1. The 2006 California Disease Round Up Frank P. Wong Cooperative Extension Specialist University of California GCSASC/SCGA/USGA Green Section Meeting Tustin Ranch Golf Club January 8, 2007

2. 2006 California Disease Overview 2006 was a busy year for the lab  > 450 diagnostic samples  1024 diagnoses  Wet, cool spring  Hot summer Turfgrass most affected  Annual Bluegrass (361)  Creeping Bentgrass (220)  Perennial Ryegrass (166)  Bermuda + Kikuyugrass (92)

3. 2006 California Disease Overview Most common diseases  Cyanobacteria/algae (158)  ETRI/Root Diseases (181) Summer Patch Take All Spring Dead Spot Decline  Heat Stress (82)  Anthracnose (48)  Rapid Blight (39)  Waitea/Brown Ring Patch (38)

6. 2006 Temperature - Riverside

7. 77 F soil temp is the upper limit for cool season root growth

8. 2006 Rainfall - Riverside

9. Annual bluegrass diseases

10. Creeping bentgrass diseases

11. Perennial Ryegrass Diseases

12. Warm Season Grass Diseases

13. 2006 Abiotic Problems

14. Above normal rainfall in northern California Photo courtesy of PACE Consulting

15. Severe Pink Snow Mold Development below 65F Photo courtesy of PACE Consulting

16. Fungicide Resistance for M. nivale (Pink Snow Mold) Several locations reported reduced control with 26GT or QoI fungicides Dicarboximide resistance (26 GT)  Reported in 1986 in Washington (Chastagner)  Resistance = tolerance QoI resistance (Compass, Heritage, Insignia)  Not reported in U.S. as of 2005  Resistance = immunity

17. Sensitivity of M. nivale isolates to iprodione (26GT) and azoxystrobin (Heritage) 50 isolates from 4 locations

18. Fungicide Resistance for M. nivale (Pink Snow Mold) Dicarboximide resistance present in CA populations  22% of isolates (4/4 locations)  No new news Minimize curative applications Preventive, high rate applications should still be effective Tank mixes with other systemics should be effective  SI-fungicides  Medallion?

19. Fungicide Resistance for M. nivale (Pink Snow Mold) QoI resistance present in CA populations  30% of isolates (2/4 locations)  1 st report in US  Need to confirm molecular mechanisms No more curative applications Be careful with pre-mix products containing QoI-fungicides  Tartan (Compass + Bayleton)  Headway (Heritage + Banner MAXX)

20. Root diseases on putting greens Over 150 samples for take all on bent, summer patch on poa or heat stress on both

21. Waitea (Brown Ring) Patch on annual bluegrass, Palos Verdes, CA

22. Brown Ring Patch Appears that the majority of “Yellow Patch” in the west is actually “Brown Ring Patch” 60 to 85 F range, 75 to 80 F appears optimal (May-June) Fungicides  Excellent: Prostar, Heritage, Medallion Endorse  Good: Banner, Insignia, Compass, Daconil, 26GT Water in fungicides, apply preventively

23. Cyanobacteria/Algae on Annual Bluegrass

25. Photo courtesy of PACE Consulting

26. Cyanobacteria & Algae Common on damaged greens Can cause “Yellow Spot”  Nov. 2006 GCM article by Tredway, Stowell and Gelernter Control by  Reducing organic fertilizer use  Increase shade and air movement  Increased water infiltration  Daconil Ultrex applications

27. Summer Decline/Take All on a mixed bentgrass/annual bluegrass green

28. Summer Decline/Heat Stress on a bentgrass green

29. Summer Patch on an annual bluegrass green Photo courtesy of PACE Consulting

30. Take All Patch on Creeping Bentgrass Wet winter allowed for more pathogen activity on roots Under heat stress, many damaged root systems collapsed Factors associated with Take All  High organic matter and thatch  Skipped fall aerification  No preventive fungicide applications in the fall Banner MAXX 2-4 fl oz, 2 to 3 application in the fall at soil temps below 65 F Manganese above 35 ppm in soil

31. Summer Patch on Poa annua Heat stress on shallow root systems increased the impact of any pathogen damage Factors associated with high damage similar for TAP  High organic matter and thatch  Skipped fall/spring aerification 14-21 day Heritage/Insignia applications were more effective than 28 day 65 F is still the magic number to start fungicide applications  Banner MAXX  Heritage or Insignia

32. Turfgrass Anthracnose C. cereale

33. Cultural Inputs for Anthracnose Management (Rutgers University) Greatest cultural impacts  adequate N - 18-36% disease with 1/8# urea every 2 wks  moderate cutting height + 10-40% at 0.110-in vs 0.142-in  growth regulator use - 10% with regular Primo MAXX use  adequate irrigation and cooling

34. Thoughts on Anthracnose Management QoIs  Resistance still a problem  Found at 3 sites in 2006 Benzimidazoles  Not as bad as QoI resistance  Found at 2 sites in 2006  Still viable if not previously overused

35. Thoughts on Anthracnose Management SI-fungicides  Banner MAXX and Lynx are the top choices  No PGR effects observed in trials  Be careful if temps are above 90F Contacts  “Paint it white – sleep at night”  Higher fall basal rot observed at some sites where contacts were used 100%

36. Thoughts on Anthracnose Management Signature Tank Mixes  Still look good in 3 rd year of testing  Mechanism unknown  Tank mix with systemics to reduce fall basal rot Biologicals (Bacillus spp.)  Humabalance, Rhapsody, Ecogard  Variable results  Not as strong as synthetics but can be effective when integrated in control programs  7 day applications appeared more effective than 14 day applications

37. Thoughts on Anthracnose Management Others  Medallion still looks good 0.5 oz or tank mixed  Endorse Good performance Stronger when tank mixed with a contact

38. Grey Leaf Spot (Pyricularia grisea)

39. 2006 Distribution of Gray Leaf Spot

40. GLS on kikuyugrass was seen commonly in southern California

41. Figure 1C F129 L tolerant isolates found at 6 locations G143A at three locations No resistance to benzimidazoles Resistance status R R R R R R R K K

42. Sensitive Resistant 0 ppm 1 ppm AZX 100 ppm AZX

43. 2006 Gray Leaf Spot Kikuyugrass incidence common in 2006  Appears that some isolates can infect both ryegrass and kikuyugrass Fungicides  QoIs Be aware of resistance  SI-contact tank mixes  Clearys 3336 + Contacts Be aware of new label restrictions  Fairway priced pre-packs may be a option Tartan (Bayleton + Compass) Headway (Banner MAXX + Heritage) Instrata (Banner MAXX + Medallion + Daconil) Concert (Banner EC + Daconil)

44. Rapid Blight

45. Soil Salinity for Annual Bluegrass Greens Samples 2004 273 RB (-), 84 RB (+)

46. Soil Salinity and Rapid Blight Negative samples  mean: 1.69 dS/m  median: 1.61 dS/m  range: 1.07 to 6.2 dS/m Positive samples  mean: 3.13 dS/m  median: 2.96 dS/m  range: 1.07 to 9.1 dS/m

47. 2006 Rapid Blight Sporadic all year long Dominant in the fall this year due to lack of rainfall Still triggered by salt (sodium)  Regular monitoring with TDS-meter and leaching are your best defense  Calcium treatment to replace sodium in soil appears to be a good strategy Fungicides  Insignia or Compass + mancozeb (Fore)  Recommended to always tank mix with Fore for resistance management

48. Questions???? Contact Info frank.wong@ucr.edu plantpathology.ucr.edu