Late Summer Weed Management
Programs in Warm Season Turf
Jul 11, 2013
L. S. Warren (08-20-13)
North Carolina State University
JULY – SEPTEMBER
Weed Management Options
Summer Annual and Perennial Grasses
Nutsedge Species
Kyllinga Species
Summer Annual and Perennial Broadleaves
(July - September)
Initiate applications (What are you waiting for!!??)
OR
Repeat applications (hopefully started last quarter)
Problems with July - September Applications
• Weeds more mature (tillers, tubers, seedheads)
Higher rates usually needed for larger plants
Herbicides poor on tubers – useless on seedheads
• Many herbicides not recommended > 90 F and dry
Volatility concerns
Weeds not actively growing when drought stressed
• Many herbicides interfere with overseeding timings
Jun 24, 2013
Dogfennel
Turf Weed Management Topics
[Jul-Sep] Weed Control Options
Summer Weed: Dallisgrass – POST
Winter Weed:
Annual bluegrass – PRE
Dallisgrass Control
In Bermudagrass
(very difficult)
Repeat applications of
MSMA in bermudagrass
did control but can’t
legally spray due to EPA
restrictions except on
golf courses or sod farms
Dallisgrass
Aug 21, 2010
Dallisgrass Control in Common
Bermudagrass
Excellent temporary control can be achieved
with 4 week sequential applications of…
Celsius 68WG
Revolver 0.19SC
Nonionic surfactant
4.9 oz/A
2 fl oz/M
0.25%
Late summer timings seem to work best.
Thiencarbazone + Iodosulfuron + Dicamba (68WG)
Use on bermuda, zoysia, centipede and St. Augustinegrass
Controls crabgrass, foxtail, bahiagrass, bull paspalum and
many broadleaf weeds (summer and winter)
Overseed ryegrass 2 week after application
Apply 30 days prior to seeding bermuda or zoysia or wait
2 to 3 weeks after seedling or sprig emergence to apply
Celsius WG
• Golf, sod production, residential, commercial
properties, sports facilities, roadsides
• Pre-emergent (residual) control up to 60 days on
some weeds
• Mix with Quicksilver or Octane to increase speed
of control in periods of cool weather.
• Best results when average daily temp. > 60°F
• Reduced risk of significant phytotoxicity with
applications made at high temperatures
Celsius WG Applications
• Rates: 2.5, 3.7, or 4.9 oz/a
– Maximum use rate of 7.4 oz/a annually
• 2.5 oz/a applied 3 times, 2-4 wks apart as needed
• 3.7 oz/a applied 2 times, 2-4 wks apart as needed
• 4.9 fb 2.5 oz/a, 2-4 wks apart as needed
Non-ionic surfactant or methylated seed oil
improves control
Dismiss South 4SC Combinations for Post
Dallisgrass Control in Common Bermudagrass
% Control
14
4
9
11
lsd p=.05
100
Dismiss South
0.626 pt/A
80
Dismiss South
0.76 pt/A
60
Dismiss South
0.9 pt/A
40
Dismiss South
0.626 pt/A fb 0.28 pt/A
20
Dismiss South
0.438 pt/A fb 0.46 pt/A
0
6-Sep
13-Sep
27-Sep
2011: The River Golf Club
12-Oct
Celsius + Revolver +
Induce
4.9 oz/A +
2 fl oz/M + 0.,25%
Check
Applied Aug 30 and Sep 13
Late Season Dallisgrass Control in
Common Bermudagrass
2
LSD ( P = .05)
% Green Cover
100
60
Celsius + Revolver +
Induce
4.9 oz/A + 2 fl oz/M +
0.5%
40
Check
80
20
0
PASDI Nov 15, 2011
Applied Oct 4 and Nov 2, 2011: River Club
Tribute Total 60.5 WDG
 Bayer Environmental Sciences
 Thiencarbazone + foramsulfuron + halosulfuron
 Control: early POST crabgrass, goosegrass, annual
broadleaves, annual sedges, dallisgrass, perennial ryegrass
 Residential and commercial bermudagrass and zoysiagrass
 For dallisgrass, later summer applications are best. Have
good soil moisture at the time of application. Two
applications ~ 30 days apart; then retreat following spring
1 to 2 weeks after first sign of regrowth
 Rate: 1 to 3.2 oz/acre, do not exceed 6.4 oz/acre yearly
 Add MSO at 0.25-0.5% v/v and AMS at 1.5-3 lb/A
Late Season Dallisgrass Control in Common
Bermuda Using Tribute Total and Imazamox
11
1
16
32
100
LSD p=.05
Imazamox 1AS + NIS
0.5 pt/A + 0.25%
% Control
80
Imazamox 1AS + NIS
0.75 pt/A + 0.25%
60
40
Tribute Total 60.51WG
+ MSO + AMS 3.2
oz/A + 0.5% + 3 lb/A
20
Check
0
12-Nov
26-Nov
22-Apr
20-May
Lake Wheeler Turf Field Lab: 2012-13
Applied Oct 16 and Nov 5
Dallisgrass Control in Common Bermuda
Using 3.2 oz/A Tribute Total
1
LSD p=.05
100
Applied Sep 10, Oct 16
and May 14 with 0.5%
MSO and 3 lb/A AMS
% Control
80
60
40
Check
20
0
PASDI Jul 8
Lake Wheeler Turf Field Lab: 2012-13
We’ve had mild summer temperature and lots of rain
Therefore…
Expect early poa germination this year
(late Aug – early Sep)
Apr 23, 2013
PRE Poa annua Control in Warm-Season
Turf Overseeded With Perennial Ryegrass
Balan
120 lb/acre
Apply 6 weeks before overseeding
Dimension Ultra WSP
1.25 lb/acre
Dimension 2EW
2 pt/acre
Apply 6 to 8 weeks before overseeding
Barricade 65WG
0.58 to 1 lb/acre
Barricade 4FL
12-21 fl oz/acre
Apply 8 to 10 weeks before overseeding
Target early to mid October for overseeding
PRE Poa annua Control in Established
Warm and Cool-Season Turf
Team Pro
Pendulum Aquacap
Betasan, Bensumec, PreSan
Barricade
Ronstar
2 lb ai/acre
1.5 to 2 lb ai/acre
12.5 lb ai/acre
0.5 to 1 lb ai/acre
2 lb ai/acre
Along with Balan and Dimension, these products are all
labeled in established tall fescue, Kentucky bluegrass,
perennial ryegrass, bermudagrass, St. Augustinegrass
and zoysiagrass.
Ronstar Formulations
Oxadiazon
(Ronstar G, 50WSP, 3.17SC)
Absorbed by shoots only, inhibits photosynthesis
Does not inhibit root growth
Therefore, use this product in worn turf or where
additional grow-in is desired (athletic fields)
Not labeled for home use!!!
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̵
̵
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Specticle
Broadleaf spectrum similar to DNA & triazine
herbicides – doesn’t stain like DNAs
Cellulose biosynthesis inhibitor (alkylazine
herbicide family)
Long soil residual (overseeding concerns)
Sold as 20WSP or 0.622 flowable formulation
Specticle 20WSP
Tolerant turf species
Centipedegrass
St. Augustinegrass
Bermudagrass
Zoysiagrass
Seashore paspalum
Buffalograss
Bahiagrass
Max. single rate (oz/A)
2.5
2.5
5
5
5
5
5
Specticle 20WSP
General Use:
• Do not exceed 5 oz/A per application or 7.1 oz/A
per calendar year
• Do not apply to newly seeded (< 1 year after
establishment)
Specticle Flo
Tolerant turf species
Centipedegrass
St. Augustinegrass
Bermudagrass
Zoysiagrass
Buffalograss
Bahiagrass
Max. single rate (fl oz/A)
6
6
10
10
10
10
Specticle Flo
General Use:
• Do not exceed the maximum specified single
application rate for each turf species or 18.5 fl
oz/A per calendar year
• Do not apply to newly seeded or sprigged turf (<
16 month after establishment)
Specticle
Acceptable Turf Sites
•
•
•
•
•
•
Golf course turf – not putting greens
Sod farms
Sports fields
Home and commercial lawns
Parks
Cemeteries
Specticle 20WSP
•
•
•
•
•
Specific use rates (oz/A)
Crabgrass spp.
2.5 to 4.375 - good
Goosegrass
3.75 to 5 - great
Annual bluegrass
2.5 to 3.75 - great
Annual sedge
3.75 to 5
Broadleaf weeds
2.5 to 5
• Also controls barnyardgrass, foxtail spp., ryegrass
spp., green kyllinga
• Also has early POST activity
Specticle Flo
•
•
•
•
•
Specific use rates (fl oz/A)
Crabgrass spp.
6 to 10 - good
Goosegrass
6 to 10 - great
Annual bluegrass
6 to 10 - great
Broadleaf weeds
6 to 10
Annual sedge and kyllinga
10
• Also controls barnyardgrass, foxtail spp., ryegrass
spp., green kyllinga
• Also has early POST activity
Specticle 20WSP
Rate (oz/A)
2.5
3.75
4.375
5.0
Overseeding Intervals
8 months
12 months
12 months
12 months
Specticle Flo
Rate (fl oz/A)
4.5 – 6
6-9
Overseeding Intervals
10 months
12 months
PRE Poa annua Control in Established
Warm Season Turf Only
Specticle
Will also control poa annua early post very well but
may have to increase rate based on plant size
(August through early October timing)
Nontreated
Photo Apr 12, 2010
Specticle 3.75 oz/A
Applied Sep 15, 2009
Photo Apr 12, 2010
POAAN Control in Common Bermuda Using
Specticle 20WP and Barricade 65WG
28
29
22
15
100
% Control
80
60
40
20
0
4-Jan
7-Feb
1-Mar
4-Apr
2010-11: Thorndale Country Club
lsd p=.05
Specticle 2.5 oz/A
Sep 2 (Pre)
Specticle 2.5 oz/A
Oct 5 (1 leaf)
Specticle 2.5 oz/A
Nov 8 (1 tiller)
Specticle 3.75 oz/A
Sep 2 (Pre)
Specticle 3.75 oz/A
Oct 5 (1 leaf)
Specticle 3.75 oz/A
Nov 8 (1 tiller)
Barricade 1.15 lb/A
Sep 2 and Nov 8
Barricade 1.15 lb/A
Sep 2 (Pre)
Check
Pre POAAN, LOLPE, APHAR and DIGIS Control
Using Specticle 20WP and Barricade 4FL
13
8
10
21
21
100
lsd p=.05
Specticle 2.5 oz/A
80
% Control
Specticle 3.75 oz/A
60
Specticle 5.35 oz/A
40
Barricade 1 pt/A
20
Barricade 1.5 pt/A
0
POAAN
May 3
APHAR
May 3
2009-10: Wake County
DIGIS
Sep 8
Check
Applied Sep 15, 2009
Preemergence POAAN and DIGIS Control
Using Specticle 20WP and Barricade 4FL
6
26
17
23
32
100
lsd p=.05
Specticle 2.5 oz/A
80
% Control
Specticle 3.75 oz/A
60
Specticle 5.35 oz/A
40
Barricade 1 pt/A
20
Barricade 1.5 pt/A
0
POAAN
May 3
DIGIS
Jul 6
DIGIS
SEP 7
2009-10: Thorndale Country Club
Check
Applied Sep 15, 2009
Long Term POAAN and DIGIS Control in
Common Bermuda Using Specticle
19
29
100
% Control
80
60
40
20
0
POAAN 04-02-12
DIGIS 09-03-12
Thorndale Country Club (2010-12)
lsd p=.05
Specticle 3.75 oz/A
Sep 2010
Specticle 3.75 oz/A
Mar 2011
Specticle 3.75 oz/A
Sep 2010 & 11
Specticle 3.75 oz/A
Mar 2011 & 12
Specticle 3.75 oz/A
Sep / Mar (2010-12)
Ronstar Flo 7.6 pt/A
Mar 2011
Ronstar Flo 7.6 pt/A
Mar 2011 & 12
Barricade 65WG 1.15
lb/A Mar 2011 & 12
Check