Weed management in the landscape

Travis Gannon, PhD

12-9-11

www.turffiles.ncsu.edu

www.TurfFiles.ncsu.edu

Travis Gannon

919.513.4655

Travis_gannon@ncsu.edu

TurfFiles

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What is a Weed?

A plant growing where it is not wanted

66

The Nature of Weeds

• Opportunistic plants

• Adapted to “niches” within the environment

• Herbicides can eliminate the weed, but not the

environmental conditions that provided an

“opportunity” for that weed

A paradigm shift

weed control weed management

Weed Management

• Herbicides are effective means of control

• However . . .

– Elimination of the weed does not eliminate the

environmental condition that creates a competitive

advantage

– How heterogeneous are turfgrass environments?

– Current management practices assume

homogeneity

• Plant Competition:

– Light – most plants compete for this

– Nutrients

– H2O

– CO2

Weeds vs. Turf

Why Do We Have

Weed Problems? 1. Turfgrasses are non-native plants

2. Monocultures

3. Lack of sanitation

4. Cosmetic standards

Why Do We Have

Weed Problems?

• Turfgrasses are not native (depending on

where you are of course):

Growing non-native vegetation is always

difficult

Why Do We Have

Weed Problems?

• Ecology 101:

Natural Succession: Long term transition

of vegetation types to a condition of

stability.

Why Do We Have

Weed Problems?

• Monocultures – growth of a single

species

Monocultures tend to be man-made. In

turf, we force mother natures hand to

compete against us.

Why Do We Have

Weed Problems?

• Lack of Sanitation and Natural Movement

– People (shoes) and equipment (mowers, sprayers, tillage implements) movement from site to site spread weed seeds, tubers, bulbs, rhizomes, stolons, etc. Animals, wind and rain also spread weeds.

Inspect sod prior to purchase

Many problematic weeds are introduced

on container grown ornamentals

Perennial Ryegrass

(Lolium perenne)

Effect of Mowing Height on Large Crabgrass

Incidence

• 3.5 lbs Crabgrass/1000ft2 on March 7,

2007

• Mowing Heights initiated when soil

temperatures reached 55°F – Mowed

every 4 days thereafter

0.5” 1.0”

1.5” 2.0”

79

74

31

00

10

20

30

40

50

60

70

80

% C

ra

bg

ra

ss

1.0" 2.0" 3.0" 4.0"

Mowing Height

Effect of Mowing Height on Crabgrass

Incidence in Tall fescue

Data Collected: 09-13-07, LSD (P=0.05), Sandhills Research Station, Sodman 90/10

(mixture w/ bluegrass)

a a

b

c

3” 4”

1” 2”

1” 2”

3” 4”

1”

Imprelis Herbicide developed by DuPont for selective weed

control in turf

Industrial vegetation management

Range and pasture

Specialty crops – rice, fruit, sugarcane

Row crop – corn, burndown

Labeled – mid-2010

Introduction

Objective #2: Determine the effect of simulated herbicide

drift into non-target areas.

• Aminocyclopyrachlor (AMCP) • Recently registered synthetic auxin herbicide

• Thought to possess more favorable environmental profile

• Highly active compound

• Widely used in cool-season turf

• Limited e-fate and off-target research available

Objective #2: Determine the effect of simulated herbicide

drift into non-target areas.

• Aminocyclopyrachlor (AMCP) • Recently registered synthetic auxin herbicide

• Thought to possess more favorable environmental profile

• Highly active compound

• Widely used in cool-season turf

• Limited e-fate and off-target research available

Implications

• x

Gannon - CS725 (pest. chem.) Gannon - CS725 (pest. chem.)

Dow Agro

Gannon - CS725 (pest. chem.) Gannon - CS725 (pest. chem.)

Other new products or

revised labels

• Bleacher

• Turf Safety:

– Ky. Bluegrass and centipedegrass most tolerant

– Tall fescue moderately tolerant

– Ryegrass, St. Augustinegrass, & fine fescue

have “tolerable” registration.

– Bentgrass, bermudagrass, zoysiagrass - low

tolerance,

– Turf injury increases with heat & drought.

• Rates: 4 to 8 oz/a (0.125 to 0.25 lb ai/a, 0.14

to 0.28 kg ai/ha) twice 2 to 3 weeks apart.

• Golf, sod, residential and commercial

properties,

Tenacity

• A new chemical class – Triketones

• Active ingredient – 40% Mesotrione

• Formulation – 4SC

• Signal word – Caution

• For Use by Professional Applicators

• Do not enter treated areas until spray has dried

34 Dicot and 11 Monocot Species on

Tenacity Label Including:

• Crabgrass spp.

• Goosegrass

• Nimblewill

• Bentgrass

• Oxalis

• Buckhorn plantain

• Clover spp.

• Speedwell

• Lawn burweed

• Dandelion spp.

• Canada thistle

• Yellow nutsedge

• Yellow foxtail

• Ground Ivy

This list will expand as research and commercial use find new species.

Tall Fescue

KY Bluegrass

Perennial Ryegrass

Centipedegrass

St Augustinegrass

Turfgrass Tolerance to Tenacity

Smooth and large Crabgrass (Digitaria spp.)

Nimblewill (Muhlenbergia schreberi)

BASF

Drive XLR8: Better control of 4 to 8 tillered crabgrass?

Use on tall fescue, zoysiagrass, bermudagrass, Ky.

bluegrass, seashore paspalum, ryegrass and

bentgrass fairways with good soil moisture conditions

Controls crabgrass, signalgrass, foxtail, clover, dandelion,

corn speedwell (no goosegrass control!)

Apply before 2nd tiller or to mature grasses (2 to 4 tillers not

recommended)

Rate: 0.5 gallon/A + 1.5 pt/A MSO for Drive XLR8 1.5SL

1 lb/A + 1.5 pt/A MSO for Drive 75DF

Q4 1.54L PBI-Gordon

Quinclorac + Sulfentrazone + 2,4-D amine + Dicamba

Cool season turf only

Rate: 7 to 8 pt/A on crab, signalgrass, foxtail, broadleaves

Apply to seedlings after 2nd or 3rd mowing or 28 days after

emergence

Spray 3 to 4 weeks after sodding, sprigging or plugging

Can seed 4 weeks after application

• Manufactured by:

– PBI/Gordon

• Active ingredients:

– Quinclorac (8.43%)

– Sulfentrazone (0.69%)

– 2,4-D (11.81%)

– Dicamba, (1.49%)

• Postemergent activity

• EPA reg. no. 2217-930

• Mode of action:

– Synthetic auxin/cellulose inhibitor

– PPO/Protox inhibitor

– Synthetic auxin

– Synthetic auxin

Q4 Plus

• Tolerant turf species

– Perennial ryegrass

– Kentucky bluegrass

– Annual bluegrass

− Rough bluegrass

− Fescue species

− Do not apply to solid fine fescue stand

Q4 Plus usage rates and sites

• Cool-season turf

– 7-8 pints/Acre

• May discolor fine fescue

• Bermudagrass

– 5-7 pints/Acre

• May discolor common

and hybrids

• Where to use

– Residential areas

– Recreational areas

– Golf courses

– Streets

– Athletic fields

– Right-of-ways

– Sod production

Q4 Plus

• Turf weeds controlled • Barnyardgrass

• Large crabgrass

• Smooth crabgrass

• Spurge

• Dollarweed

• Foxtails

•Mock-strawberry

•Henbit

•Yellow woodsorrel

•Purslane

•Carpetweed

•White clover

•Wild violet

•Ground ivy

•Common

chickweed

•Buckhorn plantain

•Broadleaf plantain

T-Zone 2.5L Triclopyr (8.4%) + sulfentrazone (0.73%) + 2,4-D (32%) + dicamba (2.4%)

•PBI/Gordon Corporation,

•Controls many tough weeds such as

Wild Violets,

Yellow Nutsedge suppression

Ground Ivy,

Oxalis

Black Medic

•All cool-season turfgrasses,

•Bermudagrass, zoysiagrass, &

bahiagrass.

Sulfentrazone + Quinclorac (75WG)

25% + 50%

FMC

Tolerant to bermudagrass, centipedegrass, zoysiagrass,

seashore paspalum, as well as tall fescue, Ky. bluegrass

and perennial ryegrass

Rate: 1 to 2 lb/A with no spray adjuvant needed

After treatment, wait 1 month to reseed, overseed or sprig

Establish sod for 3 months and wait 3 month before harvest

Controls crabgrass, 1-4 lf goosegrass, foxtail, yellow

nutsedge, kyllinga species and broadleaf weeds

Some pre activity

• Carfentrazone (3.9%) + Quinclorac (66.1%)

• 70WDG

• FMC Corp.,

• Residential, commercial lawns, athletic fields, sod farms

golf course fairways and roughs,

• Warm-season turf except St. Augustinegrass @ 12 to 18

oz/acre,

• Most cool-season turfgrasses at 8 to 12 oz/acre,

• Controls broadleaves, yellow nutsedge, crabgrass,

foxtail + others.

• Can be applied 1 day prior or 7 days after seeding.

• Metsulfuron (6%) + Sulfentrazone (60%) – 66WDG

• FMC Corp.,

• Residential, commercial lawns, athletic fields, sod farms

golf course fairways and roughs,

• Bermuda, zoysia, centipede, St. Augustine @ 6.5 to 10

oz/acre,

• Kentucky bluegrass & tall fescue at 3.25 to 6.5 oz/acre,

• Controls many broadleaves, wild garlic, yellow nutsedge,

sedge and kyllinga species, foxtail + others.

• Wait 1 month after applying to reseed or sprig and wait 6

to 8 weeks to overseed perennial ryegrass ; wait 3

months for sod establishment before applying

4-Speed 3L 2,4-D (38%) + MCPP (6.3%) + dicamba (2.5%) + pyraflufen (0.06%)

•Nufarm,

•Pyraflufen-ethyl = Octane

•Controls broadleaf weeds:

•Dandelion, Buckhorn plantain, Oxalis, Chickweed,

White clover + others.

•Golf course, cemeteries, parks, sports fields, lawns, sod,

others,

•Bahia, bluegrass, bermudagrass, fescue, ryegrass, and

zoysiagrass = 3 to 4 pts/acre,

•Bentgrass = 1.8 pts/acre.

4-Speed XT 2.9L 2,4-D (42%) + triclopyr (4.8%) + dicamba (3.5%) + pyraflufen (0.07%)

•Nufarm,

•Pyraflufen-ethyl = Octane

•Controls broadleaf weeds:

•Wild violets, Ground Ivy, Dandelion, Oxalis, Chickweed,

White clover + others.

•Golf course, cemeteries, parks, sports fields, lawns, sod,

others,

•Bahia, bluegrass, bermudagrass, fescue, ryegrass, and

zoysiagrass = 3 to 4 pts/acre,

•Bentgrass = 1.8 pts/acre,

expect slight yellowing for

about 1 week.

ProSedge

• Manage, Sedgehammer

• Manufactured by:

– Nufarm

• Active ingredient:

– Halosulfuron (75%)

• Mode of action

– Acetolactate synthase

(ALS) inhibitor

• Postemergent activity

• EPA reg. no. 228-702

Tolerant turf species

• Cool-season grasses

– Creeping bentgrass

– Kentucky bluegrass

– Fine fescue

– Tall fescue

– Perennial ryegrass

• Warm-season grasses

– Bahiagrass

– Bermudagrass

– Centipedegrass

– Seashore paspalum

– St. Augustinegrass

– Zoysiagrass

– Kikuyugrass

ProSedge

• Weed activity

– Control

• Yellow nutsedge

• Purple nutsedge

– Growth suppression

• Kyllinga

• Where to use

– Commercial and

residential turf

– Golf courses

– Roadsides

– Athletic fields

– Sod/Seed production

– Public recreational

areas

Usage specifications

and precautions • Usage rates

– 0.67–1.33 ounces product/Acre = 0.5-1.0 ounce a.i./Acre

• Include a non-ionic surfactant (0.25-0.5% v/v) for broadcast

applications

– A sequential application may be necessary 6-10 weeks for

control of mature sedge species

• Precautions – Do not apply to golf course putting greens

– Two day mowing buffer pre- and post application

– Four hour rainfree period following application

– Two week annual and perennial ryegrass overseeding buffer

Annual bluegrass control

Amicarbazone - 70% WDG Herbicide developed by Arysta LifeScience Corp.

Field corn, sugarcane

Preplant, PRE, E. POST

Turf registration – expected 2011???

Introduction

Post annual bluegrass control Golf course, seed/sod production, residential, parks,

sportsfields, roadsides

Warm-season tolerant turf:

Bahiagrass, bermudagrass, centipedegrass, seashore paspalum,

St Augustinegrass, zoysiagrass

Cool-season tolerant turf

Bentgrass, KY bluegrass, fine fescue, tall fescue, perennial

ryegrass

Introduction

Apr 24, 2008

Weed identification and control

www.TurfFiles.ncsu.edu

Poa annua L.

Annual Bluegrass

Poa annua L.

Annual Bluegrass

• Monocot

• Winter Annual and Perennial

• Key I.D. Features:

- general structure: ssp. annua is an upright, clump-forming, winter annual; ssp. reptans is a prostrate, clump-forming, perennial

- leaves: light green, folded in the bud, lack auricles, pointed membranous ligule, boat-shaped tip

- seedheads: open, greenish white pyramidal panicle; produced at low heights of cut

Annual bluegrass control

• Many preemergent herbicides are effective – In established turf

• Prograss – certified pesticide applicator

Digitaria ischaemum (L.) Scop.

Smooth Crabgrass

Digitaria ischaemum (L.) Scop.

Smooth Crabgrass

• Monocot

• Summer Annual

• Key I.D. Features:

- general structure: tufted, decumbent, summer annual to 60 cm, spreading

- leaves: few hairs at mouth only, membranous ligule

- seedheads: consist of 3-5 spikes clustered at the top of stems; hairs on spikelets

- root system: fibrous roots, does not root at nodes

Crabgrass control

• Many preemergent herbicides are effective – In established turf

• Acclaim Extra

• Drive or Drive XLR8

• Fusilade

• Solitare

• SquareOne

Paspalum dilatatum Poir.

Dallisgrass

Paspalum dilatatum Poir.

Dallisgrass

• Monocot

• Complex Perennial

• Key I.D. Features:

- general structure: a coarse-textured, clump- forming grass plant with thick rhizomes

- leaves: rolled, tall and membranous ligule, auricles absent, margins hairy, collar hairy

- seedheads: divided spike; 3 to 7 spikelets covered in silky soft hairs with heavy black seeds

- root system: fibrous roots and shallow rhizomes

Dallisgrass control

• Glyphosate spot treatments

Eleusine indica (L.) Gaertn.

Goosegrass

Eleusine indica (L.) Gaertn.

Goosegrass

• Monocot

• Summer Annual

• Key I.D. Features:

- general structure: erect grass that bends at the nodes, silver crown area

- leaves: folded, membranous, and divided at the center, contains hairs only at the base of the leaf

- seedheads: contain 3-7 spikes, seeds are attached in a zipper appearance on the spike

- root system: fibrous

Goosegrass control

• Many preemergent herbicides are effective – In established turf

• Acclaim Extra

• Fusilade

Cynodon dactylon (L.) Pers.

Common Bermudagrass

Cynodon dactylon (L.) Pers.

Common Bermudagrass • Monocot

• Complex Perennial

• Key I.D. Features:

- general structure: a mat-forming, wiry grass with spreading rhizomes and stolons

- leaves: gray-green to bluish green, rolled in the bud, auricles absent, ligule is a row of hairs, blades are short and narrow

- seedheads: spikes at terminal end of stems

- root system: abundant, flat stolons, rhizomes form a dense turf

Bermudagrass control

• Acclaim Extra – Alone or tank-mixed with Turflon Ester

• Fusilade

Stellaria media (L.) Vill.

Common Chickweed

Stellaria media (L.) Vill.

Common Chickweed • Dicot

• Winter Annual

• Key I.D. Features:

- general structure: dense, patch-forming plant, can produce one or two generations each year

- leaves: light green, sparse hairs, opposite, elliptic to oval, pointed at the apex

- stems: prostrate, branching, smooth

- flowers: white with 5 deeply lobed petals

- fruit: oval, 1-celled capsules

- root system: fibrous and shallow

Cerastium vulgatum L.

Mouseear Chickweed

Cerastium vulgatum L.

Mouseear Chickweed

• Dicot

• Simple Perennial

• Key I.D. Features:

- general structure: dense, mat-forming plant with hairy stems and leaves

- leaves: opposite, dark green above, elliptic, margins are entire, densely covered with hairs

- stems: 2 rows of dense hairs, root at nodes

- flowers: white, 5 deeply lobed petals

- fruit: oval, 1-celled capsules

- root system: fibrous

Lamium amplexicaule L.

Henbit

Lamium amplexicaule L.

Henbit

• Dicot

• Winter Annual

• Key I.D. Features:

– general structure: a prostrate stemmed plant branching at the base with whorled leaves

– leaves: rounded to heart-shaped, rounded teeth, palmately veined, upper leaves surround the stem

– stems: square, green to purple, prostrate

– flowers: showy whorls pink to purple in color

– root system: fibrous roots; can root at stem nodes

Trifolium repens L.

White Clover

Trifolium repens L.

White Clover • Dicot

• Complex Perennial

• Key I.D. Features:

– general structure: mat-forming legume with low creeping stolons

– leaves: trifoliate; leaflets are oval shaped with a light green chevron (V-shaped) near the base

– stems: prostrate, root at the nodes

– flowers: white or pink rounded heads

– root system: stolons that root at the nodes

Allium vineale L.

Wild Garlic

Allium vineale L.

Wild Garlic • Monocot

• Simple Perennial

• Key I.D. Features:

- general structure: unbranched, circular, erect leaves emerging from underground bulbs

- leaves: linear, smooth, round, and hollow; have a garlic scent when crushed

- flowering stems: solid, unbranched, smooth, leafless, erect

- flowers: bulblets at the ends of hollow stems that may develop tail-like green leaves

- root system: fibrous roots from underground

bulbs

Oxalis stricta L.

Yellow woodsorrel

Oxalis stricta L.

Yellow woodsorrel

• Dicot

• Complex Perennial

• Key I.D. Features:

– general structure: a low growing herb that spreads by seed and rhizomes

– leaves: trifoliate (three heart-shaped leaflets), have long petioles

– flowers: yellow, arise in clusters, 5 petals

– fruit: cylindrical, pointed, hairy capsules that explosively eject seeds

– root system: rhizomes and fibrous roots

Taraxacum officinale Weber ex

Wiggers

Common dandelion

Taraxacum officinale Weber ex

Wiggers

Common dandelion • Dicot

• Simple Perennial

• Key I.D. Features: - general structure: yellow flowers borne on

leafless stalks emanating from a basal rosette, milky sap

- leaves: arranged in a basal rosette, margins deeply lobed, lobes point to the base

- flowers: bright yellow, consist of ray flowers

- seedheads: globe-like, grayish white, parachutes

- root system: thick, fleshy taproot that may be branched

Hypochoeris radicata L.

Cat’s ear dandelion

Hypochoeris radicata L.

Cat’s ear dandelion

• Dicot

• Simple Perennial

• Key I.D. Structures :

- general structure: basal rosette of leaves with long, erect, branched stalks, milky sap

- leaves: hairy, irregular to rounded lobes

- stems: tall, branched, mostly leafless

- flowers: bright yellow, consist of ray flowers

- seedheads: globe-like, grayish white parachutes

- root system: thick, long taproot that may be branched

Plantago major

Broadleaf plantain

Plantago major

Broadleaf plantain • Dicot

• Simple Perennial

• Key I.D. Features:

- general structure: perennial from a basal

- leaves: rosette with broad oval leaves smooth or slightly hairy, oval to elliptic, waxy surface, parallel veins, margins sometimes wavy

- flowers: produced on unbranched stalks (scapes) that arise from the rosette

- root system: taproot with fibrous roots

Plantago lanceolata

Buckhorn plantain

Plantago lanceolata

Buckhorn plantain • Dicot

• Simple Perennial

• Key I.D. Features:

- general structure: perennial from a basal rosette with lanceolate leaves

- leaves: smooth or slightly hairy, linear to lanceolate, parallel veins

- seedheads: produced on unbranched stalks (scapes) that arise from the rosette

- root system: taproot with fibrous roots

Annual and perennial broadleaf

weed control

• Coolpower

• Escalade 2

• Horsepower

• Speedzone

• Trimec Classic

• Triplet

• TZone

Sedge characteristics

•Monocots

•Triangular stems

(unlike grasses)

•Stems are solid

•Thrive in wet or

poorly drained soils

Cyperus esculentus L.

Yellow nutsedge

• Monocot

• Complex Perennial

• Key I.D. Features:

- general structure: a grass-like plant with yellowish green foliage

- leaves: narrow, yellow-green, pointed blade tips

- flowers: yellowish to brownish spikelets in clusters

- root system: presence of rhizomes and chestnut/white tubers

Cyperus esculentus L.

Yellow nutsedge

Cyperus rotundus L.

Purple nutsedge

Cyperus rotundus L.

Purple nutsedge • Monocot

• Complex Perennial

• Key I.D. Features:

- general structure: an erect, persistent perennial that may reach 2.5 ft in height

- leaves: wide, dark green, blunt blade tips

- stems: erect, unbranched, 3-angled flowering stems

- flowers: purplish spikelets in clusters

- fruit: purplish brown, three-angled achene

- root system: rhizomes with chains of charcoal tubers

Cyperus compressus L.

Annual sedge

Cyperus compressus L.

Annual sedge • Monocot

• Summer annual

• Key I.D. Features:

- general structure: bunch-type growth habit that typically emerges later in summer than other sedges

- seedheads: clusters of flat, green spikes on stalks

- root system: fibrous root system, no tubers

Kyllinga spp.

Kyllinga

Kyllinga spp.

Kyllinga

• Monocot

• Complex Perennial

• Key I.D. Features:

- general structure: mat-forming perennial sedge that gives off fruity fragrance when cut

- leaves: dark green in color, shiny, taper to a sharp point; no hairs, ridge along midvein

- seedheads: simple single roundish congested head with three bracts below

- root system: red to purple rhizomes

Sedge control

• Dismiss

• Prosedge

• Q4