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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.