Weed Control in Sod Production Fields

Tim R. Murphy

The University of Georgia

Weed Problems in Sod

Intensive irrigation and fertility effectsEffect of herbicides on sodRow crop weedsCommon bermudagrass controlRow crop vs. turf herbicides

– Same ai and formulation

Cultural Control

Avoid over-irrigationInstall drainage if neededProperly mow on schedule

– Will control most tall-growing broadleaf weeds

Maintain pH and fertilityControl insects and diseasesKnow weed spectrum

Hit or Miss

Vs.

Planned Program

PrePlant Weed Control

Essential for common bermudagrass control– Will require one fallow season

Roundup Pro– Still the best herbicide unless fumigation is used– Repeat applications will be needed

Roundup Rate and Bermudagrass Control

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2 qts 5 qts 10 qts

Roundup Rate/Acre

53 DAT 116 DAT

DAT = Days after Treatment

Bermuda Control with Roundup – 1 yr.

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4qt/2X 2qt/3X 2qt/2X

Rate Qt/Acre / No. of Apps.

Bermudagrass Control with Roundup (averaged across Tifway, Tifgreen, Tifdwarf, Ormond)

Rate (qt.acre) Applications% BermudaRegrowth

2.0 2 472.0 3 13.0 2 263.0 3 14.0 1 604.0 2 284.0 3 2

Applied in late May, late June and Mid-August. Mowed at 1.0 inch.

Rated June of year after application

“Newer” Sod Herbicides

Envoy - centipedegrassLontrel Confront DriveManor, BladeCorsair

“Newer” Sod Herbicides

Prompt 5LLabel changes for Kerb

Envoy (Valent)

SLN Georgia LabelCentipede sod farms onlySuppresses bermudagrassControls annual grassesNot for use on seed fieldsApply 3 wks after green-upDelay mowing 7 days before and after

Envoy - Bermuda Suppression

Two applications at 34.0 fl. oz./acreFour applications at 17.0 fl. oz./acre1st - 3 to 6 inch bermuda growth2nd, 3rd, 4th - 3 to 3 inch bermuda growthAlso controls most other annual grasses

Envoy

Clethodim0.94 lbs./gal. - EC17.0 to 34.0 fl. oz./acreAdd nonionic surfactant at 0.25% v/v

Sethoxydim (Vantage) - Centipedegrass

Controls annual grassesSuppresses bahiagrass and bermudagrassNo annual bluegrass controlNo nutsedge (nutgrass) control

Vantage - Centipedegrass

No COC neededEstablishedSeedling - 3 in. stolon growthDelay mowing 7 d before and after application

Vantage – Bahiagrass Suppression

2.25 pts./acreDelay mowing – 7 d before and after applicationRepeat application - 10 to 14 daysBahia must be actively-growing

Lontrel - DowAgrosciences

3.0 lb./gal. clopyralidHighly active on legumes and aster weedsAlso controls curly dock, smartweedRate 1/4 to 1.0 pt./acreHigh rate needed for smartweedWill not control dichondra (ponyfoot)

Turfgrass Tolerance to Lontrel

Turfgrass Tolerance to Lontrel

Kentucky Bluegrass T

Tall Fescue T

Bermudagrass T

Centipedegrass T

St. Augustinegrass T

Zoysiagrass T

Confront - DowAgrosciences

Triclopyr + clopyralid (2.25 + 0.75 lbs./gal.)Amine formulationActive on wide range of broadleaf weedsClopyralid highly active on asters and legumesTriclopyr controls chickweeds, henbit, mat

lippia, lambsquarters, Va. Pepperweed, shepherdspurse

Turfgrass Tolerance to Confront

Turfgrass Tolerance to Confront

Kentucky Bluegrass T

Tall Fescue T

Bermudagrass I (avoid summer, greenup)

Centipedegrass T

St. Augustinegrass S

Zoysiagrass T

Confront

Use 1.0 to 2.0 pts./acreUse on healthy, well established turfDelay reseeding for 3 weeksMow seedling turf 2 to 3 times before

applicationNeeds 6 hour rain-free period

Drive - TopPro

Quinclorac 75 DFAdd crop oil concentrate (2.0 pts./acre)Labeled on tall fescue, Ky. Bluegrass,

zoysiagrass, bermudagrass DO NOT use on centipedegrass or St.

Augustinegrass

Drive - TopPro

May be used before or after sprigging zoysiagrass

Controls crabgrass (except smooth), white clover, hop clovers, speedwell, dollarweed

Torpedograss - requires 2 to 3 applicationsWill not control goosegrassUse with extreme caution near tomatoes, bell

peppers, etc.

Manor, Blade

Metsulfuron 60 DFExcellent option for ‘Pensacola’ bahiagrass and

broadleaf control in warm-season turfgrassesDo not use on bahiagrass Low rate - < 1.0 oz. product/acreUse only 0.25 to 0.5 oz/acre on centipedeUse with nonionic surfactant

Corsair - Riverdale

Chlorsulfuron 75%Used primarily for spot control of clumpy tall

fescue in bermuda, zoysia, centipede, St. Augustine, Ky. Bluegrass – works slowly

Avoid transition applications on centipede, zoysia, St. Augustine

Repeat application in 60 dAdd NIS at ¼ to 1/3 fl. oz./gallon of spray mix

Prompt - TopPro

Pre-mix of bentazon+atrazine (2.5 lbs./gal. each) Labeled for bermuda, centipede, St. Augustine,

zoysia (some injury to bermuda)Good option for yellow nutsedge, kyllinga,

globe sedge, and numerous broadleaf weedsMay be used 10 d after sprigging2.4 pts./acre, repeat 7 to 10 d later for sedges

Kerb – Rohm & Haas

Label expanded to include centipede, St. Augustine and zoysia

Perennial ryegrass removal – apply at 50% green-up growth stage

Poa annua control during winter monthsNeeds rainfall or irrigation event (0.25 in.)

within 24 to 48 hrs

At-Sprigging Options

Ronstar 2G - bermuda, zoysia, paspalumRonstar 50WSP - bermudaAtrazine - centipede, St. Augustine, zoysiaSimazine - centipede, St. Augustine, zoysia

Ronstar 2G and 50WSP - At Sprigging

2G - 100 to 150 lbs./acre50WSP - 4.0 to 6.0 lbs./acreApply immediately before or after spriggingPre-sprigging (1 day before sprigging slightly

safer than post-sprigging)Irrigate ASAP for best results

Atrazine and Simazine - At Sprigging

Centipede, St. Augustine, zoysiaAtrazine - labeled up to April 15Simazine - labeled up to June 1Do not apply within 30 days before liftingApply 2 days after lifting sod on old beds - FLApply 7 to 10 days after sprigging - FL

TOLERANCE OF NEWLY-SPRIGGED CENTIPEDEGRASS TO ATRAZINE AND SIMAZINE

CENTIPEDEGRASSGROUND COVER (%)

HERBICIDE QTS./ACREWKS AFTERSPRIGGING 15 WAT 21 WAT

ATRAZINE 1.0 0 24 39

2.0 0 30 47

1.0 0,3 20 37

SIMAZINE 1.0 0 30 45

2.0 0 26 50

1.0 0,3 25 43

NONE --- --- 12 151JOHNSON, 1976

The majority of herbicides used in turfgrasses for preemergence annual grass control are dinitroanilines and dithiopyr

DNA’sBarricadePendulum Surflan BalanTreflanDimension

Best used on established turf.

Mitotic inhibitors. Relatively immobile

in the soil Minimal use in sod

fields

DNA and Dimension root inhibition

pendimethalin on zoysiagrass Dimension on

bermudagrass

Surflan on St. Augustinegrass

Swollen, club shaped roots

Sedge Herbicides - Turfgrasses

Basagran T/O - yellow, annual sedgesManage - yellow, purple, annual sedgesMSMA/DSMA - yellow, purple, annual sedgesImage - yellow, purple, annual sedgesPennant - yellow, annual sedges2,4-D - yellow, very poor activity

UGA Turf Weed Science Web Page

www.georgiaturf.com

193 weed species30 popular articlesUGA turf weed science recommendationslinks to herbicide labels, MSDS

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can be downloadedPLEASE USE IT!!!!!!!!!!!!!!!!