Georgia Golf Course Superintendents Association Annual Bentgrass Forum August 29, 2011

1. Fungi, Bacteria and Nematodes
Does Bentgrass Stand a Chance?
Lane Tredway
Associate Professor and Extension Specialist
Department of Plant Pathology
North Carolina State University

2. Is bentgrass an endagered
species in the Southeast?

4. Is it getting hotter?
1980s 1990s 2000s
90
Mean High Temperature (F)
80
70
60
50
40
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Raleigh/Durham International
Airport

5. Heat imposed severe stress on creeping bentgrass
greens in 2010....
15
departure from normal HIGH temperature
departure from normal LOW temperature
10
Departure from Normal (F)
5
0
-5
-10
-15
May June July August Sept Oct

6. ...and again in 2011.
15
departure from normal HIGH temperature
departure from normal LOW temperature
10
Departure from Normal (F)
5
0
-5
-10
-15
May June July August

7. Was 2010 Wet or Dry? Both!
7
Cumulative Rainfall (in.)
5.25
3.5
1.75
0
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov

8. Rainfall was more consistent over 2011
2
Cumulative Rainfall (in.)
1.5
1
0.5
0
May June July Aug Sept

9. Everyone is feeling the economic downturn.
Do you have more or less
discretionary income today?

14. Save the bentgrass!

15. We’re doing our part at NC State.

16. Key Survival Practices for Creeping Bentgrass
in Subtropical Environments
What does grass need to be healthy?
light
air
food
water

17. What is the limiting factor to turf health?

18. Fans are critical where air movement is restricted.

19. Fans do not correct
for shade and tree
root competition

28. Pythium root rot was the most common and severe
creeping bentgrass disease in 2010 and 2011.

29. Pythium root and crown rot
• putting green disease
• many Pythium species (20+)
can cause root and crown rot
• induced by wet soil conditions
• annual bluegrass and creeping
bentgrass most susceptible
• bermudagrass and seashore
paspalum can also be affected

30. Pythium root rot often appears in
irregular patterns

31. Symptoms can be ‘patchy’ during
periods of very wet weather

32. Spread in drainage patterns is
common.

34. Photo by Bruce Martin

35. A lab diagnosis is necessary to
confirm Pythium root rot.

36. Pythium root rot is
induced by wet soils

37. Even new, well-drained greens can
be affected during wet weather

38. Layering
can trigger
root rot
problems

39. Pythium Root Rot: Chemical Control
Few fungicides are specifically labeled for Pythium root rot, and little
is known about their relative efficacy.
FRAC Code Chemical Class Common Names Products
11 QoI azoxystrobin, fluoxastrobin Heritage, Disarm
aromatic
14 ethazole Terrazole
hydrocarbons
21 QiI cyazofamid Segway
28 carbamates propamocarb Banol, Stellar
33 phosphonates fosetyl-Al, phosphorous acid Signature, Alude, Resyst
43 benzamides fluopicolide Stellar

40. Disease Management Utility on TurfFiles
turfdiseasemanagement.ncsu.edu

41. Disease Management Utility on TurfFiles
turfdiseasemanagement.ncsu.edu

42. Pythium Root Rot: Chemical Control

43. Pythium Root Rot: Chemical Control
Preventative

44. Pythium Root Rot: Chemical Control
Preventative
• applications of cyazofamid, ethazole, mefanoxam,
or propamocarb during periods of wet weather

45. Pythium Root Rot: Chemical Control
Preventative
• applications of cyazofamid, ethazole, mefanoxam,
or propamocarb during periods of wet weather
• watered-in with 1/8” of irrigation for best results

46. Pythium Root Rot: Chemical Control
Preventative
• applications of cyazofamid, ethazole, mefanoxam,
or propamocarb during periods of wet weather
• watered-in with 1/8” of irrigation for best results
Curative

47. Pythium Root Rot: Chemical Control
Preventative
• applications of cyazofamid, ethazole, mefanoxam,
or propamocarb during periods of wet weather
• watered-in with 1/8” of irrigation for best results
Curative
• ethazole (Koban, Terrazole), followed 2 to 3 days
later by a systemic product (cyazofamid,
mefanoxam, propamocarb)

48. Pythium Root Rot: Chemical Control
Preventative
• applications of cyazofamid, ethazole, mefanoxam,
or propamocarb during periods of wet weather
• watered-in with 1/8” of irrigation for best results
Curative
• ethazole (Koban, Terrazole), followed 2 to 3 days
later by a systemic product (cyazofamid,
mefanoxam, propamocarb)
• watered-in with 1/8” of irrigation for best results

49. Pythium root rot is driven by soil moisture.

51. “It can’t be a disease because I’m on Program 13!”

52. Spray programs are not uncommon in agriculture.
flickr:TaminaMiller

53. Every golf course is different.
Climate, microclimate,
expectations, and
management styles vary.

54. Art and Science

55. Where’s the art in this?

56. Program ’11
How to develop and implement a fungicide program.

57. Program ’11
How to develop and implement a fungicide program.
1. develop list of diseases based on location, cultivar, soil
type, and history

58. Program ’11
How to develop and implement a fungicide program.
1. develop list of diseases based on location, cultivar, soil
type, and history
2. use historical weather data to determine when each
disease is ‘normally’ active

59. Program ’11
How to develop and implement a fungicide program.
1. develop list of diseases based on location, cultivar, soil
type, and history
2. use historical weather data to determine when each
disease is ‘normally’ active
3. select product(s) that will control the disease(s) that are
expected to be active each week

60. Program ’11
How to develop and implement a fungicide program.
1. develop list of diseases based on location, cultivar, soil
type, and history
2. use historical weather data to determine when each
disease is ‘normally’ active
3. select product(s) that will control the disease(s) that are
expected to be active each week
4. select rates, intervals, and application method

61. Program ’11
How to develop and implement a fungicide program.
1. develop list of diseases based on location, cultivar, soil
type, and history
2. use historical weather data to determine when each
disease is ‘normally’ active
3. select product(s) that will control the disease(s) that are
expected to be active each week
4. select rates, intervals, and application method
5. adjust as needed based on actual weather conditions

63. PRD Segway Honor Signature + Banol
fairy ring Bayleton Torque
dollar spot Honor Torque 26GT Disarm C Honor
algae Daconil Ult Disarm C Fore
brown patch 26GT Disarm C Honor
PRR Segway Signature + Banol Terrazole Subdue
Segway Bayleton Honor Torque Signature 26GT Terrazole Disarm C Subdue Honor
0.9 fl oz 1 fl oz 1.1 oz 0.6 fl oz 4 oz 4 fl oz 4 fl oz 5 fl oz 1 fl oz 1.1 fl oz
water-in water-in water-in water-in foliar foliar water-in foliar water-in foliar
Banol Daconil Ult Fore
2 fl oz 3.2 fl oz 6 oz
foliar foliar foliar

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68. Bacterial
Fright

69. History of Bacterial Wilt

70. History of Bacterial Wilt
• severe epidemic in Midwestern US on ‘Toronto’ creeping bentgrass in
1970’s caused by Xanthomonas transluscens

71. History of Bacterial Wilt
• severe epidemic in Midwestern US on ‘Toronto’ creeping bentgrass in
1970’s caused by Xanthomonas transluscens
• X. transluscens continues to be an occasional problem on Poa annua
greens in the northern US

72. History of Bacterial Wilt
• severe epidemic in Midwestern US on ‘Toronto’ creeping bentgrass in
1970’s caused by Xanthomonas transluscens
• X. transluscens continues to be an occasional problem on Poa annua
greens in the northern US
• efforts to develop this into a bioherbicide failed due to lack of efficacy
in absence of severe stress

73. History of Bacterial Wilt
• severe epidemic in Midwestern US on ‘Toronto’ creeping bentgrass in
1970’s caused by Xanthomonas transluscens
• X. transluscens continues to be an occasional problem on Poa annua
greens in the northern US
• efforts to develop this into a bioherbicide failed due to lack of efficacy
in absence of severe stress
• 2009 - report of a bacterial disease of creeping bentgrass caused by
Acidovorax spp. in Charlotte, NC

74. Bacterial Fright Timeline

75. Bacterial Fright Timeline
June 2009 - samples from Quail Hollow Country Club submitted to
Michigan State University for disease diagnosis

76. Bacterial Fright Timeline
June 2009 - samples from Quail Hollow Country Club submitted to
Michigan State University for disease diagnosis
October 1, 2009 - Michigan State reported to Quail Hollow that the
problem was a bacterial disease caused by a species of Acidovorax

77. Bacterial Fright Timeline
June 2009 - samples from Quail Hollow Country Club submitted to
Michigan State University for disease diagnosis
October 1, 2009 - Michigan State reported to Quail Hollow that the
problem was a bacterial disease caused by a species of Acidovorax
October 2, 2009 - attempted to contact Dr. Vargas for information

78. Bacterial Fright Timeline
June 2009 - samples from Quail Hollow Country Club submitted to
Michigan State University for disease diagnosis
October 1, 2009 - Michigan State reported to Quail Hollow that the
problem was a bacterial disease caused by a species of Acidovorax
October 2, 2009 - attempted to contact Dr. Vargas for information
May 19, 2010 - received response from Paul Giordano:

79. Communication from MSU on May 19, 2010

80. Communication from MSU on May 19, 2010
....we believe the bacterium is the causal organism, or at least partially
responsible for the issue....

81. Communication from MSU on May 19, 2010
....we believe the bacterium is the causal organism, or at least partially
responsible for the issue....
....we are still in the beginning stages of investigating this problem, and
would like to have sound scientific evidence supporting our
conclusions before giving any concrete answers....

82. Communication from MSU on May 19, 2010
....we believe the bacterium is the causal organism, or at least partially
responsible for the issue....
....we are still in the beginning stages of investigating this problem, and
would like to have sound scientific evidence supporting our
conclusions before giving any concrete answers....
....we would like to initiate some collaborative research with your lab
aimed at positive identification of the problem....

83. Plant Disease Note,
Published July 2009
• ...a golf course putting green
sample...
• ...symptoms of general wilt, decline,
and characteristic necrosis...
• ...bacterial streaming was present in
all of the infected tissue...
• ...3 different bacteria were isolated...
• ...one resulted in slight browning of
leaf tips just 2 days after inoculation...

84. Plant Disease Note,
Published July 2009
• ...when leaf tips of the inoculated
plants were cut, bacterial streaming
was observed...
• ...DNA sequencing results indicated
that the causal agent was a member
of the Acidovorax genus...
• ...this is the first report of a bacterial
disease affecting creeping bentgrass
caused by Acidovorax spp. in the US.

85. Photo by Paul Giordano, Michigan State University

91. GCM, November 2006

92. How most labs are diagnosing ‘bacterial wilt’.

94. The diagnostic
lab saw some bacteria
in our samples.

95. Which bacteria
did they see? Is it a
pathogen?
The diagnostic
lab saw some bacteria
in our samples.

96. Which bacteria
did they see? Is it a
pathogen?
The diagnostic
lab saw some bacteria
They didn’t say, but in our samples.
clearly we have a huge bacteria
problem here.

97. Which one is a
pathogen?

98. 2010
Acidovorax sp.
Xanthomonas translucens
No suspected pathogens

99. 2011
Acidovorax sp.
Xanthomonas translucens
Both Acidovorax and
Xanthomonas
No suspected pathogens

100. Management of Bacterial Diseases in Turf

101. Management of Bacterial Diseases in Turf
ALLEVIATE STRESS!

102. Management of Bacterial Diseases in Turf
ALLEVIATE STRESS!
• raise mowing heights
• reduce mowing frequency
• mow in evening or when turf is dry
• avoid abrasive practices such as aerification or topdressing
• LIGHT and FREQUENT applications of complete foliar fertilizers
• irrigate in morning to prepare for heat of day, ensure that foliage
dries in between syringe cycles

103. What are the chemical control options?

104. What are the chemical control options?
• streptomycin sulfate (Agrimycin 17, FireWall)

105. What are the chemical control options?
• streptomycin sulfate (Agrimycin 17, FireWall)
• oxytetracycline (Mycoshield, FireLine)

106. What are the chemical control options?
• streptomycin sulfate (Agrimycin 17, FireWall)
• oxytetracycline (Mycoshield, FireLine)
• hydrogen dioxide (Zerotol, Redox, etc)

107. What are the chemical control options?
• streptomycin sulfate (Agrimycin 17, FireWall)
• oxytetracycline (Mycoshield, FireLine)
• hydrogen dioxide (Zerotol, Redox, etc)
• n-Alkyl ammonium chloride (Consan 20, Greenshield, SA-20)

108. What are the chemical control options?
• streptomycin sulfate (Agrimycin 17, FireWall)
• oxytetracycline (Mycoshield, FireLine)
• hydrogen dioxide (Zerotol, Redox, etc)
• n-Alkyl ammonium chloride (Consan 20, Greenshield, SA-20)
• copper (Junction, Camelot, Copper-Count-N)

109. What are the chemical control options?
• streptomycin sulfate (Agrimycin 17, FireWall)
• oxytetracycline (Mycoshield, FireLine)
• hydrogen dioxide (Zerotol, Redox, etc)
• n-Alkyl ammonium chloride (Consan 20, Greenshield, SA-20)
• copper (Junction, Camelot, Copper-Count-N)
• fosetyl-Al (Signature, Autograph, Fosetyl-Al, Prodigy)

110. What are the chemical control options?
• streptomycin sulfate (Agrimycin 17, FireWall)
• oxytetracycline (Mycoshield, FireLine)
• hydrogen dioxide (Zerotol, Redox, etc)
• n-Alkyl ammonium chloride (Consan 20, Greenshield, SA-20)
• copper (Junction, Camelot, Copper-Count-N)
• fosetyl-Al (Signature, Autograph, Fosetyl-Al, Prodigy)
• acibenzolar (component of Daconil Action)

111. What are the chemical control options?
• streptomycin sulfate (Agrimycin 17, FireWall)
• oxytetracycline (Mycoshield, FireLine)
• hydrogen dioxide (Zerotol, Redox, etc)
• n-Alkyl ammonium chloride (Consan 20, Greenshield, SA-20)
• copper (Junction, Camelot, Copper-Count-N)
• fosetyl-Al (Signature, Autograph, Fosetyl-Al, Prodigy)
• acibenzolar (component of Daconil Action)
• fluazinam (experimental)

112. L-93, Raleigh NC
Signature (8 oz)
Dac Action (3.6 oz)
Mycoshield (3.7 oz)
Clorox (3 fl oz)
Hydrogen Peroxide (3 fl oz)
Junction (4 oz)
Camelot (3 fl oz)
Untreated
0 5 10 15 20
Disease Incidence (%)
Data collected June 23,
2011

113. G-2, Charlotte NC
Signature (8 oz)
Dac Action (3.6 oz)
Mycoshield (3.7 oz)
Ningnanamycin (1 oz)
Untreated
0 3 6 9
Disease Severity (0 to 9)
June 13 June 20 June 27 July 5

114. G-2, Charlotte NC
Mycoshield (10 lbs/A) Agrimycin (10 lbs/A)
Kasumin (1.5 fl oz/M) Untreated
6
a
ab
Disease Severity (0 to 9)
4.5
a
ab ab
3 ab b
b
1.5
a
a a
a
0
June 27 July 5 July 18
Treatments applied June 27, July 5, and July 12

115. Dominant, Raleigh NC
FireLine (10 lbs/A)
FireWall (10 lbs/A)
Dac Action (3.6 oz)
Zerotol (6 oz)
SA-20 (1.6 oz)
Junction (3 oz)
Camelot (3 oz)
Cu-Count-N (16 oz)
Signature (8 oz)
Signature (4 oz)
Untreated
0 3 6 9
Data collected July 8

116. Dominant, Raleigh NC
FireLine (10 lbs/A)
FireWall (10 lbs/A)
Dac Action (3.6 oz)
Zerotol (6 oz)
SA-20 (1.6 oz)
Junction (3 oz)
Camelot (3 oz)
Cu-Count-N (16 oz)
Signature (8 oz)
Signature (4 oz)
Untreated
0 3 6 9
Data collected July 20

117. Dominant, Raleigh NC
FireLine (10 lbs/A)
FireWall (10 lbs/A)
Dac Action (3.6 oz)
Zerotol (6 oz)
SA-20 (1.6 oz)
Junction (3 oz)
Camelot (3 oz)
Cu-Count-N (16 oz)
Signature (8 oz)
Signature (4 oz)
Untreated
0 3 6 9
Data collected August 8

120. turfdiseases.org

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