Fall and Winter Weed Management

Options in Centipedegrass

L. S. Warren (09-17-14)

What are advantages to early weed

control? (Oct-Dec vs Jan-Mar)

Can control before desired turf gets thinned out

Less herbicide usually needed for control of younger plants

(save money)

Herbicide may not control mature plants no matter the rate

(Henbit very hard to control in winter and spring)

Herbicides do not kill weed seeds (you may kill the parent

plant, but offspring will be unaffected)

Oct 19, 2011

Mar 20, 2012

Annual Bluegrass Control in Common Bermuda

Spray Nov Photo Feb

Turf Weed Management Topics

Oct-Dec Weed Control Options (POST)

Annual bluegrass

Numerous broadleaf weeds

Wild garlic

Jan-Mar Weed Control Options (POST / PRE)

Annual bluegrass

Numerous broadleaf weeds

Wild garlic

Crabgrass, goosegrass – PRE

OCTOBER - DECEMBER

Weed Management Options

PRE and POST Weed Management

Strategies for Poa annua Control

Kerb SC T&O

• 1.25 to 2.5 pt pre to pre tiller / 2.5 to 3.5 pt seedhead

• Apply September 15 through February 1

• Do not overseed for 90 days

• Tolerance in bermuda, zoysia, centipede and St. Aug

• Product is mobile if heavy rain or irrigation!

• Not for home use

Poa annua and Winter Annual

Broadleaf Weed Control

• atrazine (AAtrex and other trade names)

1 to 2 lb ai/acre Nov 15 – Dec 31

Centipede, St. Augustine, bermuda, zoysia

• simazine (Princep – several formulations)

1 to 2 lb ai/acre Nov 15 – Dec 15

Centipede, St. Augustine, bermuda, zoysia

Poa annua and Winter Annual

Broadleaf Weed Control

atrazine and simazine control many common

winter annual broadleaf weeds such as:

Common chickweed

Henbit

Corn speedwell

Lawn burweed

Hop clover

Many other broadleaf weeds listed on their labels.

Check

Little barley, annual

bluegrass, henbit, Brazilian

catsear, Carolina geranium,

mouseear chickweed, corn

speedwell

Atrazine 2 qt/acre

Photos Apr 11, 2005

Princep 1 lb ai /A

AAtrex 1 lb ai /A

Roundup Pro 1 lb ai /A

Treated Dec 22, 2003 Photo Feb 5, 2004

Post Annual Bluegrass Control in

Centipedegrass

Sulfonylurea Herbicide Highlights

Can basically apply anytime in fall, late winter, spring

when temperatures are mild to warm and poa

actively growing

Control various common broadleaf weeds including

henbit

TranXit (25DF): rimsulfuron; not labeled for home

use; apply 1 oz/A; use nonionic surfactant

Tranxit + NIS (not for home use)

1 oz/A + 0.25%

Applied Nov

Photo Apr

TranXit + NIS

1 oz/A + 0.25%

Applied Jan 13

Photo Apr 7, 2004

Post Annual Bluegrass Control in

Centipedegrass

Sulfonylurea Herbicide Highlights

Certainty (75WG): sulfosulfuron

Home use label; apply 1.25 to 2 oz/A to pre-tillered

poa for best chance for control – does not provide

consistent long-term control compared to TranXit

Use a nonionic surfactant

Cool Season Perennial and Winter Annual

Broadleaf Weeds, Wild Garlic

(October – December)

Best time for control: less herbicide usually needed

Winter Annual Seedlings

Actively growing, seedling stage, few leaves

Cool Season Perennials

Actively growing, juvenile stage, recent new growth

Henbit Control averaged over 1997 - 2007

50

39 3843 42

0

20

40

60

80

100

% C

on

tro

l

Millenium Ultra 2 1-1.25 qt

Escalade 2 1-1.5 qt

Trimec Classic 1.5-1.75 qt

Confront 1-2 pt

Coolpower 1-1.5 qt

Rates are product per acre, averaged across formulations, locations, years.

Trimec Classic 3.5 pt/A: Apr 11, 2005 (4 WAT)

Check

Escalade 2 4EC 3 pt/A

Applied 10-22-09

Photo 11-17-09

Postemergence Henbit Control in

Centipedegrass

- Henbit easily controlled with herbicides

containing…

- sulfonylureas such as Manor, Celsius, Blindside

and Corsair

- triazines such as atrazine and simazine

Postemergence Broadleaf Weed

Herbicides Labeled for Centipedegrass

Celsius WG (68WG)

Thiencarbazone + iodosulfuron + dicamba

Home use label

Overseed ryegrass 2 wk after application

2.5 oz/A applied 3 times, 2-4 wks apart

3.7 oz/A applied 2 times, 2-4 wks apart

4.9 fb 2.5 oz/A, 2-4 wks apart

Use nonionic surfactant or methylated seed oil

Postemergence Broadleaf Weed

Herbicides Labeled for Centipedegrass

Trimec Southern (3.06 lb/gal)

2,4-D amine + mcpp + dicamba

Don’t spray below 50F or during spring transition

1 to 1.5 pt/A; home use label; no adjuvant needed

Speed Zone Southern (0.81EC)

Carfentrazone + 2,4-D ester + mcpp + dicamba

2 to 4 pt/A; home use label; no adjuvant needed

Postemergence Broadleaf Weed

Herbicides Labeled for Centipedegrass

Battleship III (3.41L)

MCPA amine + fluroxypyr ester + triclopyr amine

Use up to 3 pt/A on 0.5 inch ht. or higher turf

Home use label; no adjuvant needed

Defendor (0.42SC)

Florasulam; home use label; 4 fl oz/A

Use nonionic surfactant; controls chickweed, clover,

plantains, dandelion, ground ivy, woodsorrel, betony

Postemergence Broadleaf Weed

Herbicides Labeled for Centipedegrass

Dismiss (4SC)

Sulfentrazone; home use label; 0.75 pt/A

No adjuvant needed; controls clover, dandelion,

henbit, chickweed, geranium, bittercress, burweed

Blindside (66WG)

Sulfentrazone + metsulfuron; home use label

Up to 10 oz/A on centipede

No adjuvant needed

Postemergence Broadleaf Weed

Herbicides Labeled for Centipedegrass

Lontrel (3EC)

Clopyralid; not for home use; 1 pt/A

No adjuvant needed; controls burweed, speedwell and

cudweed species, vetch, clover, dandelion

Confront (3SL)

Clopyralid + triclopyr; not for home use; 1 to 2 pt/A

No adjuvant needed; controls plantain and chickweed

species, henbit, wild violet

Wild Garlic Control in Centipedegrass

Image 70DG - slightly sensitive

8.6 to 11.4 oz/A + nonionic surfactant

Do not apply within 6 wk of spring transition

Manor - slightly sensitive

0.5 oz/acre + nonionic surfactant

Corsair - slightly sensitive

2.76 to 5.33 oz/acre + nonionic surfactant

Temporary delay in spring greenup may occur

Check

Centipede

Corsair + NIS

4 oz/acre + 0.25%

Applied Nov 2010

Photo Mar 19, 2011

Centipede greenup reduced

25% on Apr 21

JANUARY

- MARCH

Weed Management

Options

POST Weed Management Strategies

for Poa annua Control

Kerb SC T&O

• 2.5 to 3.5 pt seedhead

• Apply September 15 through February 1

• Do not overseed for 90 days

• Tolerance in bermuda, zoysia, centipede and St. Aug

• Product is mobile if heavy rain or irrigation!

• Not for home use

Post Annual Bluegrass Control in

Centipedegrass

Sulfonylurea Herbicide Highlights

TranXit at 1 oz/A still effective if poa actively

growing

Certainty not effective on tillered poa

Poa annua Control and Seedhead

Suppression in Overseeded Bermuda

Xonerate (70WG): amicarbazone

Xonerate is tolerant to many established (at least 6

months) cool and warm season turf species, BUT

its main niche is bermudagrass overseeded with

perennial ryegrass.

Warm season: 3 to 10 oz/A at 2 to 3 wk intervals

not to exceed 10 oz/A – EXPENSIVE!!!!!

Check

Xonerate - 4 oz/acre

Feb 23 and Mar 7

Overseeded Oct 13

Cool Season Perennial and Winter Annual

Broadleaf Weeds, Wild Garlic

(January – March)

All products discussed for October - December

section may be used

May need higher rates on larger weeds

Warm season turf greenup may be affected

(delayed)

Preemergence Crabgrass and

Goosegrass Control in Centipedegrass

Lots of choices: Apply January through early March

Usually advantageous to split applications at 6 to 8

wk intervals if using…

…DNA herbicides (benefin, oryzalin, prodiamine,

pendimethalin)

…dithiopyr (Dimension)

…indaziflam (Specticle)

PRE Crabgrass and Goosegrass

Herbicide Families

Dinitroanilines (DNA’s) and rates lb ai/A

Balan, Surflan, Team Pro, Pendulum, Barricade, Echelon

3 3 3 2 to 3 0.75 0.75

Have PRE and early POST activity (be careful here!!)

Will control crabgrass and goosegrass in the one leaf stage if watered in immediately – granules iffy when post!!

Are root inhibitor herbicides

Not ideal for athletic fields or heavy traffic areas

PRE Crabgrass and Goosegrass

Herbicide Families

Pyridines

Dithiopyr (Dimension, Dimension Ultra WSP)

0.5 lb ai/A

Are not DNA herbicides but have the same mode of action (excellent crabgrass, good on goosegrass)

Somewhat volatile – works better pre as a granular

Controls crab & goose up to 3-4 lvs – granules iffy

Not ideal for athletic fields due to root inhibition

Clubbed roots

Normal roots

St. Aug. sprayed in spring 2001 with Barricade 65WG – photo Oct 29

Specticle Flo (0.622F) - indaziflam

Acceptable Centipede Turf Sites

• Golf course turf – not putting greens

• Sports fields

• Home and commercial lawns

• Parks

• Cemeteries

• Not for sod farms

Specticle Flo

• Use up to 6 fl oz/A on established ‘TifBlair’

centipede – may temporarily inhibit stolon rooting

• Broadleaf spectrum similar to DNA & triazine

herbicides – doesn’t stain like DNAs

• Cellulose biosynthesis inhibitor (alkylazine

herbicide family)

• Long soil residual (overseeding concerns) – 10 to

12 month delay if 6 fl oz/A or > used

Specticle Flo

Restrictions and Comments

• Stay 25’ away from bodies of water

• Stay 15’ away from susceptible turf species

• Sprigs: spray 16 months later sprigging

• Sod: do not sod using Specticle Flo

Specticle 20WSP 2.5 oz/A

Applied Apr 22, 2010; photo 10-28-10

Sandhills Station

Nontreated

10-28-10

Sandhills Station

Pre Smooth Crabgrass Control in Common

Bermuda Using Standard Labeled Herbicides

0

20

40

60

80

100

10-Sep

Barricade 65WG

0.75 lb aiABarricade 4F

0.75 lb ai/ABensumec 4L

10 lb ai/ADimension 2EW

0.5 lb ai/AEchelon 4SC

1.125 lb ai/AQP Oryzalin 4 Pro

3 lb ai/APendulum Aquacap

3 lb ai/ASpecticle Flo

6 fl oz/ACheck

% C

ontr

ol

2014: Lake Wheeler Turf Field Lab

7 lsd p=.05

Applied Feb 24

Pre Goosegrass Control in Common Bermuda Using

Specticle 20WP, Tower 6L & Ronstar Formulations

0

20

40

60

80

100

5-May 7-Jul 7-Sep

Ronstar 38 Flo

2.5 qt/ARonstar 38 Flo

3.78 qt/ASpecticle 1.25 oz/A

Specticle 2.5 oz/A

Tower 1 qt/A

Tower fb Tower

Mar-Apr 1 qt fb 1 qt/APend. Aquacap 3.8CS

3.16 qt/ARonstar 2G 150 lb/A

Check

% C

ontr

ol

2010: Plymouth Country Club

13 13 9 lsd p=.05

Goosegrass

Nontreated

Photo: Aug 19, 2010

Plymouth Country Club

Specticle 20WSP

2.5 oz/acre

Applied Mar 8, 2010

Photo: Aug 19, 2010

PRE Weed Management Strategies

Tower (6L): dimethenamid

Labeled in 2010 for golf course use only

Supplemental label expires Oct 1, 2014 for sod

farm, commercial and recreational turf

Poor crabgrass but excellent goosegrass control

21 to 32 fl oz/acre rate (do not exceed 64 fl oz/year)

Bermuda, centipede, zoysia, St. Augustine tolerant

Check

Tower 1 qt/A

Mar 8 and Apr 20

Photo Aug 2, 2010