Weed Control in Sod Production Fields Tim R. Murphy The University of Georgia Weed Problems in Sod Intensive irrigation and fertility effects Effect of herbicides on sod Row crop weeds Common bermudagrass control Row crop vs. turf herbicides – Same ai and formulation Cultural Control Avoid over-irrigation Install drainage if needed Properly mow on schedule – Will control most tall-growing broadleaf weeds Maintain pH and fertility Control insects and diseases Know 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 % Control 53 DAT 80 70 60 50 40 30 20 10 0 116 DAT 80 75 58 0 2 qts 0 5 qts 0 10 qts Roundup Rate/Acre DAT = Days after Treatment % Control - 1 YR Bermuda Control with Roundup – 1 yr. 100 90 80 70 60 50 40 30 20 10 0 99 65 56 4qt/2X 2qt/3X Rate Qt/Acre / No. of Apps. 2qt/2X Bermudagrass Control with Roundup (averaged across Tifway, Tifgreen, Tifdwarf, Ormond) Rate (qt.acre) Applications 2 2.0 3 2.0 2 3.0 3 3.0 1 4.0 2 4.0 3 4.0 % Bermuda Regrowth 47 1 26 1 60 28 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 - centipedegrass Lontrel Confront Drive Manor, Blade Corsair “Newer” Sod Herbicides Prompt 5L Label changes for Kerb Envoy (Valent) SLN Georgia Label Centipede sod farms only Suppresses bermudagrass Controls annual grasses Not for use on seed fields Apply 3 wks after green-up Delay mowing 7 days before and after Envoy - Bermuda Suppression Two applications at 34.0 fl. oz./acre Four applications at 17.0 fl. oz./acre 1st - 3 to 6 inch bermuda growth 2nd, 3rd, 4th - 3 to 3 inch bermuda growth Also controls most other annual grasses Envoy Clethodim 0.94 lbs./gal. - EC 17.0 to 34.0 fl. oz./acre Add nonionic surfactant at 0.25% v/v Sethoxydim (Vantage) - Centipedegrass Controls annual grasses Suppresses bahiagrass and bermudagrass No annual bluegrass control No nutsedge (nutgrass) control Vantage - Centipedegrass No COC needed Established Seedling - 3 in. stolon growth Delay mowing 7 d before and after application Vantage – Bahiagrass Suppression 2.25 pts./acre Delay mowing – 7 d before and after application Repeat application - 10 to 14 days Bahia must be actively-growing Lontrel - DowAgrosciences 3.0 lb./gal. clopyralid Highly active on legumes and aster weeds Also controls curly dock, smartweed Rate 1/4 to 1.0 pt./acre High rate needed for smartweed Will 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 formulation Active on wide range of broadleaf weeds Clopyralid highly active on asters and legumes Triclopyr controls chickweeds, henbit, mat lippia, lambsquarters, Va. Pepperweed, shepherdspurse Turfgrass Tolerance to Confront Turfgrass Tolerance to Confront Kentucky Bluegrass T Tall Fescue T Bermudagrass Centipedegrass I (avoid summer, greenup) T St. Augustinegrass S Zoysiagrass T Confront Use 1.0 to 2.0 pts./acre Use on healthy, well established turf Delay reseeding for 3 weeks Mow seedling turf 2 to 3 times before application Needs 6 hour rain-free period Drive - TopPro Quinclorac 75 DF Add 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 applications Will not control goosegrass Use with extreme caution near tomatoes, bell peppers, etc. Manor, Blade Metsulfuron 60 DF Excellent option for ‘Pensacola’ bahiagrass and broadleaf control in warm-season turfgrasses Do not use on bahiagrass Low rate - < 1.0 oz. product/acre Use only 0.25 to 0.5 oz/acre on centipede Use 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 d Add 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 weeds May be used 10 d after sprigging 2.4 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 months Needs rainfall or irrigation event (0.25 in.) within 24 to 48 hrs At-Sprigging Options Ronstar 2G - bermuda, zoysia, paspalum Ronstar 50WSP - bermuda Atrazine - centipede, St. Augustine, zoysia Simazine - centipede, St. Augustine, zoysia Ronstar 2G and 50WSP - At Sprigging 2G - 100 to 150 lbs./acre 50WSP - 4.0 to 6.0 lbs./acre Apply immediately before or after sprigging Pre-sprigging (1 day before sprigging slightly safer than post-sprigging) Irrigate ASAP for best results Atrazine and Simazine - At Sprigging Centipede, St. Augustine, zoysia Atrazine - labeled up to April 15 Simazine - labeled up to June 1 Do not apply within 30 days before lifting Apply 2 days after lifting sod on old beds - FL Apply 7 to 10 days after sprigging - FL TOLERANCE OF NEWLY-SPRIGGED CENTIPEDEGRASS TO ATRAZINE AND SIMAZINE CENTIPEDEGRASS GROUND COVER (%) WKS AFTER HERBICIDE QTS./ACRE SPRIGGING ATRAZINE 1.0 0 2.0 0 1.0 0,3 SIMAZINE 1.0 0 2.0 0 1.0 0,3 NONE 1 JOHNSON, 1976 --- --- 15 WAT 24 30 20 30 26 25 21 WAT 39 47 37 45 50 43 12 15 The majority of herbicides used in turfgrasses for preemergence annual grass control are dinitroanilines and dithiopyr DNA’s Barricade Pendulum Surflan Balan Treflan Dimension 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 Surflan on St. Augustinegrass Swollen, club shaped roots Dimension on bermudagrass Sedge Herbicides - Turfgrasses Basagran T/O - yellow, annual sedges Manage - yellow, purple, annual sedges MSMA/DSMA - yellow, purple, annual sedges Image - yellow, purple, annual sedges Pennant - yellow, annual sedges 2,4-D - yellow, very poor activity UGA Turf Weed Science Web Page www.georgiaturf.com 193 weed species 30 popular articles UGA turf weed science recommendations links to herbicide labels, MSDS UGA Weed Science Web Site www.gaweed.com Covers all crops including turf and ornamentals Weed Identification Currently has over 40 PowerPoint slide sets that can be downloaded PLEASE USE IT!!!!!!!!!!!!!!!!