Weed Management on Putting Greens by 3Lz963

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									Weed Management
on Putting Greens
   Dr. Tim R. Murphy
Extension Weed Specialist
  University of Georgia
         Griffin
       Problem Putting Green Weeds
•   Annual Bluegrass - annual and perennial
•   Goosegrass
•   Crabgrass
•   occasional broadleaf weeds
•   nutsedge(s)
           Bermudagrass Greens
• Preemergence crabgrass and goosegrass

  – Bensulide (Bensumec, Pre-San, Betasan
  – Dithiopyr (Dimension)
  – Bensulide + oxadiazon (Scotts Goosegrass/Crabgrass
                             Control)
          Bermudagrass Greens
• Postemergence crabgrass and goosegrass

  – Diclofop (Illoxan), goosegrass only
  – MSMA/DSMA - low rates, repeat applications, very
    risky, avoid air temperatures > 85 F.
           Bermudagrass Greens
• Preemergence annual bluegrass control
  – Pronamide (Kerb) , apply 60 to 90 days before
    overseeding, activated charcoal is used when
    applications made < 90 days before overseeding
  – Fenarimol (Rubigan), apply 2 to 3 applications, last
    application 14 days before overseeding perennial
    ryegrass (30 days on P. trivialis), apply low rate in
    Jan.-Feb, for extended control
       Creeping Bentgrass Greens
• Preemergence crabgrass and goosegrass

  – Bensulide (Bensumec, Pre-San, Betasan
  – Dithiopyr (Dimension)
  – Bensulide + oxadiazon (Scotts Goosegrass/Crabgrass
                             Control)
         Creeping Bentgrass Greens
• Postemergence crabgrass and goosegrass

  –   No herbicides labeled for this use
  –   Low tolerance of creeping bentgrass
  –   MSMA/DSMA - very risky
  –   Acclaim Extra - too injurious
       Creeping Bentgrass Greens
• Annual bluegrass control
• Paclobutrazol (Scotts TGR, Trimmit)
     • a plant growth regulator that inhibits gibberellin
       biosynthesis
     • Poa more sensitive than bentgrass
     • apply in spring after bentgrass growth has resumed
     • works slowly, repeat applications needed
     • fall + spring applications needed for P. annua var. reptans
 Perennial Poa Treatments (Johnson and Murphy,
                      1995)

• TGR applied Oct. 1 + Nov 12 fb Mar 15 + May 1
  for 2 yr suppressed Poa 28% 4 MAT
• TGR at 0.5 + 0.25 fb 0.5 + 0.25 lbs. Ai/acre
• Cutless at same dates and rates suppressed Poa
  6% 4 MAT
 Perennial Poa Treatments (Johnson and Murphy,
                     1996)
Date     TGR       Cutless
mid-Mar 0.5        0.5
mid-Apr 0.5        0.5
mid-May 0.25       0.25
Oct 1    0.38      0.38
Nov 1    0.38      0.38
Dec 1    0.25      0.25
Perennial Poa Suppression
                             TGR    Cutless
                    80
                    70

    % Suppression   60
                    50
                    40
                    30
                    20
                    10
                     0
                         1     21          82   103
                                    DALT
Maximum Bentgrass Injury
                                           TGR
   Dec - 6d


 Nov - 11d


  Oct - 13d


  May - 7d


  Apr - 9d


 Mar - 12d

              0   5   10     15       20   25    30
                           % Injury

								
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