Choosing the Right Treatment
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Transcript of Choosing the Right Treatment
Choosing the Right Treatment
2013 MnPIE RecertificationDale S. Sutherland
CPS Timberland
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
Vegetation Management Plans
A solid Vegetation Management Plan/Strategy can Eliminate the Need for“Mulligans”
Inventory
Inventory SiteNeed to know what you have
– Target SpeciesWhat do you want to control
– Non Target SpeciesWhat species do you want to protect
– Sensitive AreasWetlands/Streams/Lakes etcRare and/or Endangered SpeciesAdjacent Ownership
– Ag fields/gardens– Adjacent vegetation– other
– Soil Type– Other
ID what is important to your site and for your goals/vision
Know the SpeciesTarget and Non Target
Plant CharacteristicsKnow how they tick…..You need this info to develop action plan
– Live CycleAnnualBiennialPerennial
– ReproductionSeedRoot/rhizome
– Habitat/Ecosystem needsUse 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
Desired Future ConditionWhat 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
MechanicalChemical ( We’ll focus here)BiologicalCultural
– Knowledge about the Plants– Knowledge about your tools
How do they work
IVM Toolbox
MechanicalChemicalCulturalBiological
Most treatments will fit in these catagories
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
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
plantSoil active systemic (Tordon, Arsenal, Spike, Perspective)– Absorbed into root system and translocated
throughout the plant.– Pre emergent products are soil active
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
Why understand herbicide MOA?
• Better understanding of how herbicides perform
• The role surfactants play• Diagnosing herbicide injury• Professionalism• Public relations
Mode of Action
For a herbicide to be an effective, it must:
1. Contact the plant surface
2. Remain on the plant surface long enough to be absorbed
3. Reach a cellular site and disrupt a life supporting process or structure
4. Degrade into non-toxic metabolites
Absorption or
Mode of EntryMovement of herbicide through
the cuticle or epidermal root tissue into the plant
Mode of Entry
Primary means by which herbicide is absorbed into a plant.
Three options:• Foliar active • Soil active• Foliar and soil active
Foliar Absorption
Foliar Absorption
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
Translocation Movement of herbicides from
point of entry to the site of action in the plant
• 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.
Translocation
Phloem
Xylem
Phloem mobile (Symplastic) herbicides move upward (acropetal) and downward (basipetal) in the plant
Xylem mobile (Apoplastic) herbicides move up in the plant
Contact herbicides
do not move in plant
Systemic herbicides move (translocated)
Site-of-ActionLocation in plant where herbicide exerts toxicity at the cellular level
Photosynthesis
Amino acid and protein synthesis
Cell division
Growth regulation
Fatty acid synthesis
Mechanism of Action Specific biochemical or
biophysical process in plant that is inhibited by the herbicide
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
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)
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)
Herbicides Commonly Used in Forestry Herbicide Primary mode of action
Chemical name Product name Mode of entry
Type Mechanism
Glyphosate Accord, Roundup Foliage Systemic Amino acid synthesis
Imazapyr Arsenal, Chopper Foliage & soil Systemic Amino acid synthesis
Sulfometuron Oust Foliage & soil Systemic Amino acid synthesis
Triclopyr Garlon 4, Garlon 3a Foliage Systemic Growth regulator
Hexazinone Velpar Foliage & soil Systemic Photosynthetic inhibitor
2, 4-D Weedone, Esteron Foliage Systemic Growth regulator
Metsulfuron Escort, Ally Foliage & soil Systemic Amino acid synthesis
Picloram Tordon Foliage & soil Systemic Growth regulator
Simazine Princep Soil Systemic Photosynthetic inhibitor
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
Chemical PropertiesSoil Persistence– 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 runoffUptake by plants and animalsLeachingVolatilization
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.
Half-life of Common Herbicides
Herbicide Half-life in soil
Glyphosate Short (<1 - 4 wks)
Imazapyr Moderate (1 - 5 mo)
Sulfometuron Short (3 - 4 wks)
Triclopyr Short (4 - 8 wks)
Hexazinone Moderate (1 - 6 mo)
2, 4-D Short (1 - 4 wks)
Metsulfuron Short (1 - 6 wks)
Picloram Moderate -
Long (6 - 12 mo)
Simazine Moderate (3 - 12 mo)
Water Solubility and Mobility of Common Herbicides
Herbicide Water solubility
Mobility in soil
Glyphosate High Negligible Imazapyr High Low
Sulfometuron Low Low - Moderate
Triclopyr Amine - high Ester - low Low
Hexazinone Mod. - high Moderate
2, 4-D Amine - high Ester - low
Low - Moderate
Metsulfuron Moderate - high
Moderate -High
Picloram High High Simazine Low Low
Application MethodsHigh 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
Application MethodsCut Stubble– Soil active products
Tordon, Arsenal, Stalker, etc
– Absorbed thru root systemMust move into root zone
– Unfrozen soilTiming 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
Timing
Brush ControlWoody perennials
– FoliarAt least one growing season on regrowthCritical with root suckering species like AspenActively growingPlants not under stress
TimingWeed Control
Know each target species– Annuals
Early in plant life cyclePrevent seed production/release
– Chemical and/or mechanical– Biennials
Year one: thru out yearYear two: early in season, prevent seed productionWill die in year two
– PerennialsCombo of chemical and mechanical often most effectiveNeed to control root system
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
Tank MixesMechanism of Action– 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
Conclusion
Have a PlanNo “One Best” Treatment– Choose the right tool or combination of
tools/timingMake decisions site by siteKnow your SiteKnow the ToolsKnow the Plants
Questions???
Thank you!!!
Dale SutherlandCPS Timberland218-259-3605