Safe and Effective Use of Herbicides for Melaleuca Control

Ken Langeland

UF/IFAS Agronomy Department

Center for Aquatic and Invasive Plants

• Safety– Personal protection– Environmental

• Non-target vegetation

• Wildlife

• Effectiveness– Application technique– Herbicide selection

Per

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ion

Equ

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ent Eye protection

Long sleeves

Chemical resistant gloves

Follow label PPE instructions!

MethodsOf

Application

Hack and Squirt

Cut Stump

Foliar

Imazapyr Terrestrial: Arsenal

Aquatic: Habitat

Foliar, Stump, Hack and Squirt

Hexazinone Velpar L, Velpar ULW Soil

Glyphosate Terrestrial: Roundup, Glyphos, Glypro plus

Aquatic: Rodeo, Glypro, Aquapro, Aquamaster, Aquaneat

Foliar (+ imazapyr)

Stump, Hack and Squirt (+ imazapyr),

Triclopyr amine Terrestrial: Garlon 3A

Aquatic: Renovate 3

Stump

Triclopyr ester Garlon 4 Stump

Imazapic Plateau Foliar

Herbicides Used for Melaleuca Control

Active Ingredient Brand Name(s) Application Method

Inactive xylem

Active xylem

Cambium and phloem

Bark

Woody Stems

Cut Stump Applications

• Cut as close to ground as possible

• If possible cut stumps level!

• Concentrate herbicide just inside bark

• Treat entire circumference

• Use dyes to keep track of what’s been treated

• Treat within 15 minutes of cut

Hack and Squirt• Cut all the way around stem

• Cut all the way in to cambium

• Apply herbicide to exposed cambium

• Use dyes

• Treat within 15 minutes of cut

Foliar Application

• Mature leaves very leathery

• Most herbicides will not penetrate

• Surfactants very important

Bobwhite quail Laboratory Rat

Glyphosate >4,640 4,300

Hexazinone >10,000 1,690

Imazapic >2,150 >5,000

Imazapyr >5,000 >5,000

Triclopyr amine >10,000 2,574

Triclopyr ester 9,026 1,581

Caffeine 192

Acute Toxicity

The lower the number, the higher the toxicity (i.e., it takes a smaller amount to cause toxicity)

Herbicide Behavior in Soil

Root Uptake Half-life MobilityGlyphosate None 47 days Bound

Hexazinone High 90 days High

Imazapic Moderate 120 days Moderate

Imazapyr High 25-142 days Moderate

Triclopyr Low 30 days Moderate

• Current Control – Aerial w/ 3qt Arsenal + 3qt

Rodeo + 4 MSO– Girdle w/ 25% Arsenal + 25%

Rodeo, 50% Arsenal– Cut-stump w/ 25% Arsenal

Prairie Pines

Treated 1/05

Holiday Park

Treated 3/05

US Sugar

Treated 1/05

Arsenal + Rodeo

3 qt + 3 qt 80 80 95

Rodeo

7.5 pt 0 <50 x

Garlon 3 A

3 qt 50 <50 65

Velpar

8 qt 99 60 x

Plateau

12 oz 99 x x

Aerial Herbicide Applications to Melaleuca at TAME Demonstration Sites

Estimated percent control

Prairie Pines Holiday Park US Sugar

Arsenal + Rodeo

25% + 25% 95 100 100

Rodeo 100% 95 99 100Arsenal 100% 95 100 100

Hack and Squirt Herbicide Treatments at TAME Demonstration Sites

Estimated percent control

Prairie Pines Holiday Park US Sugar

Arsenal + Rodeo

25% +25%100 85 100

Rodeo 100% 99 50 95Arsenal 100% 100 95 100Garlon 3A 100% 95 80 100

Cut Stump Herbicide Treatments at TAME Demonstration Sites

Estimated percent control

Treatment Lee 1 Lee 2 Broward

Garlon 3A 5% 100 70 70

Garlon 3A 20% 100 90 70

Brush-B-Gon 100 80 90

Brush Killer 100 90 90

Garlon 3A 50% 100 100 50

Garlon 3A 100% 100 90 70

Roundup SC 25% 100 80 60

Roundup SC 50% 70 100 100

Roundup SC 100% 100 100 100

Arsenal 25% 100 100 100

Untreated 0 50 20

Results: Mortality (%) of melaleuca stumps

Herbicide Labor Total

Arsenal + Rodeo

25% +25%2,166 3,192 5,358

Rodeo 100% 284 3,192 3,476Arsenal 100% 1,708 3,192 4,900Garlon 3A 100% 436 3,192 3,628Arsenal + Rodeo

25% + 25% 921 1,466 2,387

Rodeo 100% 688 1,466 2,154Arsenal 100% 968 1,466 2,434

Herbicide Treatment Costs ($/acre) for Cut stump (shaded) and Hack and Squirt

Conclusions• Roundup SC best homeowner recommendation• Brush-B-Gon, Brush Killer provide adequate control for

homeowners• Arsenal (>25%) provides most consistent results• To minimize non-target damage

– Cut close to ground and level– Apply 50-100% Rundup solution– Put enough (?) on

• Cost comparison (per gallon)– Arsenal $260– Garlon 3A $65– Roundup $20– Rodeo $40

Slanting cuts reduce control with glyphosate

Cut as short as possible for best control with glyphosate

This is difficult to walk in ------- and dangerous

Non-target damage can be site specific!

Questions?