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Efficacy and Cost of Selected Herbicides for Control of Skunkvine (Paederia foetida)
Chris Marble
University of Florida/IFAS
Mid-Florida Research and Education Center
Apopka, FL
Introduction to Paederia foetida• Fast growing woody vine
• Native to southern Asia
• Introduced as a fiber (and ornamental) crop in 1800’s
• Category I invasive in FL, found in at least 25 counties, legally noxious in 1999
• Also found in Hawaii, Texas, Lousiana, Georgia, Carolinas, Alabama, Mississippi, Tennessee
Paederia in St. Augustine turf; Orlando, Florida
Introduction to Paederia foetida
Rubiaceae family No thorns Rounded to cordate leaves, opposite, entire margins
Flowers on long petioles, white with red centers Small, spherical fruit, shiny brown, 2 black seeds
Introduction to Paederia foetida• Can reproduce from seed,
stem fragments, small stolons, rooting along nodes
• Mechanical, manual removal efforts have been unsuccessful
• Currently recommended treatments:• Triclopyr amine/ester,
imazapic, glyphosate, aminopyralid
• Re-sprouting can still be observed (Langeland et al., 2006)
Objectives:
• Determine most effective and economical treatment for skunkvine and establish maintenance intervals (for subsequent applications)
Methods:• Cuttings taken from wild
populations in Hillsborough, Orange, and Alachua County on 3 separate dates: • September 15, October 16,
November 27, 2016
• Current season’s growth
• Stuck in Fafard 52 potting mix (SunGro Horticulture) and fertilized
• Misted 5 seconds every 10 minutes from 7:30 am to 4:30 pm
Methods:• Transplanted into #1 (1 gal.)
nursery containers and staked on 3 separate dates – continued to grow until treatment
1. Small (green, softwood, immature foliage, 12 to 24 in.)
2. Middle (mostly hardwood, mature foliage, 24 to 48 in.)
3. Large (mostly hardwood, 48 to 72 in. in ht.)
4. **XL (all hardwood, trimmed to 72 in., potted for over 1 yr(stepped up) – 2nd year only)
• Grouped by growth stage, blocked based upon size
“Mature stage”
Small Middle
Large XL
Treatments:Active Ingredient:
Trade Name:
WSSA Group:
Rates:
Triclopyr amine Garlon 3A 4 0.75, 1.5, 3.0, & 6.0 lbs. aea
Triclopyr ester Garlon 4 4 0.75, 1.5, 3.0, & 6.0 lbs. aea
Glyphosate Ranger Pro 9 0.75, 1.5, 3.0, & 6.0 lbs. aea
Imazapic Plateau 2 0.02, 0.05, 0.09, & 0.19 lbs. aia
Aminopyralid Milestone 4 0.014, 0.028, 0.055, & 0.11 lbs aia
Fluroxypyr Vista 4 0.06, 0.12, 0.24, & 0.48 lbs aea
AminocyclopyrachlorMethod 240SL
4 0.035, 0.07, 0.14, & 0.28 lbs aea
*Rates generally 0.125, 0.25, 0.5, and 1.0× maximum or recommended label rate.**Group 2 = Acetolactate synthase (ALS) inhibitor; Group 4 = synthetic auxins; Group 9 = EPSP synthesis inhibititor, amino acid synthesis inhibitor
Methods:• Herbicide treatments applied outside of
greenhouse using CO2 backpack sprayer, 25 gpa; Surfactants added based on manufacturer label
• Data collected:• Visual control ratings (0 to 100% control) at monthly
intervals for 2 months
• After 2 months, half replications were harvested for shoot and root FW (N=10)
• Converted to Percent Control = 100 x (1-(mean wt. treated/mean wt. control)).
• After 2 additional months, regrowth from 10 initial replications plus 10 remaining replications were harvested**
RESULTS
Results: Greenhouse TrialsSmallest Stage; Year 1 – 2 MAT*Rate increases from left to right*
Triclopyr amineGarlon 3A
Triclopyr esterGarlon 4
GlyphosateRanger PRO
ImazapicPlateau
AminopyralidMilestone
FluroxypyrVISTA
AminocyclopyralclorMethod
Results: Greenhouse TrialsLarge Stage; Year 1 – 2 MAT*Rate increases from left to right*
Triclopyr amineGarlon 3A
Triclopyr esterGarlon 4
GlyphosateRanger PRO
ImazapicPlateau
AminopyralidMilestone
FluroxypyrVISTA
AminocyclopyralclorMethod
Results: Greenhouse TrialsXL Stage; Year 2 – 2 MAT*Rate increases from left to right*
Triclopyr amine Triclopyr ester Glyphosate
Imazapic Aminopyralid Fluroxypyr
Aminocyclopyralclor
Triclopyr amineGarlon 3A
Triclopyr esterGarlon 4
GlyphosateRanger PRO
ImazapicPlateau
AminopyralidMilestone
FluroxypyrVISTA
AminocyclopyralclorMethod
Table 2. Influence of herbicide on skunkvine efficacy across multiple growth
stagesz in 2016 and 2017 greenhouse experiments.
Percent Controly
2016 2017
Herbicidex 2MATw 4MAT 2MAT 4MAT
Aminocyclopyrachlor 95 abv 96 a 85 a 97 a
Aminopyralid 90 c 85 c 82 a 93 a
Fluroxypyr 91 bc 87 bc 64 c 85 b
Glyphosate 95 ab 96 a 71 bc 90 ab
Imazapic 66 d 55 d 34 d 61 c
Triclopyr amine 96 a 91 ab 79 ab 92 a
Triclopyr ester 97 a 97 a 85 a 95 a
Estimated cost for 90% control from each herbicide across all three growth
stages at both 2 and 4 MAT.
Herbicide Rate needed: Cost per acre:
Triclopyr amine 3 lbs. aea $83.50
Triclopyr ester 1.5 lbs. aea $34.66
Glyphosate 3 lbs. aea $36.00
Imazapic **** ****
Aminopyralid 0.11 lbs. aia $17.32
Fluroxypyr 0.48 lbs. aea $32.40
Aminocyclopyrachlor 0.28 lbs. aea $43.54
Results:
*Average price paid in Central Florida, does not include generics, quantity discounts, etc.
Results:• Few differences noted among herbicides at labeled
rates; exception was imazapic
• At 2 MAT, most economical herbicides were:• Fluroxypyr at 0.5× = $16.20
• Aminopyralid at 1× = $17.32
• Triclopyr ester at 0.5× = $17.33
• At 4 MAT, most economical herbicides were:• Aminopyralid at 1× = $17.32
• Fluroxypyr at 1× = $32.40
• Glyphosate at 0.5× = $36.00
Conclusion:• Fluroxypyr, aminopyralid, triclopyr ester
provided effective control at label rates
• Glyphosate, triclopyr amine, and aminocyclopyrachlor also effective – may have been more economical depending on growth stage
• Minimal to no re-sprouting was observed on most treatments• Vines chosen for trials were shorter than may be
encountered in field
Preemergence Control
Barricade SureGuard Specticle Tower Gallery Check
Trade name Barricade SureGuard Specticle Tower Gallery
Active prodiamine flumioxazin indaziflam dimethenamid-p isoxaben
WSSA group 3 14 29 15 21
84 b
99 a
48 c
60 c
2 d
0
10
20
30
40
50
60
70
80
90
100
Barricade SureGuard Specticle SC Tower Gallery
Dry
wt.
Red
uct
ion
%
Premergence control of skunkvine: 12 WAT
Methods:• Field trials: Year 2
• 2 Locations in Central FL. (Orange County)
• Herbicides applied at 1x label rate
Table 3. Efficacy of selected herbicides for control of skunkvine in field evaluations.
Treatment % Control ratingsa Shoot Fresh Wt. (g)
Herbicide Rate (kg ha-1)b 2MATc 4MAT 8MAT 12 MAT
Method 0.08 91 abd 100 a 95 ab 91 ab
Milestone 0.07 83 b 100 a 93 ab 99 a
Vista 0.27 79 bc 95 a 70 ab 86 b
Ranger Pro 1.68 95 ab 100 a 95 ab 98 a
Plateau 0.21 63 c 78 b 68 b 95 ab
Garlon 3A 1.68 90 ab 96 a 100 a 100 a
Garlon 4 1.68 100 a 100 a 100 a 99 a
aControl ratings taken on a scale of 0 to 100, 0 = no control, 100 = dead plant (no green tissue
visible).
bRates for imazapic and aminopyralid are shown as kg active ingredient while all others are
presented in acid equivalents.
cMAT = months after treatment.
dMeans within a column followed by the same letter are not significantly different (Fisher's LSD, p
< 0.05).
Field evaluations:
9199
86
98
85
100 99
0
10
20
30
40
50
60
70
80
90
100
Method Milestone Vista Glyphosate Plateau Garlon 3A Garlon 4
Percent Control at 12 mo. after treating
Conclusions:• Several herbicides evaluated provided consistent
control depending on rate and growth stage• Garlon (3A and 4), glyphosate, Milestone, Method
• Preemergence herbicides (SureGuard) could be used in smaller confined spaces to prevent re-infestation through seed
• Proper choice depends on growth stage, non-target species, economics (e.g. Milestone)
• Full coverage difficult to achieve – non-target injury a major concern
• More work needed on application methods
