Turfgrass Disease Trends in California and the Western United

States

Naveen Hyder & Frank WongDepartment of Plant Pathology & Microbiology

University of California, Riverside

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

Objective 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?

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 2006-2009 (present)

Collecting a data point

Microscopic signs >>> incubate up to 24-48 hrs

Isolation from tissueLeaves, roots and crown on pathogen specific

media

Turf Management for Golf Courses 2001 J. Beard

Common turfgrass species used in California and the Western U.S.

Cool Season (C3 Photosynthesis)

Poa annuaPoa trivialisAgrostis stoloniferaFestuca

arundinaceaFestuca rubraLolium perenne

Warm Season (C4 Photosynthesis)

Cynodon spp. Pennisetum clandestinumPaspalum

vaginatumStenotaphrum secundatum

Geographic origin(based on # of samples received)

2006 2007 2008 2009

Arizona 7 2 1 13

California 389 (85%)

366 (80%)

235 (77%)

402 (79%)

Colorado 1 3 1 11

Hawaii 4 6 6 5

Idaho 3 1 6 7

Nevada 23 (5%) 40 (9%) 28 (9%) 25 (5%)

Oregon 7 14 11 9

Texas 2 1 0 3

Utah 1 3 3 2

Washington

20 (4%) 17 (4%) 12 (4%) 31 (6%)

n = 460 n = 457 n = 306 n = 512

Sources of samples(based on number of samples received)

2006 2007 2008 2009

Residential/ commercial landscape

8 7 15 15

Sports turf 11 11 7 18

Golf courses 438 (95%)

439(96%)

283(92%)

477 (93%)

Sod farms 3 - 1 2

n = 460 n = 457 n = 306 n = 512

Most common turfgrass hosts

Data based on n= 3,360 diagnosis

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%)

Brown Ring Patch (9%)

Summer Patch (8%)

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

AnthracnoseAlgae

Rapid BlightSummer Patch

Brown Ring Patch

0

2

4

6

8

10

12

14

16

18

2006 2007 2008 2009

Annual

blu

egra

ss/p

athog

en in

tera

ctio

ns

(%

)Most common diagnoses on Poa annua

(Annual bluegrass)

AnthracnoseAlgae

Rapid BlightSummer Patch

Brown Ring Patch

0

2

4

6

8

10

12

14

16

18

2006 2007 2008 2009

Annual

blu

egra

ss/p

athog

en in

tera

ctio

ns

(%

)Most common diagnoses on Poa annua

(Annual bluegrass)

Agrostis stolonifera (Creeping bentgrass) disease trendsTop 5 from 2006-20092006 (263) * 2007 (201) * 2008 (185) * 2009 (187) *

Algae (24%) Take-All Patch (23%)

Algae (10%) Anthracnose (18%)

Take-All Patch (21%)

Algae (10%) Take-All Patch (10%)

Take-All Patch (14%)

Fairy Ring (5%) Anthracnose (6%) Anthracnose (6%) Algae (11%)

Anthracnose (5%) Fairy Ring (4%) Pythium Blight (5%)

Fairy Ring (6%)

Pythium Blight (3%)

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

Lolium perenne (Ryegrass) disease trendsTop 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%)

Brown Patch (15%)

Curvularia Blight (14%)

Bipolaris Leaf Spot (15%)

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

Cynodon spp. (bermudagrass) disease trendsTop 3 from 2006 - 20092006 (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

Pennisetum clandestinum (kikuyugrass)

disease trendsTop 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

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

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

Future research scopeUse 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

Acknowledgements

GCSAA Environmental Institute of Golf

California State GCSAs

Syngenta Professional Products

Bayer Environmental Sciences