Transcript Slide Presentation (PowerPoint, 3.7 MB)

Weed Control in Sod Production Fields
Tim R. Murphy
The University of Georgia
Weed Problems in Sod
Intensive irrigation and fertility effects
Effect of herbicides on sod
Row crop weeds
Common bermudagrass control
Row crop vs. turf herbicides
– Same ai and formulation
Cultural Control
Avoid over-irrigation
Install drainage if needed
Properly mow on schedule
– Will control most tall-growing broadleaf weeds
Maintain pH and fertility
Control insects and diseases
Know weed spectrum
Hit or Miss
Vs.
Planned Program
PrePlant Weed Control
Essential for common bermudagrass control
– Will require one fallow season
Roundup Pro
– Still the best herbicide unless fumigation is used
– Repeat applications will be needed
Roundup Rate and Bermudagrass Control
% Control
53 DAT
80
70
60
50
40
30
20
10
0
116 DAT
80
75
58
0
2 qts
0
5 qts
0
10 qts
Roundup Rate/Acre
DAT = Days after Treatment
% Control - 1 YR
Bermuda Control with Roundup – 1 yr.
100
90
80
70
60
50
40
30
20
10
0
99
65
56
4qt/2X
2qt/3X
Rate Qt/Acre / No. of Apps.
2qt/2X
Bermudagrass Control with Roundup
(averaged across Tifway, Tifgreen, Tifdwarf, Ormond)
Rate (qt.acre) Applications
2
2.0
3
2.0
2
3.0
3
3.0
1
4.0
2
4.0
3
4.0
% Bermuda
Regrowth
47
1
26
1
60
28
2
Applied in late May, late June and Mid-August. Mowed at 1.0 inch.
Rated June of year after application
“Newer” Sod Herbicides
Envoy - centipedegrass
Lontrel
Confront
Drive
Manor, Blade
Corsair
“Newer” Sod Herbicides
Prompt 5L
Label changes for Kerb
Envoy (Valent)
SLN Georgia Label
Centipede sod farms only
Suppresses bermudagrass
Controls annual grasses
Not for use on seed fields
Apply 3 wks after green-up
Delay mowing 7 days before and after
Envoy - Bermuda Suppression
Two applications at 34.0 fl. oz./acre
Four applications at 17.0 fl. oz./acre
1st - 3 to 6 inch bermuda growth
2nd, 3rd, 4th - 3 to 3 inch bermuda growth
Also controls most other annual grasses
Envoy
Clethodim
0.94 lbs./gal. - EC
17.0 to 34.0 fl. oz./acre
Add nonionic surfactant at 0.25% v/v
Sethoxydim (Vantage) - Centipedegrass
Controls annual grasses
Suppresses bahiagrass and bermudagrass
No annual bluegrass control
No nutsedge (nutgrass) control
Vantage - Centipedegrass
No COC needed
Established
Seedling - 3 in. stolon growth
Delay mowing 7 d before and after application
Vantage – Bahiagrass Suppression
2.25 pts./acre
Delay mowing – 7 d before and after application
Repeat application - 10 to 14 days
Bahia must be actively-growing
Lontrel - DowAgrosciences
3.0 lb./gal. clopyralid
Highly active on legumes and aster weeds
Also controls curly dock, smartweed
Rate 1/4 to 1.0 pt./acre
High rate needed for smartweed
Will not control dichondra (ponyfoot)
Turfgrass Tolerance to Lontrel
Turfgrass
Tolerance to Lontrel
Kentucky Bluegrass
T
Tall Fescue
T
Bermudagrass
T
Centipedegrass
T
St. Augustinegrass
T
Zoysiagrass
T
Confront - DowAgrosciences
Triclopyr + clopyralid (2.25 + 0.75 lbs./gal.)
Amine formulation
Active on wide range of broadleaf weeds
Clopyralid highly active on asters and legumes
Triclopyr controls chickweeds, henbit, mat
lippia, lambsquarters, Va. Pepperweed,
shepherdspurse
Turfgrass Tolerance to Confront
Turfgrass
Tolerance to Confront
Kentucky Bluegrass
T
Tall Fescue
T
Bermudagrass
Centipedegrass
I
(avoid summer, greenup)
T
St. Augustinegrass
S
Zoysiagrass
T
Confront
Use 1.0 to 2.0 pts./acre
Use on healthy, well established turf
Delay reseeding for 3 weeks
Mow seedling turf 2 to 3 times before
application
Needs 6 hour rain-free period
Drive - TopPro
Quinclorac 75 DF
Add crop oil concentrate (2.0 pts./acre)
Labeled on tall fescue, Ky. Bluegrass,
zoysiagrass, bermudagrass
DO NOT use on centipedegrass or St.
Augustinegrass
Drive - TopPro
May be used before or after sprigging
zoysiagrass
Controls crabgrass (except smooth), white
clover, hop clovers, speedwell, dollarweed
Torpedograss - requires 2 to 3 applications
Will not control goosegrass
Use with extreme caution near tomatoes, bell
peppers, etc.
Manor, Blade
Metsulfuron 60 DF
Excellent option for ‘Pensacola’ bahiagrass and
broadleaf control in warm-season turfgrasses
Do not use on bahiagrass
Low rate - < 1.0 oz. product/acre
Use only 0.25 to 0.5 oz/acre on centipede
Use with nonionic surfactant
Corsair - Riverdale
Chlorsulfuron 75%
Used primarily for spot control of clumpy tall
fescue in bermuda, zoysia, centipede, St.
Augustine, Ky. Bluegrass – works slowly
Avoid transition applications on centipede,
zoysia, St. Augustine
Repeat application in 60 d
Add NIS at ¼ to 1/3 fl. oz./gallon of spray mix
Prompt - TopPro
Pre-mix of bentazon+atrazine (2.5 lbs./gal. each)
Labeled for bermuda, centipede, St. Augustine,
zoysia (some injury to bermuda)
Good option for yellow nutsedge, kyllinga, globe
sedge, and numerous broadleaf weeds
May be used 10 d after sprigging
2.4 pts./acre, repeat 7 to 10 d later for sedges
Kerb – Rohm & Haas
Label expanded to include centipede, St.
Augustine and zoysia
Perennial ryegrass removal – apply at 50%
green-up growth stage
Poa annua control during winter months
Needs rainfall or irrigation event (0.25 in.)
within 24 to 48 hrs
At-Sprigging Options
Ronstar 2G - bermuda, zoysia, paspalum
Ronstar 50WSP - bermuda
Atrazine - centipede, St. Augustine, zoysia
Simazine - centipede, St. Augustine, zoysia
Ronstar 2G and 50WSP - At Sprigging
2G - 100 to 150 lbs./acre
50WSP - 4.0 to 6.0 lbs./acre
Apply immediately before or after sprigging
Pre-sprigging (1 day before sprigging slightly
safer than post-sprigging)
Irrigate ASAP for best results
Atrazine and Simazine - At Sprigging
Centipede, St. Augustine, zoysia
Atrazine - labeled up to April 15
Simazine - labeled up to June 1
Do not apply within 30 days before lifting
Apply 2 days after lifting sod on old beds - FL
Apply 7 to 10 days after sprigging - FL
TOLERANCE OF NEWLY-SPRIGGED CENTIPEDEGRASS TO
ATRAZINE AND SIMAZINE
CENTIPEDEGRASS
GROUND COVER (%)
WKS AFTER
HERBICIDE QTS./ACRE SPRIGGING
ATRAZINE
1.0
0
2.0
0
1.0
0,3
SIMAZINE
1.0
0
2.0
0
1.0
0,3
NONE
1
JOHNSON, 1976
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15 WAT
24
30
20
30
26
25
21 WAT
39
47
37
45
50
43
12
15
The majority of herbicides used in turfgrasses for preemergence
annual grass control are dinitroanilines and dithiopyr
DNA’s
 Barricade
 Pendulum
 Surflan
 Balan
 Treflan
 Dimension
 Best used on
established turf.
 Mitotic inhibitors.
 Relatively immobile
in the soil
 Minimal use in sod
fields
DNA and Dimension root inhibition
pendimethalin on
zoysiagrass
Surflan on St.
Augustinegrass
Swollen, club shaped roots
Dimension on
bermudagrass
Sedge Herbicides - Turfgrasses
Basagran T/O - yellow, annual sedges
Manage - yellow, purple, annual sedges
MSMA/DSMA - yellow, purple, annual sedges
Image - yellow, purple, annual sedges
Pennant - yellow, annual sedges
2,4-D - yellow, very poor activity
UGA Turf Weed Science Web Page
www.georgiaturf.com
193 weed species
30 popular articles
UGA turf weed science recommendations
links to herbicide labels, MSDS
UGA Weed Science Web Site
www.gaweed.com
Covers all crops including turf and ornamentals
Weed Identification
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