1. Choosing the Right Treatment
2013 MnPIE Recertification
Dale S. Sutherland
CPS Timberland

2. Managing Sites, Not Just Treating Them
Vegetation Management
Seldom a one shot treatment
Converting vegetation types over time
Usually fighting natural succession
On going battle
Use all the tools
Know What You Have
Inventory
Know What You Want
Desired Future Condition
Vision
Know How to Get There
IVM Plan
Know your toolbox

3. Vegetation Management Plans
A solid Vegetation Management Plan/Strategy can Eliminate the Need for “Mulligans”

4. Inventory Inventory Site Target Species Non Target Species
Need to know what you have
Target Species
What do you want to control
Non Target Species
What species do you want to protect
Sensitive Areas
Wetlands/Streams/Lakes etc
Rare and/or Endangered Species
Adjacent Ownership
Ag fields/gardens
Adjacent vegetation
other
Soil Type
Other
ID what is important to your site and for your goals/vision

5. Know the Species Target and Non Target
Plant Characteristics
Know how they tick…..
You need this info to develop action plan
Live Cycle
Annual
Biennial
Perennial
Reproduction
Seed
Root/rhizome
Habitat/Ecosystem needs
Use of classification systems (ECS, Habitat Type, Biophysical, Soil type, etc)
Helps you predict what is likely to show up following mgmt activities
Moisture
Light
Etc

6. Desired Future Condition
What do you want it to look like?
Native Grass/Prairie
Red Pine Stand
Grassy Powerline R/W
How do you get there?
Here is where the IVM toolbox comes in
Mechanical
Chemical ( We’ll focus here)
Biological
Cultural
Knowledge about the Plants
Knowledge about your tools
How do they work

7. IVM Toolbox Mechanical Chemical Cultural Biological
Most treatments will fit in these catagories

8. Herbicide Classifications (Products can fall into multiple categories)
Selective
Controls only certain types of plants
Broadleaf herbicides such as Garlon, Tordon, Escort
Non Selective
Will damage or control most plants
Rodeo, Roundup, Arsenal
Rate dependant
Systemic
Translocated throughout the plant
Garlon, Tordon, Arsenal, Escort, Rodeo
Contact
Controls only the portion of the plant that is treated
Krenite

9. Herbicide Classifications (Products can fall into multiple categories)
Pre Emergent (Oust XP, Diuron, Krovar, Evade)
Controls plant growth at germination
Emergent (Most products used in VM and Forestry)
Controls plants after germination
Foliar Systemic (Garlon, Escort, Tordon, Arsenal, Streamline)
Applied to top growth and translocated throughout the plant
Soil active systemic (Tordon, Arsenal, Spike, Perspective)
Absorbed into root system and translocated throughout the plant.
Pre emergent products are soil active

10. Mode of Action
Defined: The entire chain of events from first contact of the herbicide to the final effect on the plant.
Absorption
Translocation
Site-of-Action
Mechanism-of-Action

11. Why understand herbicide MOA?
Better understanding of how herbicides perform
The role surfactants play
Diagnosing herbicide injury
Professionalism
Public relations

12. Mode of Action For a herbicide to be an effective, it must:
Contact the plant surface
Remain on the plant surface long enough to be absorbed
Reach a cellular site and disrupt a life supporting process or structure
Degrade into non-toxic metabolites

13. Absorption or Mode of Entry Movement of herbicide through the cuticle or epidermal root tissue into the plant

14. Mode of Entry
Primary means by which herbicide is absorbed into a plant.
Three options:
Foliar active
Soil active
Foliar and soil active

15. Foliar Absorption

16. Foliar Absorption

17. Mode of Entry Soil active – absorbed by roots
Herbicides applied to soil surface move within top 1 to 4 inches
Herbicides must move in the soil solution, so require soil water to be activated in soil
May require greater concentrations than foliar applied herbicides because of the great volume of soil
Individual products affinity to adsorb to soil plays a role
Soil structure is important, texture, organic content, etc

18. Translocation Movement of herbicides from point of entry to the site of action in the plant

19. Translocation
Phloem - living tissue that transports sugars from the site of synthesis or storage to the site of use.
Xylem - nonliving tissue in a plant that transports water and mineral nutrients from the roots to the shoots.
Phloem
Xylem

20. Contact herbicides do not move in plant
Phloem mobile (Symplastic) herbicides move upward (acropetal) and downward (basipetal) in the plant
Xylem mobile (Apoplastic) herbicides move up in the plant
Systemic herbicides move (translocated)

21. Site-of-Action Location in plant where herbicide exerts toxicity at the cellular level

22. Amino acid and protein synthesis
Photosynthesis
Fatty acid synthesis
Cell division
Growth regulation
Amino acid and protein synthesis

23. Mechanism of Action Specific biochemical or biophysical process in plant that is inhibited by the herbicide

24. Herbicides Classified by Their Mechanism of Action
Photosynthesis
Amino acid and protein synthesis
Cell division
Cell membranes
Pigment synthesis
Growth regulation
Growth inhibition
Fatty acid synthesis

25. Mechanisms of Action
1. Acute toxicity – rapid kill of plant tissue by causing cell rupture, not translocated, non-systemic, contact herbicides (e.g., such as paraquat, diquat, sulfuric acid, and petroleum oils)
2. Chronic toxicity – kills slowly through chronic toxicity, systemic
3. Hormone or growth regulation - disruption of transport systems and interference with nucleic acid metabolism, systemic, affects broadleaves and not grasses (e.g., 2,4-D, triclopyr, picloram, dicamba)
4. Disrupt cell division – inhibits mitosis (e.g., asulam, trifluralin)

26. Mechanisms of Action
5. Inhibit pigment synthesis – disrupts formation of carotinoids and chlorophyll (e.g., oxyflorfen)
6. Inhibit photosynthesis and ATP formation – disrupts electron transport system (e.g., triazines)
7. Inhibit formation of lipid or wax – alters fatty acids and disrupts chloroplasts and mitochondria (e.g., fluazifop, sethoxydim)
8. Inhibit synthesis of amino acids – disrupts acetolactate synthase and production of branched-chain amino acids (e.g, imazapyr, sulfonylureas) or shikimic acid pathway (not found in animals) and production of aromatic amino acids (e.g., glyphosate)

28. Mechanisms of Action Why do we need to know Mechanism of Action
Herbicide Resistance
Multiple Modes reduce chance of building population of resistant plants
Tank mixes
Broadens spectrum of control

29. Chemical Properties Soil Persistence Mobility
Half life varies by product and impacted by many factors i.e. soil pH, moisture, temperature, organic content, microbial activity
Mobility
How readily a compound moves from one ecosystem compartment to another
Factors influencing mobility
Adsorption to soil particles
Surface runoff
Uptake by plants and animals
Leaching
Volatilization

30. Persistence How long a chemical remains intact in the environment.
Measured by half-life or time required for one half of an initial amount to be degraded.
Herbicides must be persistent in the environment long enough to be absorbed and translocated by plants.
Soil-active herbicides need to be more persistent than foliar-active herbicides.
The more persistent a chemical is, the more likely it is to move off site and cause a problem.
Herbicides registered for ROW and forestry have short to moderate persistence.

31. Half-life of Common Herbicides

32. Water Solubility and Mobility of Common Herbicides

33. Application Methods High Volume Foliar (Typically > 25 gals/acre)
Most effective when target species densities are high
Allows for canopy penetration
Foliar and soil active products
Run off reaches soil surface
Low Volume Foliar (Typically < 25 gals per acre)
Effective for lower density target species
Use a good surfactant
Some products work well with low volume applications
Rodeo works well with low volumes
Coverage of the growing points on plant
Less run off to soil
Useful when desirable/sensitive plants below canopy

34. Application Methods Cut Stubble Cut Stump/Basal Soil active products
Tordon, Arsenal, Stalker, etc
Absorbed thru root system
Must move into root zone
Unfrozen soil
Timing can be anytime soil is not frozen
Cut Stump/Basal
Typically oil based carrier
Oil needed to penetrate bark
Fresh cut stump can use water based

35. Timing Brush Control Foliar Woody perennials
At least one growing season on regrowth
Critical with root suckering species like Aspen
Actively growing
Plants not under stress

36. Timing Weed Control Annuals Biennials Perennials
Know each target species
Annuals
Early in plant life cycle
Prevent seed production/release
Chemical and/or mechanical
Biennials
Year one: thru out year
Year two: early in season, prevent seed production
Will die in year two
Perennials
Combo of chemical and mechanical often most effective
Need to control root system

37. Use Rates Label Recommendations Label use rates tend to be broad
Label covers entire U.S.
Use past experience as a guide to local rates
Review past treatments to evaluate use rates
Low end rates will produce less consistent results
Higher rates help make up for inconsistencies in site and climatic conditions
Don’t overlook the value of adjuvants

38. Tank Mixes Mechanism of Action Weed Tolerance Target Species Mix
Discussed Earlier
Multiple Mechanisms of action
Especially on tough to control species
Weed Tolerance
Rotate Treatments
Target Species Mix
Use more than one product to broaden spectrum
Ex: Milestone plus Escort (Opensight)
Desired Future Condition
Extended control vs short term control
Ex: Rodeo and Oust XP
Oust XP extends herbaceous control

39. Conclusion Have a Plan No “One Best” Treatment
Choose the right tool or combination of tools/timing
Make decisions site by site
Know your Site
Know the Tools
Know the Plants

40. Questions???
Thank you!!!
Dale Sutherland
CPS Timberland