Chapter 7b. Turfgrass pest management- weed control by 5vx06o8


									 Turfgrass Management
           Alanna L. Neely

Chapter 7B Turfgrass Pest Management –
              Weed Control
 Sustaining a turf of acceptable quality
  usually means controlling weed species
  whose presence significantly reduces turf
 Besides conducting a cultural program
  that favors vigorous, healthy turfgrass
  growth, it is sometimes necessary to
  institute measures for directly controlling
  potential or actual weed invaders. This
  frequently involves the selection and
  application of appropriate herbicides.
 Weeds: types and species that occur in

 Herbicides: types and uses for weed
 Definition:
  ________________- those species that may
  be a weed under a specific set of
  circumstances, and a desirable (turfgrass)
  species under another (i.e., tall fescue,
  creeping bentgrass, Bermuda grass).
 ______ _____- those species that are always
  classed as weeds, regardless of
 Old sayings:
 Botanical weed types- _____, _____, _____.
 Annuals _________________________.
 Winter annuals germinate in the late-summer/
  early fall and die the following summer;
  examples: annual bluegrass, common
  chickweed, and henbit.
 Summer annuals germinate in spring and die
  with the first hard frost in fall; examples:
  knotweed, spurge, and crabgrass.
 Biennials ________________________.
 Perennials _______________________.
   Simple perennials are propagated by
    seed; examples: dandelion and
   Creeping perennials can reproduce by
 Functional weed types -
 _____ _____- can be controlled with
 ______ _____ - generally cannot be controlled
  with postemergence herbicides (phenoxy,
  picolinic and benzoic acids) applied to the
  foliage; however, some annual broadleaf
  weeds may be controlled with some of the
  same preemergence herbicides used for
            Weed Species:
               Annual Grasses:

                 Yellow foxtail   Annual bluegrass

               Fall Panicum       Goosegrass
             Perennial grasses:

                    Bermudagrass             Tall Fescue




                   Broadleaf weeds:

                   Broadleaf plantain        Buckhorn plantain

Common chickweed   Mouse-ear chickweed         Black medic


Curled dock               Red sorrel

Ground ivy       Henbit

Yarrow                         White clover

Yellow wood sorrel             Knotweed

Prostrate spurge                                        Carpetweed

        Round-leaved mallow

                                           Wild onion/garlic
 Types:
   A. Preemergence vs. postemergence
     Preemergence herbicides are applied _____ to
      the emergence of target weed species; some are
      effective with early post applications.
     Postemergence herbicides are applied _____
      emergence of the target weed species;
      application prior to emergence are usually
 Foliar vs. soil applied
   Foliar- applied herbicides are applied _____
   Soil- applied herbicides are applied _______
 Contact vs. systemic
   _____ _____ are not translocated within the plant; they
    work at the locations of immediate contact with the
    target weeds.
   ______ _____- are translocated within the plant to the
    site (s) of action; excessive rates must be avoided as
    they might result in less effective, contact action.
 Selective vs. nonselective
   ______ _______- selectively kill target species while
    not adversely affecting nontarget (turfgrass) species,
    provided they are applied at the proper rate and under
    the proper conditions.
   _______ ______- are used either for total vegetation
    control of for weed species for which no selective
    herbicides are available.
 Annual grass control:
   Preemergence herbicides include DCPA
    (Dacthal), bensulide (Betasan), Benefin
    (Balan), oxadiazon (Ronstar), and
    pendamethalin (pre-M).
   Postemergence herbicides used to refer to
    several organic arsenicals (MSMS, DSMA)
    which had to be applied several times at 7-
    10 day intervals; now Acclaim (fenoxyprop-
    ethly) and Drive (quinclorac) can be used
    with greater efficacy and safety.
 Perennial grass control:
   Roundup (glyphosate) and Finale (glufosinate)
    are the principal materials used as a spot
    treatment (directed spray of for total vegetation
   An evolving series of sulfonyl ureas, including
    Corsair (chlorsulfuron) and Certainty
    (sulfosulfuron), can be used for selectively
    controlling selected perennial grasses in some
    turfgrass communities.
   A new herbicide, mesotrione, has been
    successfully for selectivity controlling creeping
    bentgrass and nimblewill in Kentucky
    bluegrass turf.
 Broadleaf weed control:
   Old standard: 2, 4-D +MCPP + dicamba for
    broad-spectrum control with bromoxynil for
    BLW control in seedling turf.
   Added: 2, 4-D + Dichloroprop for tough
   New add: tryclopyr, or a combination of
    triclopry and clopyralid, in combination with
    2, 4-D for broad-spectrum control.
 Weeds, including botanical and functional
  types, and examples of weed species
  occurring in turf.
 Herbicides, including types:
     A. preemergence vs. postemergence
     B. foliar vs. soil applied
     C. contact vs. systemic
     D. selective vs. nonselective
 Controlling weeds with herbicides:
   A. annual grasses
   B. perennial grasses
   C. broadleaf weeds
     Closing Statement

 As in any other facet of turfgrass
  management, turfgrass weed control
  often involves the intelligent use of the
  available tools for accomplishing cultural
  objectives. In this arena the tools are
  called herbicides. When used properly,
  they can provide very satisfactory results;
  used improperly, they can create more
  problems than they solve.

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