Weed Control Strategies for Athletic Fields in North Carolina Travis Gannon North Carolina State University 919.513.4655 email: travis_gannon@ncsu.edu web: 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 www.turffiles.ncsu.edu
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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 Included Trade 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
% Control Annual Bluegrass Control 100 90a 80 60 80ab 70abc 53c Barricade.5 Barricade.75 Ronstar 2 40 Pendulum 2 20 0 Rates are lb ai/a applied 10 WBO, ratings taken 5-8, Forest Oaks CC, 2001
% Control Annual Bluegrass Control 100 94a 94a 80 71abc Barricade.38 60 40 56bc 45c Barricade.5 Ronstar 2 Pendulum 2 20 Dimension.5 0 Rates are lb ai/a applied 8 WBO, ratings taken 5-8, Forest Oaks CC, 2001
% Control Annual Bluegrass Control 100 80 89a 88a 91a 80ab Dimension.5 6WBO 60 Balan 2.75 6WBO 40 20 0 Balan 2 X 2.75 6WBO&6WAO Barricade 2 X.38 8WBO&4WAO Rates are lb ai/a, ratings taken 5-8, Forest Oaks CC, 2001
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
% Control Annual Bluegrass Control 100 80 60 40 50 76 36 34 98 99 Velocity 1.3 oz x 2 Velocity 2 oz x 2 Velocity 2.6 fb 1.3 oz 20 0 0 0 4 WAIT 8 WAIT Nontreated Rates are per acre, initially applied 2-15, Tobacco Road GC, 2005
% Control Annual Bluegrass Control 100 100 100 80 60 40 20 0 39 71 49 18 0 0 4 WAIT 8 WAIT Velocity 1.3 fb 2.6 oz 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 1.32 oz/a x 3 Velocity 0.66 oz/a x 3
Velocity 2.6 fb 1.3 oz/a Velocity 1.3 fb 2.6 oz/a
Velocity 2 oz/a x 2 Velocity 1.3 oz/a x 2
Conclusions The following treatments provided acceptable annual bluegrass control: Velocity 2 fb 2 oz Velocity 2.6 fb 1.3 oz Velocity 1.3 fb 2.6 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
% Control Poa annua Control in Non- Overseeded Bermudagrass 100 80 60 40 53 51 84 99 98 100 Revolver 0.4 fl oz Revolver 0.8 fl oz Roundup Pro 1 qt 20 0 0 0 10 2 WAT 4 WAT 8 WAT 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
% Control Poa annua Control in Non- Overseeded Bermudagrass 100 80 60 90 53 65 88 99 92 100 Revolver 0.2 oz Revolver 0.4 oz 40 20 11 20 18 28 15 Monument 0.47 oz + NIS Roundup Pro 1 pt 0 30 DAT 60 DAT 120 DAT Revolver rates are per 1000 ft², others are per acre applied 1-13-04. Poa annua was tillered at application.
% Control Poa annua Control in Non- Overseeded Bermudagrass 100 80 60 64 85 79 95 64 79 99 100 99 54 Princep 1 lb Monument 0.33 oz Revolver 0.4 40 TranXit 1 oz 20 Certainty 1.33 oz 0 2 MAT 3 MAT 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 Herbicides Use 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
and very phytotoxic to perennial ryegrass Metsulfuron is highly water soluble
Precautions for Using Postemergence Annual Bluegrass Herbicides Single 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
% green-up Glyphosate sprayed at 33gpa on 3-29-99 with XR11003 nozzles Spraying Glyphosate on Partially (15%) Greened- Up Tifway Bermudagrass 100 80 79 71 65 80 Roundup Pro 8oz Roundup Pro 12 oz 60 50 53 Roundup Pro 16 oz 40 31 30 Roundup Pro 24 oz 20 20 18 15 13 Roundup Pro 32 oz 0 9 DAT 24 DAT LSD 8.0 LSD 8.6 Nontreated
% green-up Spraying Glyphosate on Partially (15%) Greened- Up Tifway Bermudagrass 100 80 60 97 96 96 98 98 96 93 95 98 83 86 89 Roundup Pro 8oz Roundup Pro 12 oz Roundup Pro 16 oz 40 20 0 Roundup Pro 24 oz Roundup Pro 32 oz Nontreated 49 DAT 57 DAT LSD 6.7 LSD 5.5 Glyphosate sprayed at 33gpa on 3-29-99 with XR11003 nozzles
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
Sulfonylurea Herbicides Certainty - sulfosulfuron Manor, Blade, Quali Pro MSM - metsulfuron Revolver - foramsulfuron Monument - trifloxysulfuron Tranxit - rimsulfuron
Bermudagrass 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 Duble, 1996
Shade Tolerance of Various Turfgrasses Cool-Season Species creeping bentgrass Kentucky bluegrass rough bluegrass tall fescue fine fescue Shade Tolerance fair very poor excellent good excellent Beard (2002)
Shade Tolerance of Various Turfgrasses (cont.) Warm-Season Species St. Augustine zoysiagrass centipedegrass bermudagrass Shade Tolerance excellent good medium very poor Beard (2002)
Bermudagrass Under low light (<60% full sunlight), bermudagrass develops narrow, elongated leaves, thin upright stems, elongated internodes, and weak rhizomes Duble, 1996
Spring Transition The Problem Turf-type cool-season ryegrass cultivars that perform well during the autumn overseeding establishment 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 Beard (2002)
Bermudagrass spring transition (cont.) Biological indicator for greenup initiation 62 F at 4 inch depth Beard (2002)
Bermudagrass spring transition (cont.) Minimizing spring transition problems Lower mowing height Increased nitrogen fertility Light vertical mowing Core aerification Beard (2002)
Treatments Ammonium nitrate (4-25 & 6-13) -applied at 2 lbs / 1000ft 2 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
Summary Verticutting, core aerifications and later ammonium nitrate application did not affect ryegrass transition. Horgan & Yelverton, Crop Sci.
Summary The 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.
Problem with Overseeded Bermudagrass Trend to hold perennial ryegrass too long in the spring and overseed too early in the fall
How Much Growth Does Bermudagrass Need (w/o ryegrass competition)? About 100 days (Observation) Anything less will lead to a gradual decline of bermudagrass over time
Spring Transition- What Happens to Bermudagrass? 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.
Spring Transition- What Happens to Bermudagrass? Bermudagrass that is not well-established should not be overseeded.
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
% Control Removal of Overseeded Perennial Ryegrass in Bermudagrass with Herbicides 100 80 60 40 46bc 45bcd 61b 54bc 93a 95a 91ab 95a 39def Monument 0.3 oz TranXit 1 oz Manor 0.5 oz Revolver 17.4 oz Kerb 1 lb ai 20 0 14hi 2 WAT 4 WAT 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.
Green Kyllinga (Kyllinga brevifolia) & False Green Kyllinga (K. gracillima)
% Control False Green Kyllinga Control with Sulfentrazone 100 80 80 83 89 84.25 lb ai.375 lb ai 60.25 fb.25 lb ai 40 20 0 26 21 8 0 Dismiss 4F sulfentrazone 0.3G.375 fb.375 lb ai LSD=11.0 Data collected 8-21-06, 82 DAIT. Rates are lb ai per acre. Sequential applied 6 WAIT.
% Control 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. False Green Kyllinga Control with Sulfonylureas 100 94 91 90 89 95 80 78 1 application 60 40 20 2 applications LSD=11.0 0 Monument Sedgehammer Certainty
Dallisgrass (Paspalum dilatatum)
MSMA fb Rev 2 fl oz/1000 ft 2 2WAIT fb MSMA 3WAIT Photo: 12 WAIT
MSMA fb Rev 2 fl oz/1000 ft 2 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: travis_gannon@ncsu.edu web: www.turffiles.ncsu.edu