Herbicide Control ofLygodium microphyllum

Jeff Hutchinson and Dr. Ken LangelandUniversity of Florida, Department of Agronomy

Center for Aquatic and Invasive Plants

EISS 2007

Recommended Herbicides

Site Dependent• Wet (water present)

1) Glyphosate

2) Triclopyr

• Dry (no water present)

1) Metsulfuron methyl

2) Imazapic

NOTES:1) Refer to label prior to herbicide application

2) Use 0.5% non-ionic surfactant (v/v) with all herbicides and mixtures

RATES

Ground Aerial

High Volume Low Volume

Glyphosate 1-3% product 3.75-7.5 pt / 20 gal

Triclopyr 1-2% product N/A

Imazapic 0.75-1.5 % product N/A

Metsulfuron 2 oz / 100 gal 2 oz / 20 gal

Tank Mixes

• Combinations of:

1) Glyphosate

2) Metsulfuron methyl

3) Triclopyr 4) Imazapic

Tank Mixes

• For heavy infestations, tank mixes should not exceed 4% total products.

• For light to medium infestations, tank mixes should not exceed 2% total products.

• Need to take into account ca. density of native plants at treatment site.

Rotation and Tank Mixes of Herbicides

Resistance prevention

MetsulfuronImazapicImazapyrImazamox

MetsulfuronImazapicImazapyrImazamox

GlyphosateGlyphosate

TriclopyrTriclopyr

Non-Target Damage• Expect non-target damage

- Depends on Lygodium density

• Native ferns

• Rare plants

InitialTreatment

Follow-up Treatments

Cut or not cut?• Poodle-cut / Spray • No poodle-cut / Spray

Monitoring / Re-treatment

1. Re-growth occurs quickly following treatment

2. Treated sites need to be re-visited every 6 months (minimum)

3. Treat all re-growth

Average Treatment Cost / Ha

$400 $600 $800 $1000 $1200 $1400

Cut andSpray

(Rodeo)

Aerial(Rodeo)

Aerial(Escort)

Ground Treatments(ca. $1600+)

or $630/acre

Aerial Treatments(ca. $185)or $73/acre

$1600$200$100

Research

0

5

10

15

20

25

30

35

Cut/S

pra

y

Basa

l

Folia

r 25%

Folia

r 50%

Folia

r 100%

Cut/S

pra

y

Basa

l

Folia

r 25%

Folia

r 50%

Folia

r 100%

Cut/S

pra

y

Basa

l

Folia

r 25%

Folia

r 50%

Folia

r 100%

Glyphosate Mesulfuron Triclopyr

Herbicide and Treatment

% T

ran

slo

cate

d

Rhiozomes

Bottom 50%

Top 50%

14C Herbicide Translocation Results

**

** ****

**

**

Metsulfuron

methyl

Triclopyr

Greenhouse Herbicide ScreeningDry Weight Biomass (post-treatment)

Herbicide Dry Weight (g)

Glyphosate 0.13

Metsulfuron methyl 0.61

Imazapyr 4.07

Imazapic 3.58

Quinclorac 8.01

Penoxsulam 7.71

Imazamox 10.37

Triclopyr 0.00

Control 9.68

Herbicide Rate (kg a.e.) Dry Weight (g)

Imazamox 0.06 2.27

0.12 0.35

0.24 0.03

0.48 0.01

Fluroxypyr 5.25 6.34

10.5 8.63

21.0 3.51

42.0 1.00

Aminopyralid 0.015 2.09

0.03 5.35

0.06 0.48

0.12 3.84

Dry Weight Biomass

Herbicide

% ChangeL. microphyllum

% ChangeNative Plants

% ChangeSpecies Richness

Glyphosate 2% - 84.1 - 56.9 + 2.8

Metsulfuron 2 oz - 74.6 - 31.6 + 2.5

Triclopyr 2% - 91.5 - 31.4 - 5.1

Imazapic 1.5% - 82.8 - 71.5 - 48.5

Metsulfuron +

Glyphosate

- 89.1 - 53.8 - 27.3

Metsulfuron +

Triclopyr

- 91.5 - 43.6 - 24.3

Glyphosate +

Imazapic

- 92.4 - 55.3 - 30.1

Field Trial Results (6 months)

Aerial Application - Loxahatchee NWRLygodium microphyllum

Pre-treatment 1 Year Post Trt

Treatment Mean S.E. Mean S.E. % Change

Escort 2 oz 67.33 4.40 0.38 0.14 - 99.44

Escort 4 oz 59.46 2.62 1.47 0.48 - 97.53

Rodeo 3.75 pt. 66.50 3.64 7.00 1.62 - 89.47

Rodeo 7.50 pt. 69.72 2.35 8.07 1.31 - 88.43

Control 46.01 5.14 56.97 4.79 + 23.82

Swamp fern

Cinnamon fern

Virginia chain fern Royal fern

Wild grape

Green brier

Escort

(2 oz)

Pre 22.4 1.1 0.4 0.8 8.6 10.4

1 Yr 1.5 0.1 <0.1 0.0 21.2 0.9

% Change -93.5 -90.2 -94.8 -100.0 +147.4 -91.7

Escort

(4 oz)

Pre 26.3 0.7 0.5 1.3 9.3 14.4

1 Yr 3.1 0.4 0.3 0.3 23.0 0.5

% Change -88.4 -45.1 -44.3 -77.3 +148.5 -96.5

Glyphos

(3.75 pt)

Pre 32.7 0.8 0.2 1.8 11.1 19.0

1 Yr 6.3 2.9 2.4 0.4 12.8 0.5

% Change -80.6 +280.5 +1523.3 -78.2 +15.0 -97.6

Glyphos

(7.5 pt)

Pre 25.8 1.1 0.8 1.8 10.8 14.1

1 Yr 2.3 4.3 2.4 0.4 22.1 0.3

% Change -90.9 +291.9 +183.0 -80.7 +105.8 -98.2

Control

Pre 33.3 1.3 1.8 0.4 7.2 12.0

1 Yr 38.3 9.5 0.2 0.9 2.6 4.9

% Change +15.0 +635.7 -88.1 +112.6 -63.8 -56.5

Ground Cover

% Survival

Swamp bay

Dahoon holly

Wax myrtle Myrsine

Metsulfuron (2 oz) 80.8 82.4 71.2 6.7

Metsulfuron (4 oz) 89.7 79.1 80.5 0.0

Glyphosate 3.75 pt 54.0 85.4 32.0 100.0

Glyphosate 7.5 pt 24.5 52.2 20.8 66.7

Control 100.0 100.0 70.4 100.0

Shrubs / Trees

Conclusions

1. Herbicides (glyphosate, metsulfuron methyl, triclopyr, and imazapic) are effective

2. Tank mixes of these herbicides are acceptable, but lower rates should be used in areas of lower infestations

3. Non-target damage will be unavoidable

4. Regardless of the herbicide or herbicides used, re-treatment will likely be required

QuestionQuestionss