Management of Brazilian peppertree

(Schinus terebinthifolius) in Florida mangrove

communities.Cody A. Lastinger and Stephen F. Enloe

University of Florida

Department of Agronomy

Center for Aquatic and Invasive Plants

Brazilian Pepper Tree

Brazilian Peppertree

Red MangroveRhizophora mangle

Black MangroveAvicennia germinans

White MangroveLaguncularia racemosa

Buttonwood MangroveConocarpus erectus

Current Strategies Basal Bark Treatment (10-20% triclopyr ester)

Current Strategies Cut stump treatment

(50% Triclopyr amine or 50-100% glyphosate)

2. Loss of herbicide from dead or dying roots 3. Herbicide available in

soil solution

4. Herbicide absorbed by nearby trees

1. Cut stump treatment with triclopyr amine

What may be happening:Herbicide flashback

10,000 IslandsEverglades National

Park

Reality: We need new approaches for safer

treatment and for remote areas!

Objective• To develop selective control strategies for Brazilian

pepper tree growing in mangrove communities• Examine both older and more recently labeled aquatic

herbicides

• Examine herbicide on different Brazilian peppertree life stages

• Examine the impacts of aquatic herbicides on mangrove species

• Large plot/field studies

• Sequential treatments

Methods

• Seedlings – 1 to 2 leaf stage • Plants 3 weeks old from seed

• 90 DAT evaluation • Shoot height and visual injury

• Juveniles ~40 cm tall• Plants 2 months old

• 90 DAT evaluation• Shoot height and visual injury

Methods

• Well established ~75 cm plants• Plants 6 months old

• 90 Day Evaluation• Shoot height and visual Injury

• Shoot biomass (10cm clip height)

Methods

• Mangroves and Buttonwood• 1 gallon pots

• 180 DAT evaluation• Injury (visual assessment)

Methods

• Foliar application• 20 gpa

• Data Analysis• Percent reduction in shoot height and injury

• Multiple comparison using Tukey’s protected LSD p=0.05

Aquatic Herbicides EvaluatedHerbicide Mode of Action Rate kg ai/ha

Glyphosate Amino Acid Inhibitors 0.55

Imazamox Amino Acid Inhibitors 0.138

Bispyribac Amino Acid Inhibitors 0.073

Penoxsulam Amino Acid Inhibitors 0.016

Imazapyr Amino Acid Inhibitors 0.18

Carfentrazone PPO Inhibitors 0.036

Flumioxazin PPO Inhibitors 0.07

triclopyr Auxin Types 0.55

2,4-D Auxin Types 0.367

Fluridone Carotenoid Biosynthesis Inhibitor 0.04

Topramezone Carotenoid Biosynthesis Inhibitor 0.064

Diquat PSI inhibitor 0.73

endothall Not Classified 2.48

Brazilian peppertree, 90 DAT

Glyphosate Imazamox Imazapyr

Brazilian peppertree, 90 DAT

Triclopyr 2,4-D

Brazilian peppertree, 90 DAT

Diquat Flumioxazin on Seedling

Mangroves: Run 1, 180 DAT

Mangroves: Run 2, 180 DAT

Imazapyr on black and red mangrove

Run 1 Run 2

Mangroves: Run 1, 180 DAT

Mangroves: Run 2, 180 DAT

Triclopyr on white and red mangrove

Mangroves: Run 1, 180 DAT

Mangroves: Run 2, 180 DAT

Mangrove sensitivity to Diquat

White Black

Red mangrove sensitivity to Diquat

Conclusions to date• Brazilian pepper tree

• Amino acid inhibitors: Imazamox and imazapyrmost effective treatments and glyphosate was effective on well established plants

• Growth regulators: Triclopyr > 2,4-D

• PPO inhibitors: control decreased as plants became more established, worked well on seedlings

• Carotenoid biosynthesis inhibitors not effective

• PSI inhibitor: diquat provided excellent control but effectiveness decreased as plants became more established

Conclusions to date

• Brazilian pepper tree (cont.)

• triclopyr, imazapyr, and glyphosate demonstrated promise in control of Brazilian pepper tree

• Imazamox was the only newer herbicide to show useful activity

Conclusions to date

• Mangrove• All herbicides that demonstrated efficacy on

Brazilian pepper tree, resulted in injury to at least one of the mangrove species.

• Herbicides that did show great efficacy on Brazilian peppertree, caused injury to some or all of the mangrove species

• All three species of mangrove and buttonwood demonstrated sensitivity to the aquatic labeled herbicides

Red Black White Buttonwood

Glyphosate 47.5 100 100 77.5

Imazamox 60 75 100 95

Imazapyr 100 100 100 100

Triclopyr 100 75 100 100

Injury observed on Mangroves from Herbicides that were effective on well

established Brazilian peppertree

Next Steps

• Examine herbicides that may gain aquatic registration and tank mixes

• Field experiments

• Individual plant treatments

Acknowledgements

• FWC

• Dr. Enloe

• Students and staff at the CAIP

Questions?

clastinger@ufl.edu