (a common weed in turf), Kentucky bluegrass

Symptoms

Infected leaves, sheaths and stems have circular to elongated brownish spots with brown centers and dark brown or purple borders. Crowns and roots have a dark brown rot. Symptoms may occur throughout the lawn rather than in clumped areas. Plants may die in hot, windy weather, leaving thinned areas throughout the turf.

Conditions favoring disease

Warm temperatures (70° to 90°F) and high humidity favor the development of leaf spot. Weakened turf may be the result of poor cultural practices. Mowing too short and applying high amounts of nitrogen contribute to the development of the disease.

Prevention and management

Reduce shade and improve soil aeration and water drainage. Follow the recommended irrigation requirements for your turf species and avoid excess nitrogen fertilizer. Maintain as high a mowing cut as possible. Fungicides are available but usually are not warranted for the home lawn.

For more information on lawn diseases, refer to:
Pest Notes: Lawn Diseases: Prevention and Management


Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2016 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   /TOOLS/TURF/PESTS/dislfspt.html revised: June 21, 2016. Contact webmaster.