weed control strategies for athletic fields in north … · weed control strategies for athletic...

Weed Control Strategies for Athletic Fields in

North Carolina

Travis Gannon

North Carolina State University

919.513.4655

email: [email protected]

web: www.turffiles.ncsu.edu

www.TurfFiles.ncsu.edu

What We’ll Talk About:

Proposed EPA bans

Annual bluegrass control

Overseeded areas

Nonoverseeded areas

Ryegrass removal

Herbicides for kyllinga spp. and

dallisgrass control

TurfFileswww.TurfFiles.ncsu.edu

Find this

presentation and

more online

Sign-up for

Turf ALERTS

Learn about

turfgrass pests:

•Weeds

•Insects

•Diseases

Identify your turf or

weed species using

Decision Aids

www.TurfFiles.ncsu.edu

Old Herbicides

EPA Proposed Bans:

MSMA, DSMA, CMA

Triazine herbicides

Annual Bluegrass Control in

Overseeded Bermudagrass

Problems with Overseeding Bermudagrass

• Decreased herbicide options for weed control

• Increased weed incidence

– annual bluegrass

Problems with Overseeding

annual bluegrass

Tufted, clumped winter annual

Yellow – green

Prolific seed producer

Encouraged by seed bed preparation

Products IncludedTrade Name Form. Common Name Overseeding Rest.

Balan 2.5G benefin 6-8 weeks

Barricade 65WG prodiamine 8 weeks

Dimension 40WP dithiopyr 8 weeks

Pendulum 60WG pendimethalin 12 weeks

Ronstar 2G oxadiazon 16 weeks

Annual Bluegrass Control

0

20

40

60

80

100

% C

on

trol

Barricade .5

Barricade .75

Ronstar 2

Pendulum 2

Rates are lb ai/a applied 10 WBO, ratings taken 5-8, Forest Oaks CC, 2001

80ab

90a

70abc

53c


0

20

40

60

80

100

% C

on

trol

Barricade .38

Barricade .5

Ronstar 2

Pendulum 2

Dimension .5

Rates are lb ai/a applied 8 WBO, ratings taken 5-8, Forest Oaks CC, 2001

94a 94a

71abc

56bc

45c


0

20

40

60

80

100

% C

on

trol

Dimension .5 6WBO

Balan 2.75 6WBO

Balan 2 X 2.756WBO&6WAO

Barricade 2 X .388WBO&4WAO

Rates are lb ai/a, ratings taken 5-8, Forest Oaks CC, 2001

89a 91a88a80ab

Nontreated

Barricade .75 10WBO

Barricade .5 10WBO

Ronstar 2 10WBO

Pendulum 2 10WBO

Barricade .5 8WBO

Barricade .38 8WBO

Barricade 2 x .38

8WBO&4WAO

Ronstar 2 8WBO

Pendulum 2 8WBO

Dimension .5 8WBO

Dimension .5 6WBO

Balan 2.75 6WBO

Balan 2 x 2.75

6WBO&6WAO

Clogged nozzle with Barricade application

Conclusions

Across locations and years, Barricade applied at 0.5 lb ai/a provided acceptable control in all three trials

Across locations and years, the following treatments provided acceptable annual bluegrass control in two of three trials:Barricade 0.6 lb ai/a 8 WBO

Barricade 0.4 lb ai/a 8 WBO

Dimension Ultra 0.5 lb ai 6 WBO

Balan 2.75 lb ai/a 6 WBO

Conclusions

Number of annual bluegrass germination

flushes will vary

Control less than optimum in years with multiple

flushes later in the season

To optimize control, utilize preemergent AND

postemergent herbicide


36 34

50

98

76

99

0 00

20

40

60

80

100

4 WAIT 8 WAIT

% C

on

tro

l

Velocity 1.3 oz x 2

Velocity 2 oz x 2

Velocity 2.6 fb 1.3 oz

Nontreated

Rates are per acre, initially applied 2-15, Tobacco Road GC, 2005


39

100

18

71

49

100

0 00

20

40

60

80

100

4 WAIT 8 WAIT

% C

on

tro

l


Velocity 0.66 oz x 3

Velocity 1.3 oz x 3

Nontreated

Rates are per acre, initially applied 2-15, Tobacco Road GC, 2005

Velocity 0.66 oz/a x 3


Velocity 1.3 fb 2.6 oz/a

Velocity 2.6 fb 1.3 oz/a


Velocity 2 oz/a x 2

Conclusions

The following treatments provided acceptable annual bluegrass control:

Velocity 2 fb 2 oz



Velocity 1.3 fb 1.3 fb 1.3 oz

However, perennial ryegrass phytotoxicity will range from 10 – 30%, regardless of rate regime

Postemergence Annual Bluegrass Control in

Nonoverseeded Areas

Poa annua Control in Non-


0

53

99

0

51

98

10

84

100

0

20

40

60

80

100

2 WAT 4 WAT 8 WAT

% C

on

tro

l

Revolver 0.4 fl oz

Revolver 0.8 fl oz

Roundup Pro 1 qt

Rates are product per acre applied 3-14-01. Poa annua was

3-8 tiller w/ seedheads at application. Quail Ridge, 2001

Nontreated

Revolver 0.4 oz/M

Roundup Pro 1 qt/a



11

53

28

20

65

92

18

88

100

90

99

15

0

20

40

60

80

100

30 DAT 60 DAT 120 DAT

% C

on

tro

l

Revolver 0.2 oz

Revolver 0.4 oz

Monument 0.47 oz + NIS

Roundup Pro 1 pt

Revolver rates are per 1000 ft², others are per acre applied 1-13-04. Poa annua was tillered at application.



64

7985

99

79

10095

99

64

54

0

20

40

60

80

100

2 MAT 3 MAT

% C

on

tro

l

Princep 1 lb

Monument 0.33 oz

Revolver 0.4

TranXit 1 oz

Certainty 1.33 oz

Revolver rates are per 1000 ft², others are per acre applied 11-12-03.

Princep 1 lb ai /A

AAtrex 1 lb ai / A

Roundup Pro 1 lb ai / A

Treated Dec 22, 2003 Photo Feb 5, 2004

Conclusions

The following treatments provided acceptable annual bluegrass control through 120 DAT when applied mid-January:

Revolver 0.4 oz/M

Monument 0.47 oz/a

Applied mid-November, Monument (0.33 oz/a), Revolver (0.4 oz/M), and TranXit (1 oz/a) provided excellent control through 3 months after treatment. However, at 6 months after treatment, Monument provided good control while Revolver continued to provide excellent control.

Precautions for Using

Sulfonylurea HerbicidesUse around sensitive areas

Lateral movement

Tracking

Applied early, control will break

Timing of application is crucial

Decreased herbicide performance if cool weather persists

after application

Metsulfuron is

highly water

soluble…

…and very

phytotoxic to

perennial ryegrass

Precautions for Using Postemergence

Annual Bluegrass HerbicidesSingle application of simazine – control may break

Single application – 2 lb ai/a Nov 15

With sequential application – 1 lb ai/a – Oct 15 fb Dec 15

Do not apply after Jan 01

glyphosate

Provides no residual

May delay bermudagrass greenup

Spraying Glyphosate on Partially (15%) Greened- Up

‘Tifway’ Bermudagrass

31

79

20

71

15

53

13

30

65

18

80

50

0

20

40

60

80

100

9 DAT 24 DAT

Roundup Pro 8oz

Roundup Pro 12 oz

Roundup Pro 16 oz

Roundup Pro 24 oz

Roundup Pro 32 oz

Nontreated

Glyphosate sprayed at 33gpa on 3-29-99 with XR11003 nozzles

LSD 8.0 LSD 8.6

% g

reen

-up

Spraying Glyphosate on Partially (15%) Greened- Up

‘Tifway’ Bermudagrass

97 9893

98

83

96

86 899596 9896

0

20

40

60

80

100

49 DAT 57 DAT

Roundup Pro 8oz

Roundup Pro 12 oz

Roundup Pro 16 oz

Roundup Pro 24 oz

Roundup Pro 32 oz

Nontreated

Glyphosate sprayed at 33gpa on 3-29-99 with XR11003 nozzles

LSD 6.7 LSD 5.5

% g

reen

-up

Conclusions - PRE

In nonoverseeded areas, prodiamine (Barricade) may be an option for preemergence control of winter annuals

Depends if your field has recovered

0.75 – 1.0 lb ai/a applied September 01

Overseeded Ryegrass Removal

Certainty - sulfosulfuronManor, Blade, Quali Pro MSM - metsulfuron

Revolver - foramsulfuron

Monument - trifloxysulfuron

Tranxit - rimsulfuron

Sulfonylurea Herbicides

Bermudagrass has a high light requirement

and does not grow well under low light or

shady environments

Increased light intensity and daylength

increase rhizome, stolon, and leaf growth

Bermudagrass

Duble, 1996

Shade Tolerance of Various Turfgrasses

Cool-Season Species Shade Tolerance

creeping bentgrass fair

Kentucky bluegrass very poor

rough bluegrass excellent

tall fescue good

fine fescue excellent

Beard (2002)

Shade Tolerance of Various Turfgrasses (cont.)

Warm-Season Species Shade Tolerance

St. Augustine excellent

zoysiagrass good

centipedegrass medium

bermudagrass very poor

Beard (2002)

Under low light (<60% full sunlight),

bermudagrass develops narrow, elongated

leaves, thin upright stems, elongated

internodes, and weak rhizomes

Bermudagrass

Duble, 1996

Turf-type cool-season ryegrass cultivars that perform well during the autumn overseedingestablishment and winter playing season tend to persist well into the spring and early summer

Canopy shading results in impaired bermudagrass greenup and possible stand loss

Spring Transition – The Problem

Beard (2002)

Biological indicator for greenup initiation

62 F at 4 inch depth

Bermudagrass – spring transition (cont.)

Beard (2002)

Minimizing spring transition problems

Lower mowing height

Increased nitrogen fertility

Light vertical mowing

Core aerification

Bermudagrass – spring transition (cont.)

Beard (2002)

TreatmentsAmmonium nitrate (4-25 & 6-

13)

-applied at 2 lbs / 1000ft2 to wet turf foliage

Core cultivation *

Pronamide

-applied at 1 lb ai/a

Scalping *

Vertical mowing *

Vertical mowing / scalping *

Nontreated

* Treatments repeated every 2 weeks

SummaryVerticutting, core aerifications and later

ammonium nitrate application did not

affect ryegrass transition.

Horgan & Yelverton, Crop Sci.

SummaryThe perennial ryegrass in all treatments

transitioned out at the same rate as the

nontreated plots

Thus environmental conditions ultimately

dictated transition of overseeded perennial

ryegrass to bermudagrass

Horgan & Yelverton, Crop Sci.

Trend to hold perennial ryegrass too long in

the spring and overseed too early in the fall

Problem with Overseeded

Bermudagrass

About 100 days (Observation)

Anything less will lead to a gradual decline

of bermudagrass over time

How Much Growth Does Bermudagrass

Need (w/o ryegrass competition)?

Bermudagrass is aggressive – so is

perennial ryegrass.

In spring, competitive edge heavily favors

perennial ryegrass.

It’s all about plant competition for resources!

Spring Transition- What Happens

to Bermudagrass?

Long-term health of bermudagrass will

hinge on successfully growing it back in

prior to overseeding in the fall.


to Bermudagrass?

Bermudagrass that is not well-established

should not be overseeded.


to Bermudagrass?

Herbicide Application Rates

Kerb 1.0 lb ai/a

Manor or Blade 0.5 oz/a + NIS

Revolver 0.4 oz/M or 18 oz/a

Monument 0.3 oz/a + NIS

Tranxit 1.0 oz/a + NIS

Certainty 1.33 oz/a + NIS

What Are The Issues With

Herbicde Use?

Costs: ranges from $40-$100/acre

How fast do you want to kill it?

Dead and dying ryegrass is not pretty

Herbicides are mobile

What Is The Best Herbicide To

Use?

All five are effective in removing

ryegrass (some also kill Poa annua)

The speed they remove ryegrass

differs

Speed Of Kill with Transition

Herbicides

Revolver = Monument = Tranxit are faster

than Manor which is faster than Kerb.

Speed of Kill with Transition

Herbicides

Revolver, Monument, Tranxit

14 – 21 days

Manor or Blade

21 – 28 days

Kerb

28 – 45 days

Removal of Overseeded Perennial Ryegrass in

Bermudagrass with Herbicides

0

20

40

60

80

100

2 WAT 4 WAT

% C

ontr

ol

Monument 0.3 oz

TranXit 1 oz

Manor 0.5 oz

Revolver 17.4 oz

Kerb 1 lb ai

46bc45bcd

61b

54bc

95a91ab

95a

39def

Rates are per acre applied June 2, 2003. Means within a rating date followed by same letter(s) are not

significantly different (P=0.05). NCSU Turf Field Lab 2003.

14hi

93a

Green Kyllinga (Kyllinga brevifolia) & False

Green Kyllinga (K. gracillima)

False Green Kyllinga Control with Sulfentrazone

26

0

80

8

83

21

8984

0

20

40

60

80

100

Dismiss 4F sulfentrazone 0.3G

% C

on

tro

l

.25 lb ai

.375 lb ai

.25 fb .25 lb ai

.375 fb .375 lb ai

Data collected 8-21-06, 82 DAIT. Rates are lb ai per acre. Sequential applied 6 WAIT.

LSD=11.0

False Green Kyllinga Control with Sulfonylureas

94

78

8991 9095

0

20

40

60

80

100

Monument Sedgehammer Certainty

% C

on

tro

l

1 application

2 applications

Monument – 0.56 oz, Sedgehammer – 1.33 oz, Certainty – 1.25 oz/a + NIS. Data collected 8-

21-06, 82 DAIT. Sequential applied 6 WAIT.

LSD=11.0

Dallisgrass (Paspalum dilatatum)

MSMA fb Rev 2 fl

oz/1000 ft2

2WAIT fb MSMA

3WAIT

Photo: 12 WAIT

MSMA fb Rev 2 fl

oz/1000 ft2

2WAIT fb MSMA

3WAIT

Photo: 1 YAIT

Certainty 1.25 oz/A + MSMA 2 lb ai/A + NIS 0.25%

applied May 2 and June 13, 2005 Photo June 27

QUESTIONS?

Travis Gannon

North Carolina State University

919.513.4655

email: [email protected]

web: www.turffiles.ncsu.edu

weed control strategies for athletic fields in north … · weed control strategies for athletic...

Documents