1. Turfgrass Disease Trends in California and the Western United States
Naveen Hyder & Frank Wong Department of Plant Pathology & Microbiology University of California, Riverside

2. Background information
California has the largest turf and landscape industry in the US (approx. 15 billion)
Approx. 950 golf courses in the state of California – 2nd in the US
Not much information available due to lack of turfgrass pathology program since the1990s
1997 survey green industry worth 6 billion 15 billion/golf 7 billion
First attempt to quantify data

3. Objective What are the major disease problems?
To assess turfgrass disease trends in California and the Western United States based on diagnostic laboratory data
What are the major disease problems?
What are the major hosts?
What are the disease trends over the last four years?
Where should research efforts be focused?

4. Materials and methods
A sample = 1 cup cutter size plug of plants and soil
For this study 1 data point = one pathogen/plant interaction
Data based on diagnostic samples received
Samples are not evenly distributed throughout the Western United States
Multiple samples from the same location
Data collected from (present)

5. Collecting a data point
Microscopic signs >>> incubate up to hrs
Isolation from tissue
Leaves, roots and crown on pathogen specific media
Samples delivered overnight

6. Turf Management for Golf Courses 2001 J. Beard
Large area encompassing several climate zones
Turf Management for Golf Courses 2001 J. Beard

7. Common turfgrass species used in California and the Western U.S.
Cool Season
(C3 Photosynthesis)
Poa annua
Poa trivialis
Agrostis stolonifera
Festuca arundinacea
Festuca rubra
Lolium perenne
Warm Season
(C4 Photosynthesis)
Cynodon spp.
Pennisetum
clandestinum
Paspalum vaginatum
Stenotaphrum
secundatum
65 to 75°F Summer dormant to 95°F Winter dormant bermudagrass – common and hybrid

8. Geographic origin (based on # of samples received)
2006
2007
2008
2009
Arizona 7 2 1 13
California
(85%)
(80%)
(77%)
(79%)
Colorado 3 11
Hawaii 4 6 5
Idaho
Nevada
23 (5%)
40 (9%)
28 (9%)
25 (5%)
Oregon 14 9
Texas
Utah
Washington
20 (4%)
17 (4%)
12 (4%)
31 (6%)
n = 460
n = 457
n = 306
n = 512

9. Sources of samples (based on number of samples received)
2006
2007
2008
2009
Residential/ commercial landscape 8 7 15
Sports turf 11 18
Golf courses
438 (95%)
439
(96%)
283
(92%)
477
(93%)
Sod farms 3 - 1 2
n = 460
n = 457
n = 306
n = 512

10. Most common turfgrass hosts
Data based on n= 3,360 diagnosis

11. Poa annua (Annual bluegrass) diseases trends Top 5 from 2006 to 2009
2006 (442) *
2007 (425) *
2008 (471) *
2009 (358) *
Algae (17%)
Rapid Blight (11%)
Anthracnose (14% )
Anthracnose (18%)
Summer Patch (15%)
Anthracnose (11%)
Rapid Blight (13%)
Rapid Blight (8%)
Rapid Blight (9%)
Summer Patch (9%)
Algae (12%)
Algae (8%)
Brown Ring Patch (9%)
Summer Patch (8%)
Anthracnose (8%)
Algae (6%)
Brown Ring Patch (5%)
Michrodochium Patch (6%)
* Total annual bluegrass samples processed
Algae (Cyanobacteria) = Oscillatoria spp.
Anthracnose = Colletotrichum cereale
Brown Ring Patch = Waitea circinata var. circinata
Rapid Blight = Labyrinthula terrestris
Summer Patch = Magnaporthe poae
Michrodochium Patch = Michrodochium nivale

14. Agrostis stolonifera (Creeping bentgrass) disease trends Top 5 from 2006-2009
2006 (263) *
2007 (201) *
2008 (185) *
2009 (187) *
Algae (24%)
Take-All Patch (23%)
Algae (10%)
Anthracnose (18%)
Take-All Patch (21%)
Take-All Patch (10%)
Take-All Patch (14%)
Fairy Ring (5%)
Anthracnose (6%)
Algae (11%)
Anthracnose (5%)
Fairy Ring (4%)
Pythium Blight (5%)
Fairy Ring (6%)
Pythium Blight (3%)
Rhizoctonia Brown Patch (4%)
Rhizoctonia Brown Patch (5%)
* Total creeping bentgrass samples processed
Algae (Cynobacteria) = Oscillatoria spp.
Anthracnose = Colletotrichum cereale
Fairy Ring = Various Basidiomycete spp.
Pythium Blight = Pythium spp.
Rhizoctonia Brown Patch = Rhizoctonia solani
Take-All Patch = Gaeumannomyces graminis var. avenae

16. Lolium perenne (Ryegrass) disease trends Top 3 from 2006 - 2009
2006 (173)*
2007 (106)*
2008 (61)*
2009 (67)*
Bipolaris Leaf Spot (15%)
Brown Patch (21%)
Brown Patch (18%)
Anthracnose (39%)
Brown Patch (15%)
Curvularia Blight (17%)
Anthracnose (16%)
Curvularia Blight (14%)
Summer Patch (7%)
Bipolaris Leaf Spot (9%)
*Total ryegrass samples processed
Anthracnose = Colletotrichum cereale
Bipolaris Leaf Spot = Bipolaris spp.
Brown Patch = Rhizoctonia solani
Curvularia Blight = Curvularia spp.
Summer Patch = Magnaporthe poae

17. Cynodon spp. (bermudagrass) disease trends Top 3 from 2006 - 2009
2006 (65)*
2007 (21)*
2008 (45)*
2009 (79)*
Spring Dead Spot (23%)
Rhizoctonia Large Patch (38%)
Bermudagrass Decline (29%)
Bermudagrass Decline (35%)
Bipolaris Leaf Spot (22%)
Spring Dead Spot (28%)
Spring Dead Spot (18%)
Spring Dead Spot (10%)
Bermudagrass Decline (17%)
Bipolaris Leaf Spot (14%)
Bipolaris Leaf Spot (10%)
* Total Bermudagrass samples processed
Spring Dead Spot = Ophiosphaerella narmari / O. korrae
Bipolaris Leaf Spot = Bipolaris spp.
Bermudagrass Decline = Gaeumannomyces graminis var. graminis
Rhizoctonia Large Patch = Rhizoctonia solani

18. Pennisetum clandestinum (kikuyugrass) disease trends Top 3 from 2006 - 2009
2006 (28)*
2007 (18)*
2008 (23)*
2009 (14)*
Gray Leaf Spot (38%)
Kikuyugrass Decline (38%)
Kikuyugrass Decline (44%)
Rhizoctonia Large Patch (43%)
Kikuyugrass Decline (21%)
Gray Leaf Spot (16%)
Rhizoctonia Large Patch (22%)
Kikuyugrass Decline (36%)
Rhizoctonia Large Patch (18%)
Rhizoctonia Large Patch (16%)
Gray Leaf Spot (13%)
*Total Kikuyugrass samples processed
Gray Leaf Spot = Pyricularia grisea
Kikuyugrass Decline = Gaeumannomyces graminis var. graminis
Rhizoctonia Large Patch = Rhizoctonia solani AG 2-2

19. Summary Total # of samples received (2006-2009) = 3,360
94 % of the samples received are from golf courses
90% of these samples from golf course greens
Cool season grasses comprise 85% of the samples
50% of these samples are annual bluegrass
# 1 problem on annual bluegrass is Anthracnose

20. Conclusions
First effort to summarize data pertaining to turfgrass diseases in the Western United States
California has a unique turfgrass disease profile because of diversity of climate zones within the state
Top research priority should be cool season turf management esp. diseases of annual bluegrass
Find replacement for poa or find better ways of managing

21. Future research scope Use the data base to:
Compare and contrast information with other regions
Correlate disease trends with climatic variations
Correlate disease trends with agronomic practices specific to California

22. Acknowledgements GCSAA Environmental Institute of Golf
California State GCSAs
Syngenta Professional Products
Bayer Environmental Sciences