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)
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
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
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
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.
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
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!!!!!
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
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
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