Efficacy and Cost of Selected Herbicides for Control of Skunkvine (Paederia foetida)

Transcription

1 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

2 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

3 Paederia in St. Augustine turf; Orlando, Florida

4 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

5 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)

6 Objectives: Determine most effective and economical treatment for skunkvine and establish maintenance intervals (for subsequent applications)

7 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

8 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) 2 nd year only) Grouped by growth stage, blocked based upon size Mature stage

9 Small Middle Large XL

10 Treatments: Active Ingredient: Trade Name: WSSA Group: Rates: Triclopyr amine Garlon 3A , 1.5, 3.0, & 6.0 lbs. aea Triclopyr ester Garlon , 1.5, 3.0, & 6.0 lbs. aea Glyphosate Ranger Pro , 1.5, 3.0, & 6.0 lbs. aea Imazapic Plateau , 0.05, 0.09, & 0.19 lbs. aia Aminopyralid Milestone , 0.028, 0.055, & 0.11 lbs aia Fluroxypyr Vista , 0.12, 0.24, & 0.48 lbs aea Aminocyclopyrachlor Method 240SL , 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

11 Methods: Herbicide treatments applied outside of greenhouse using CO 2 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**

12 RESULTS

13 Triclopyr amine Garlon 3A Triclopyr ester Garlon 4 Glyphosate Ranger PRO Imazapic Plateau Aminopyralid Milestone Fluroxypyr VISTA Results: Greenhouse Trials Smallest Stage; Year 1 2 MAT *Rate increases from left to right* Aminocyclopyralclor Method

14 Triclopyr amine Garlon 3A Triclopyr ester Garlon 4 Glyphosate Ranger PRO Imazapic Plateau Aminopyralid Milestone Fluroxypyr VISTA Results: Greenhouse Trials Large Stage; Year 1 2 MAT *Rate increases from left to right* Aminocyclopyralclor Method

15 Triclopyr amine Triclopyr ester Glyphosate Garlon 3A Garlon 4 Ranger PRO Imazapic Aminopyralid Fluroxypyr Plateau Milestone VISTA Results: Greenhouse Trials XL Stage; Year 2 2 MAT *Rate increases from left to right* Aminocyclopyralclor Aminocyclopyralclor Method

16 Table 2. Influence of herbicide on skunkvine efficacy across multiple growth stages z in 2016 and 2017 greenhouse experiments. Percent Control y Herbicide x 2MAT w 4MAT 2MAT 4MAT Aminocyclopyrachlor 95 ab v 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

17 Results: 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 *Average price paid in Central Florida, does not include generics, quantity discounts, etc.

18 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

19 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

20 Preemergence Control Barricade SureGuard Specticle Tower Gallery Check Trade name Barricade SureGuard Specticle Tower Gallery Active prodiamine flumioxazin indaziflam dimethenamid-p isoxaben WSSA group

21 Dry wt. Reduction % Premergence control of skunkvine: 12 WAT a b c 60 c Barricade SureGuard Specticle SC Tower Gallery 2 d

22 Methods: Field trials: Year 2 2 Locations in Central FL. (Orange County) Herbicides applied at 1x label rate

23 Table 3. Efficacy of selected herbicides for control of skunkvine in field evaluations. Treatment % Control ratings a Shoot Fresh Wt. (g) Herbicide Rate (kg ha -1 ) b 2MAT c 4MAT 8MAT 12 MAT Method ab d 100 a 95 ab 91 ab Milestone b 100 a 93 ab 99 a Vista bc 95 a 70 ab 86 b Ranger Pro ab 100 a 95 ab 98 a Plateau c 78 b 68 b 95 ab Garlon 3A ab 96 a 100 a 100 a Garlon a 100 a 100 a 99 a a Control ratings taken on a scale of 0 to 100, 0 = no control, 100 = dead plant (no green tissue visible). b Rates for imazapic and aminopyralid are shown as kg active ingredient while all others are presented in acid equivalents. c MAT = months after treatment. d Means within a column followed by the same letter are not significantly different (Fisher's LSD, p < 0.05).

24 Field evaluations: Percent Control at 12 mo. after treating Method Milestone Vista Glyphosate Plateau Garlon 3A Garlon 4

25 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 reinfestation 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

26 Acknowledgements: Chris Marble, Cell: