forestry herbicides 101

Matt KrausharHabitat Restoration and Ecology Purdue University West Lafayette, IndianaDepartment of Forestry and Natural

Resourcesmkrausha@purdue.edu

Topics

Integrated Vegetation Management Techniques

More than one way to apply herbicide!Site Prep- plantations and under planting

Resistance Invasive and Exotic Species

ID and Control

“Many Hammers” – Liebman & Gallandt 1997.

The most successful habitat and vegetation management plans require adaptive strategies:

Integrated Vegetation Management (IVM)

IVM

DesiredVegetation

AvailableMethods

Long-termmaintenance

Vegetation Management Options

Chemical - use of any herbicide/pesticide

Mechanical - physical attack on the plant

Natural - competition*, drought, fire, etc.

Biological - purposeful release of a predatory organism

IVM- combinations of the above

Biological Control

Mechanical

Herbicide as a tool

Year-round/Dormant Season Method(e.g. thinning and TSI)

Dormant season methods help to reduce non-target impacts & extends your spray season.

BasalTreat starting at the height of 18 in. ringing stem, herbicide and oil mixture should spread covering to the root collar (Gravity is your friend!)

Cut-surfaceTreat the cross sectional area of the cambium layer at the root collar 1-3 in above the ground.

Hack and squirtUse of modified axe to cut into the tree creating pockets for herbicide delivery

GirdlingMechanical ringing of the tree to kill above ground portion of the tree.Treating cambium layer only ups your chances for control.

Cut surface Herbicide Applications

Basal herbicide applicatoin

A high quality basal oil will help spread the mix to cover much of the stem, but be sure to cover entire stem!

Basal & cut-surface methodsThese methods can be used nearly year round.

Mechanical removal alone won’t provide control for many problematic species.

Mortality unaffected by size.

Garlon 4(20%)+ Ax-it(80%), Garlon 4(20%)+ Stalker(3%) + Ax-it(77%), Garlon 4(15%) + Stalker(3%) + Ax-It(82%) all provide excellent control

Operational differences in test trials suggest Garlon 4 (15%) + Stalker (3%) + Ax-It (82%) is the best choice.

Using products and application methods designed specifically forwoody vegetation provides exceptional levels of control when used carefully and correctly.

Hack and Squirt applications

Effective method but:SlowLabor intensive Thorns/branchesLimited to late winter and summer High densities decrease efficiency

Equipment for basal, cut surface and hack and squirt methods

Aerial applications

Precision guided helicopter spray rigs Or send your crew workers in!

Broadcast Foliar ApplicationsBroadcast Foliar ApplicationsBroadcast Foliar Applications

Wide Cast nozzles for low volume ATV spraying

Foliar treatment experiences

Glyphosate, Imazapyr, and metsulfuronherbicides provide good control of woody species during the late summer and fall spray window.Waiting 1.5 or 2.5 years after mowing to initiate foliar brush treatments is not necessary……Furthermore, waiting increases the presence of other undesirable plant species.

Low Volume and Ultra Low Volume Back Pack ApplicationGreat for Selective Plant Control in Sensitive areas.

Herbicides function as….

A disturbance…… is that good or bad?

They can be selective by species, plant group, or application method. Thus they can be used to shape successionalpatterns within a complex of vegetation.

Mode of action or biochemistry and application method determine impact

Be creative with your sprayer designs to meet your application needs

Herbicide Stewardship

Importance and necessity of calibration.Function of time, area and volume. Every sprayer needs calibrated regularly.

Mindful of surroundings. Don’t contaminate local water systems.Drift- many of the products used in forestry don’t get along with crops and gardens.

Following the label- THE LABEL IS LAW!

Calibrate Regularly !

24 oz 14 oz

Site Prep – Weed Control

Mow in mid July and again in mid August.Broadcast herbicide

Glyphosate - Roundup, GlyproPlus.Apply in fall – September to early October

Not during dry period – need active growth.On slopes where erosion is a concern, spray herbicide in 3 to 4 feet-wide bands in the tree planting rows. Some hard-to-kill undesirable brush and tree species may require other herbicides to kill them

Site PreparationDeal with competing vegetation before planting. Particularly important with perennial grasses and broadleaves.

Bare Ground vs Cover CropBare ground yields the best tree growth rates, but can be expensive to maintain.Cover crops may aid in managing weed growth but can reduce tree growth rates.

Post-Planting Care –Weed Control First 3 – 5 Years is important

Post-Planting Care –Weed Control

Good Weed Control

Poor Weed Control

Adequate Weed Control Makes a Difference

3 - 4 growing seasons

Weed Control – Chemical options

Pre-emergent Herbicides Follow the label and calibrate regularly.○ Simazine - Princep○ Pendimethalin - Pendulum○ Oryzalin - Surflan ○ Sulfometuron – Oust

Post-emergent Herbicide○ Glyphosate - Roundup, GlyproPlus○ Transline

Importance of tank mixing

Well that’s just how we do it…

Just because that’s how you always do it…

Doesn’t mean it’s the RIGHT

WAY!!

0

50

100

150

200

250

1950 1960 1970 1980 1990 2000

Year

Num

ber o

f Res

ista

nt B

ioty

pes

Development of Resistant Weeds

Compatible Modes of ActionSome herbicides may not be compatible due to antagonistic MOA’s.

Ex. 2,4-D + RoundUp, Garlon + Arsenal, Krenite and Accord

Amino Acid and Bud Inhibitor herbicides have complimentary activity.

Ex. Krenite + Escort and/or Powerline

Having more than 1 compatible mode of action in the tank is often preferable. WHY ?

Why use more than one mode of action (chemical tool) in the tank mix?

Change up the tank mix.

If weed management programs don’t diversify or alternate chemistries (MOA) than problems with resistance can occur.What are weeds?

Specific speciesGroups of speciesDiverse assemblage of species, groups, and populations. Adaptable? - YES

A population of a single weed species all looks the same, but…

Seedling weeds represent multiple generations of seed production.

Detection of Resistant Weeds-Visual

History of using single herbicide mechanism of action for extended periodOnly one species Other species controlledSpecies was previously controlledPresence of resistant populations in area

Beware in areas that were prior row crop!!!Spotty population not being controlled while others are.

Practices Leading to Resistance

Use of same herbicide for multiple yearsUse of a single herbicide (no mixtures)Use of long-residual herbicidesUse of highly active herbicides aloneDepending on herbicides alone for weed controlPresence of highly sensitive, highly variable species (ex. mares tail, Johnsongrass, foxtail)

Resistance doesn’t just happen-

It is a product of VM practices.It is a product of VM practices.

Summing up resistance…

Herbicide resistance is selected through continuous (miss) use of same herbicide.Resistance can be managed with use of herbicide rotations and tank mixtures.Resistance is most likely to cause problems on forest edges, early regenerations, and in tree plantings.When in doubt, assume resistance and treat accordingly.

If we learn to avoid creating VM problems, life would be easier.

Invasive and Exotic Species

Definitions:

Invasive plant - any plant that is unwanted and grows or spreads aggressively.

Exotic species – a species that occurs outside of the eco-geographical area where it evolved.

So what is wrong with invasive species?Invasive species have the ability to:

Spread rapidly Adapt readily to the environmentPersist and negatively alter ecosystems Cost $ $ $ to manage and by reducing production

Invasive species don’t stop at the edge of the woods or at the creek.

Their aggressive nature results in management practices that can be difficult, especially in highly infested areas.

How do we control them?Like all plants, invasive species react to management in both positive and negative ways.

Some methods actually promote their growth giving them a competitive advantage….

They become an management issue when:1) they establish 2) they out-compete native species 3)you have to create a plan to manage them!

Yellow =Exotic

BLUE =Native

Yellow =Exotic

BLUE =Native

Ailanthus altissima –ailanthustree‐of‐heaven

Tree of Heaven - Foliar SprayCommon Name Example Brand

NamesComments

glyphosate Roundup, Accord, many others

Apply 2% vol/vol solution in water when leaves active; surfactant if not in herbicide.

triclopyr Garlon 3A, Tahoe 3A

2% vol/vol solution in water when leaves active

triclopyr Garlon 4, Garlon 4 Ultra, Tahoe 4E, Remedy

1.5% vol/vol solution in water when leaves active

metsulfuron methyl Escort XP 1-2 oz/A or 1 gm/gal

ammonium salt of fosamine

Krenite S 30% vol/vol solution

fosamine + metsulfuron methyl

Krenite S + Escort XP

1.5-3 gal/A Krenite S + 1-2 oz/A Escort XP

Tree of Heaven – Basal SprayCommon Name Example Brand

NamesComments

triclopyr Garlon 4, Tahoe 4E, Remedy, Garlon 4 Ultra

15-20% in basal oil.

triclopyr Pathfinder II RTU formulation, do not dilute.

imazapyr Stalker, Chopper 8-12 oz in gallon of penetrating/basal oil.

triclopyr + imazapyr Garlon 4 + Stalker or equivalent

15-20% Garlon 4 + 3-5% Stalker in penetrating/ basal oil.

Tree of Heaven – Cut StumpCommon Name Example Brand

NamesComments

glyphosate Roundup, Accord, many others

Dilute with water to no less than 20% active ingredient.

triclopyr Garlon 3A, Tahoe 3A Apply full strength as would a water carried herbicide.

triclopyr Garlon 4, Tahoe 4E,Remedy, Garlon 4 Ultra

20% in basal oil.

triclopyr Pathfinder II Apply full strength as would an oil carried herbicide.

imazapyr Stalker, Chopper 8-12 oz. in a gallon penetrating/basal oil.

Imazapyr

triclopyr + imazapyr

Arsenal

Garlon 4 + Stalker or equivalent

8-12 oz. in a gallon of water

15-20% Garlon 4 + 3-5% Stalker in penetrating/ basal oil.

AMUR

HONEYSUCKLE(Lonicera maackii)

Bush Honeysuckle – Foliar SprayCommon Name Example Brand

NamesComments

glyphosate Roundup, Accord, and others

Apply 2% vol/vol water solution or 3-4 qts/A; surfactant if not in herbicide.

2,4-D + triclopyr Crossbow Wet foliage and stems with 1-1.5 gallons Crossbow in 100 gallons water; spot spray with 0.25 pt (½ cup) Crossbow in 3 gallons water.

triclopyr Garlon 3A, Tahoe 3A Apply 3-5% vol/vol water solution.

metsulfuron methyl Escort XP Apply 1-2 oz/100 gallons water + nonionic surfactant or 1 gm/gallon water plus surfactant.

Common Name Example Brand Names

Comments

triclopyr Garlon 4, Tahoe 4E, Remedy, Garlon 4 Ultra

15-20% in basal oil.

triclopyr Pathfinder II RTU formulation, do not dilute.

imazapyr Stalker, Chopper 8-12 oz in gallon of penetrating/ basal oil.

triclopyr + imazapyr Garlon 4 + Stalker or equivalent

15-20% Garlon 4 + 3-5% Stalker in penetrating/ basal oil.

Bush Honeysuckle – Basal Spray

Common Name Example Brand Names

Comments

glyphosate Roundup, Accord, many others

Dilute with water to no less than 20% active ingredient.

triclopyr Garlon 3A, Tahoe 3A Apply full strength as would a water carried herbicide.

triclopyr Garlon 4, Tahoe 4E,Remedy, Garlon 4 Ultra

20% in basal oil.

triclopyr Pathfinder II Apply full strength as would an oil carried herbicide.

imazapyr Stalker, Chopper 8-12 oz. in a gallon of penetrating/ basal oil.

imazapyr

triclopyr + imazapyr

Arsenal (Powerline)

Garlon 4 + Stalker or equivalent

8-12 oz. in a gallon of water

15-20% Garlon 4 + 3-5% Stalker in penetrating/ basal oil.

Bush Honeysuckle – Cut Stump

Autumn Olive

(Elaeagnus umbellata)

Common Name Example Brand Names

Comments

glyphosate Roundup, Accord, many others

Apply 2% vol/vol solution in water when leaves active; surfactant if not in herbicide.

triclopyr Garlon 3A, Tahoe 3A

2% vol/vol solution in water when leaves active

triclopyr Garlon 4, Garlon 4 Ultra, Tahoe 4E, Remedy

1.5% vol/vol solution in water when leaves active

metsulfuron methyl Escort XP 1-2 oz/A or 1 gm/gal

ammonium salt of fosamine

Krenite S 30% vol/vol solution

fosamine + metsulfuron methyl

Krenite S + Escort XP

1.5-3 gal/A Krenite S + 1-2 oz/A Escort XP

Autumn Olive – Foliar Spray

Autumn Olive – Cut Stump SprayCommon Name Example Brand Name Comments

glyphosate Roundup, Accord, and others Apply 20% a.i. glyphosate in water to outer third of cut stem/stump surface immediately after cutting (timing critical).

triclopyr Garlon 3A, Tahoe 3A Apply full strength as would a water carried herbicide.

triclopyr Garlon 4, Tahoe 4E, Remedy, Garlon 4 Ultra

20% in basal oil.

triclopyr Pathfinder II Apply full strength as would an oil carried herbicide.

imazapyr Chopper, Stalker 8-12 oz. in a gallon of penetrating/ basal oil.

2,4-D + triclopyr Crossbow 4% Crossbow with 96% penetrating/ basal oil.

picloram + 2,4-D Tordon RTU, Pathway

Tordon 101

Apply full strength as would a water soluble herbicide.Apply Tordon 101 diluted 1:1 with water.

Common Name Example Brand Names

Comments

triclopyr Garlon 4, Tahoe 4E, Remedy, Garlon 4 Ultra

15-20% in basal oil.

triclopyr Pathfinder II RTU formulation, do not dilute.

imazapyr Stalker, Chopper 8-12 oz in gallon of penetrating/ basal oil.

triclopyr + imazapyr Garlon 4 + Stalker or equivalent

15-20% Garlon 4 + 3-5% Stalker in penetrating/ basal oil.

Autumn Olive – Basal Spray

Multiflora rose(Rosa multiflora)

Alliaria petiolata – garlic mustard

Garlic Mustard – Foliar Spray

Common Name Example Brand Names

Comments

glyphosate Roundup, Accord, and others

1-2% vol/vol in water; surfactant if not in herbicide.

triclopyr Garlon 3A, Tahoe 3A 2% vol/vol

Lonicera japonica –Japanese honeysuckle

Microstegium vimineum ‐Japanese stilt grass

ED & RR

Prevention is easier!

Herbicides are prevention and protectionwhen they are included in an IVM plan.

Even the toughest, most heavily invaded, sites can be tamed!!

Month 0 : mechanical biomass reduction

Months 1-8 : woody invasive plants re-grow

• 90.4% of the woody plant re-growth was invasive.

Month 8 : Plant re-growth is sprayed during early fall. (4 herbicide treatments)

3 months after planting

Vegetation management Vegetation management must be done CAREFULLY!!must be done CAREFULLY!!

Top 10 Forest Invasive      Plants

A Landowner’s GuideComing Soon!!!

Zach Lowe & Sally WeeksForestry and Natural Resources

Purdue University

A sincere Thank You to…

Especially thank you to Dr. Weeks (Purdue University), Dr. Lowe (Purdue University), Lenny Farlee (Purdue University), Greg Ressler (Townsend Chemical Division), Dr. Heiligmann (Ohio State University) and Mitch Blair (University of Kentucky) for the mentoring and contributions to the creation of this presentation.

We are here to help…..I think.

Please take a kid hunting or fishing…. They are our future!!

Questions?mkrausha@purdue.edu