| Herbicide Rate |
- Applied at 0.05 – 0.3 ppm, often in combination with potassium endothall
- Submersed or foliar applications for crested floating heart and hydrilla control
|
| Breakdown / Inactivation |
- Half-life in water about one week or less
|
| Microbial |
- Microbial metabolism is primary degradation pathway
|
| Adsorption |
- Does not adsorb to suspended solids or sediments
|
| Photolysis |
- Does not degrade by photolysis
|
| Hydrolysis |
- Not sensitive to hydrolysis
|
| Dissipation |
- Breaks down fairly rapidly in water so dissipation is minimal
|
| Formulation |
|
| Liquid |
- Available in liquid formulation
|
| Solid |
- Available in granular formulation
|
| Mechanism of Action |
- Unclassified in WSSA Resistance Grouping
- Protein phosphatase inhibitor
|
| Mode of Action |
|
| Systemic |
- Absorbed by foliage or underwater tissues
- Interferes with protein and lipid synthesis
- Disrupts cell membrane and respiration – cell membranes become leaky
- Cell contents spill out – cannot make energy and die
- Somewhat mobile in plant tissues
- Long thought to be contact-type herbicide
|
| Plant Growth Regulator |
- Not used as a plant growth regulator in Florida aquatic plant control applications
|
| Stewardship |
|
| Herbicide resistance |
- Not yet classified in WSSA Resistance Grouping
- No tolerance or resistance issues reported in Florida
- Used occasionally with potassium endothall as a resistance management strategy
|
| Waterbody Parameters | Management Considerations |
|---|
| Hydrology |
|
| Water depth |
- Used as submersed applications to control crested floating heart
- Occasionally used for hydrilla or hygrophila control
- Important to know water depth to calculate appropriate dose
|
| Water volume |
- Used for crested floating heart control in small areas
- Alone or in combination with potassium endothall
- Volume of treated area is essential to calculate appropriate dose
|
| Water movement |
- Need 12-24 hours of exposure for crested floating heart or hydrilla control
|
| Water chemistry |
|
| Dissolved oxygen (DO) |
- Generally, no issues related to this parameter
- Control areas are typically small
- Small amount of plant biomass controlled
|
| pH, alkalinity, hardness |
- No issues related to this tool
|
| Nutrient content |
- No issues related to this tool
- Primarily used for small-scale crested floating heart control
|
| Water transparency |
- Need actively growing plants for herbicide uptake
|
| Sediment characteristics |
|
| Composition |
- Sand / clay – no issues related to this tool
- Organic – no issues related to this tool
|
| Potential for re-suspension |
- Does not adsorb to suspended material
|
| Plant Physiology Parameters | Management Considerations |
|---|
| Plant origin / growth potential |
|
| Native |
- Amine endothall is an algaecide
- Infrequently permitted or used by FWC for this purpose in Florida waters
- Little to no use with this compound for non-native vascular plant management
|
| Non-native |
- Little to no use with this compound for non-native plant management
|
| Invasive
|
- Crested floating heart
- Use alone or at low rates in conjunction with potassium endothall
- Primary control method for crested floating heart
- Follow-up applications may be necessary to control skips
- Alone at 2 qt/acre-foot as subsurface injection
- Apply to actively growing plants late summer (July – August)
- Combination at 0.3 ppm with potassium endothall at 3.0 ppm
- Apply late spring through summer
- Hydrilla
- Spot control new hydrilla infestations with granular formulation
- Boat ramp / isolated spots in canals
|
| Plant growth stage (target/non-target) |
- Need actively growing plants for herbicide uptake
|
| Plant susceptibility (target/non-target) |
- Apply to actively growing target plants
- May control vallisneria when used at higher rates with granular formulation
|
| Potential for regrowth (target/non-target) |
- Hydrilla regrowth depends on extent of control, water clarity and depth
- Regrowth is slower if root crowns are killed – limited to tuber / turion sprouting
- Southern naiad and Illinois pondweed are controlled by endothall
- Usually recover during the same or next growing season
|
| Climate Parameters | Management Considerations |
|---|
| Weather |
Daily
- Need at least 12-24 hours of contact exposure
- Dependent on dose and water temperature
- Windy conditions may increase dissipation in spot or band applications
Seasonally
- Less herbicide may be required in cooler months
- Microbial breakdown is slower so herbicide active for longer period
- Applying to actively growing plants increases uptake
|
| Light intensity |
- No issues related to this tool – not broken down by photolysis
|
| Water temperature |
- Endothall degradation can occur more rapidly in warmer water (> 80°F)
- Could result in reduced efficacy
|
