New Grass and Broadleaf Weed Management

Options in Coastal Bermudagrass Pastures

L. Warren, F. Yelverton and T. Gannon

North Carolina State University

Introduction

Grass Weeds

Interfere when striving for pure stands

(horse owners, hog waste producers)

Interfere with hay drying

Generally not a health concern except johnsongrass

Broadleaf Weeds

Numerous, noxious, toxic, prickly (animals will not

graze)

Common and / or Troublesome Weeds

Large crabgrass Pigweed species Chickweed species

Goosegrass* Blackberry Henbit

Foxtail species Horsenettle Wild radish / mustard

Sandbur species Buttercup species

Paspalum species Curly dock

Johnsongrass

Italian ryegrass* *Possible 2012 additions

2008 Weed Survey – Southern States (North Carolina)

Introduction

Pastora (nicosulfuron + metsulfuron)

Registered in 2010 for bermudagrass pastures

Broadleaf as well as grass herbicide

Perspective (aminocyclopyrachlor + chlorsulfuron)

2013 target registration date

Broadleaf herbicide

Research Objectives

To evaluate efficacy of Pastora and Perspective

applied at various timings for postemergence

control of important summer and winter pasture

weeds

To evaluate growth response of ‘Coastal’

bermudagrass when treated at various timings

Procedures

• Plot sizes (4 reps)

6 x 15 to 8 x 25 ft plots

• Spray information

Treatments applied with 18 in spacing 4-nozzle boom

containing XR 110002VS nozzles delivering 20

gpa at 32-34 psi and 3 mph

• Evaluation parameters

Control, bermuda stand reduction and chlorosis

0-100% scale; data subjected to ANOVA p=.05

Treatment List

Pastora + NIS* 1 oz/A + 0.25%

Pastora + NIS 1.5 oz/A + 0.25%

Pastora + COC** 1 oz/A + 1%

Pastora + COC 1.5 oz/A + 1%

Perspective + NIS 1.19 to 4.76 oz/A + 0.25%

(2 to 2.5 oz/A)

*NIS = Induce

**COC = Agridex

Large Crabgrass Control in Coastal

Bermudagrass using Pastora

0

20

40

60

80

100

1 oz/A Pastora +

0.25% NIS

Check

Treated Apr 15

Rated Jul 8

Treated Jun 8

Rated Jul 8

Treated Jun 15

Rated Jul 8

2009: Wake County

% C

on

trol

c a a c c c

2009 Wake County Trial Discussion

Apr 15 application date: Italian ryegrass was 8 to 12

inches tall with density of 3 plants per ft2

Little barley was 3 to 5 inches and 1 plant per ft2

Large crabgrass had not germinated due to heavy

winter weed infestations (0% control)

Jun 3: 1st harvest date

Jun 8 application date: Large crabgrass just

germinating at 1 to 2 leaves and 1 inch tall

Jun 15 application date: Large crabgrass 3 to 4

leaves and 1 to 2 inches tall

Large Crabgrass Control and Coastal

Bermudagrass Stand Reduction

0

20

40

60

80

100

Digsa

Sep 3

Stand

May 7

Stand

Jun 25

Stand

Jul 21

Pastora 1 oz/A

Apr 21

Pastora 1.5 oz/A

Apr 21

Pastora 1 oz/A

Apr 21 and Jun 11

Panoramic 0.25 pt/A

Apr 21

Check

2009: Bladen County

13 9 3 2 LSD (P=.05)

0.25% NIS added

to all trts

2009 Bladen County Trial Discussion

Winter weed infestation extremely light

Apr 21: Trial initiated

Large crabgrass 1 to 3 leaves and 0.75 inch tall and

not heavily populated

Panoramic bermuda effects observed through Jul

Jun 4: 1st harvest date

Jun 25: 1 oz/A Pastora applied Jun 11 slightly

stunted bermudagrass growth with peak symptoms

at 2 WAT and full recovery by 4 WAT

Pastora 1 oz/A + 0.25% NIS

May 20, 2009 (4 WAIT)

Panoramic 0.25 pt/A + 0.25% NIS

May 20, 2009 (4 WAIT)

Goosegrass Control and Coastal

Bermudagrass Stand Effects

0

20

40

60

80

100

ELEIN Jul 8 % COVER Jul 8

Pastora + NIS

1 oz/A + 0.25%

Roundup Powermax +

NIS 6 fl oz/A + 0.25%

Pastora + Roundup

Powermax + NIS

1 oz/A + 6 fl oz/A +

0.25%

Check

2010: Bladen County

7 19 lsd p=.05

Jun 9, 2010

Application date

2010 Bladen County Trial Discussion

Test area heavily infested with Italian ryegrass and

other winter weeds

Jun 4: 1st cutting to remove mainly ryegrass

Jun 9 application date:

Heavy infestation of goosegrass ranging from 2

leaves to 2+ tillers and 2 to 6 inches tall (1 tiller

and 4 inch tall avg.)

Pastora + NIS

1 oz/A + 0.25%

Treated Jun 9

Photo Jul 8

Check

Italian Ryegrass Control – Sampson Co.

Rate Appl Date Eval Date Control

1.5 oz 03-06-09 05-26-09 93

1 oz 04-15-09 05-26-09 100

1 oz 01-14-10 04-21-10 96

1.5 oz 01-14-10 04-21-10 98

1 oz 03-09-10 04-21-10 96

1.5 oz 03-09-10 04-21-10 100

1 oz 12-21-10 04-05-11 98

1 oz 02-15-11 04-05-11 90

2009-11 Italian Ryegrass Trial Discussion

Pastora applied at 1 oz/A or 1.5 oz/A provided

excellent LOLMU control (>90%) regardless of

timing

LOLMU was heavily infested and ranged from 4 to

12 inches in height at any application date

Mar 8, 2011

Discussion

Pastora Label Highlights

Foxtail and ryegrass spp. (2”); sandbur spp. (1.5”)

Johnsongrass (up to 18”)

Bahiagrass (before seedhead formation)

Large crabgrass and goosegrass (suppression only)

No restrictions; no long-term bermuda injury at any timing

Buckhorn Plantain Control in

Bermudagrass using Perspective

0

20

40

60

80

100

Mar 10 Spray Jun 3 Spray Oct 8 Spray

Perspective 1.19 oz/A

Perspective 2.38 oz/A

Perspective 4.76 oz/A

Check

2009: Wake County

2 17 41 lsd p=.05

0.25% v/v NIS

% C

ontr

ol

2 WAT 4 WAT

Effect of Perspective on Bermudagrass

0

20

40

60

80

100

Mar 10 Spray Jun 3 Spray Oct 8 Spray

Perspective 1.19 oz/A

Perspective 2.38 oz/A

Perspective 4.76 oz/A

Check

2009: Wake County

0 7 0 lsd p=.05

0.25% v/v NIS

% C

hlo

rosi

s

Symptoms Jun 15; Recovery Jun 29

Perspective Effects on Various Weeds 1.19 oz/A

DIORE 100% (Jun); 23% (Oct) 2009

2 oz/A

RAPRA 80% and RUMCR 100% (Mar) 2011

2.167 oz/A

RANSA, VERAR and TAROF 100% (Mar) 2010

2.5 oz/A

STEME, CERVU, BRSNI, RANAR, GERCA, RUMCR,

ARTVU 100%; CAPBP 98% (Jan) 2011

SOLCA and POLLA 100%; EUPCP 98%; CASOB 85%;

CMIRA 60%; PAQIN 0% (May) 2011

Discussion

Perspective (aminocyclopyrachlor + chlorsulfuron)

Horsenettle Buckhorn & bdlf plantain Purple cudweed

Curly & bdlf dock Carolina geranium Florida pusley

Henbit Facelis White clover

Hairy buttercup* Brazilian catsear Wild violet

Corn buttercup* Purple deadnettle Goldenrod

Common chickweed* Common lespedeza Hop clover

Mustard / pigweed Lawn burweed Bdlf pink purslane

Horseweed Common dandelion Bracted plantain

Virginia buttonweed Lindheimer panicgrass Dichondra

Florida betony Annual blue-eyed grass Dogfennel

Sicklepod Polygonum spp. Dollarweed

Conclusions

1 or 1.5 oz/A Pastora provided excellent (>90%) control of

large crabgrass up to 4 leaves, goosegrass up to 1 tiller and

Italian ryegrass up to 12 inches in height.

1 oz/A Pastora applied in Jun (1 WA cutting) caused

temporary bermudagrass growth reduction and

discoloration (16%) by 2 WAT with total recovery by 4

WAT.

Timely applications of Perspective up to 2.5 oz/A provided

excellent (>90%) control of the common and troublesome

NC pasture bdlf weeds tested except for wild radish (80%).

Conclusions

Perspective also provided >90% control of dichondra, corn

speedwell, common dandelion, Carolina geranium,

mugwort, hairy bittercress, ladysthumb and dogfennel.

2.38 or 4.76 oz/A Perspective applied in Jun yellowed

bermudagrass 11 or 14%, respectively 2 WAT; no injury

symptoms were evident at 4 WAT.

Pastora is and Perspective should be an excellent herbicide

option for NC bermudagrass pasture growers.