PACE Turf - Turfgrass Information Center

Diseases

Using virtual irrigation to forecast disease

Poster presentation at the 2008 American Phytopathological Society meetings, July 26 - 30, Minneapolis, MN.

Authors: Larry Stowell and Wendy Gelernter (PACE Turfgrass Research Institute) and Frank Wong and Chi-Men Chen, University of California Riverside

Click here to view the poster (130 KB)

Summary: Recent research suggests that soil moisture impacts the severity of turf diseases such as anthracnose caused by Colletotrichum cereale, Pythium root dysfunction caused by Pythium volutum, gray leaf spot (GLS) caused by Magnaporthe grisea and brown ring patch (BRP) caused by Waitea circinata var. circinata. The virtual irrigation audit, a simple computer model that predicts the size and location of both wet and dry areas on golf course turf, was designed to provide diagnosticians and turf managers with a precision turfgrass management tool for disease and soil moisture management. In this study, the virtual audit was successfully used to describe the occurrence of GLS and BRP on golf course turf.

Brown ring patch project receives GCSAA funding

The project, "Management and Biology of Brown Ring Patch on Annual Bluegrass Greens", led by researchers Frank Wong, Ph.D., University of California, and Larry Stowell, Ph.D., PACE Turf, has received two years of funding from the Golf Course Superintendents Association of America. A total of $62,000 will be provided to the project over a 2-year period. Contributing to this funding were the national GCSAA office, as well as:

  • the GCSA of Central California
  • the GCSA of Northern California
  • the GCSA of Southern California
  • Hi-Lo Desert GCSA
  • San Diego GCSA
  • Sierra Nevada GCSA
  • California State Chapter GCSA

Brown ring patch, caused by the fungus Waitea circinata var. circinata is causing increasing damage on Poa annua greens. The full text of the proposal can be reviewed in this document.

Cyanobacteria (A.K.A. blue-green algae): WANTED for causing serious damage to turf

There are three widely shared misconceptions about the small, photosynthetic microbes that produce dark crusts and slime layers on putting green soils and foliage. The first is that all of these organisms are algae, when in fact many of them are cyanobacteria - microscopic organisms that are very different from true algae. The second misconception is that these organisms don't cause direct damage to turf, but are instead only secondary problems that result after turf has been stressed by disease, too much shade, poor drainage, or other factors. But in our diagnostic work we consistently find the opposite to be true. That is, cyanobacteria are frequently the direct cause of turf damage - resulting in mottled, yellowed and thinning turf on many cool season and warm season greens throughout the U.S. Thirdly, it is generally believed that algae or cyanobacteria are only problems in shady, wet areas. But we see many problems from sunny and relatively dry locations as well. From the standpoint of control, preliminary results indicate that although eradication is an unrealistic goal, several weekly treatments with chlorothalonil (Concorde, Daconil, Echo, Manicure, Thalonil) usually improves turfgrass quality by reducing cyanobacteria populations.

Full print version: PACE Insights 2000 Vol. 6 No. 8

Page 3 of 8 pages  < 1 2 3 4 5 >  Last ›

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