Aquatic Herbicides. AQUATICS WORKSHOP INVASIVE SPECIES ID and MANAGEMENT. Jim Petta, Valent

Transcription

1 Aquatic Herbicides AQUATICS WORKSHOP INVASIVE SPECIES ID and MANAGEMENT Jim Petta, Valent 1

2 Objectives Why aquatic herbicides? What are they? Herbicide classes and Key examples Selecting the right tool 2

3 Flood Control and Water Delivery 3

4 Protection of Wildlife Habitat 4

5 Water Use: Hunting? Fishing? Skiing? 5

6 Invasive Species Which Destroy Ecosystem 6

7 Human Life Impacts Waterways There are essentially almost no natural areas in the world (without humans) Humans have impacted waterways wherever they live including Florida long before Europeans arrived (Mexico City, others) Natural means to manage unnatural impacts are limited at best 7

8 Why Aquatic Herbicides? Because they work Cost effective Efficient Protect water resource Minimal risk to the user and the environment 8

9 Pretreatment (cabomba, Highlands County) 9

10 7 DAT 10

11 30 DAT Clipper applied at 200 ppb 11

12 Duckweed, pretreatment 12

13 14 DAT 13

14 What are Aquatic Herbicides? Organic chemicals which are highly effective at low doses in controlling or managing target plant species Very limited in number due to high barrier to entry (environmental, toxicology, efficacy) Selective tools for aquatic plant managers to protect, maintain, or enhance water resources Are herbicides selective or non-selective? Why or why not? 14

15 Common Myths about Aquatic Herbicides True or False? Aquatic herbicides are toxic to fish Aquatic herbicides are toxic to people.. Aquatic herbicides make our water unsafe to drink. Aquatic herbicides are all the same.. 15

16 How Do We Know if they are Safe to Use? All herbicides must be registered by the USEPA and deemed to offer more benefit than the risk involved in their use (risk/benefit; not precautionary principle). No action is without risk; so according to EPA, nothing is safe. Tools have degrees of risk; it is the aquatic plant manager who manages this risk/benefit No product is allowed for use in Florida waters until registered by the State following USEPA registration; again reviewing the data package. 16

17 Toxicology= The dose makes the poison Herbicides are labeled at doses that are effective without unacceptable toxicities to non-target plants or animals Rate ranges allow managers flexibility to manage target situations depending on lake/pond conditions Labels are written to the dosage/exposures Go off the label, all the toxicity data are no longer relevant The label is written to protect you and the environment and to direct the optimal method of use for the product 17

18 Risk/Benefit or Precautionary Principle? Risk/Benefit Risk: Car wreck Traffic jam CEU s Meeting was important Donuts and coffee Precautionary Car wreck Traffic jam Meteor strike Atomic war Car jacking Others? Which must be listed. No benefit measurement So why would you drive anywhere? 18

19 What Makes Herbicides Work? Active plant growth Good growing conditions Non-stressed from injury, weather, etc. Young, new growth usually most susceptible Direct activity depends on mode of action by class 19

20 Herbicide Classes HRAC Group Mode of Action Chemical Family Active Ingredient Key Brand(s) B Inhibition of acetolactate synthase ALS (aceto hydroxy acid synthase AHAS) sulfonylureas bensulfuron-methyl imidazolinones imazamox ClearCast imazapyr Habitat triazolopyrimidines penoxsulam Galleon pyrimidinyl (thio) benzoates bispyribac-na Tradewind D Photosystem I electron diversion bypyridiliums diquat Reward E Inhibition of protoporphyrinogen oxidase (PPO) N-phenylphthalimides flumioxazin Clipper F1 triazolinones carfentrazone-ethyl Stingray Bleaching: Inhibition of carotenoid biosynthesis at the phytoene desaturase step (PDS) not classified fluridone Sonar G Inhibition of EPSP synthase glycines glyphosate Rodeo O Action like indole acetic acid (synthetic auxins) phenoxy-carboxylic acids 2,4-D multi. pyridine carboxylic acids triclopyr Renovate Z unknowns dicaroboxylic acids endothal Aquathol 20

21 ClearCast Specifications Active Ingredient: imazamox Herbicide Family (Chemical Class): imidazolinones Mode of Action: acetolactate synthase (ALS) inhibitor Key Points: Slow, systemic Regulatory at use rates; plant death? Exempt from tolerances Wild taro, Chinese tallow 21

22 Habitat Specifications Active Ingredient: imazapyr Herbicide Family (Chemical Class): imidazolinones Mode of Action: acetolactate synthase (ALS) inhibitor Key Points: Slow systemic (requires long contact time) Excellent on marginal and floating plants Little to no submersed activity Tough grasses: torpedo and Trop. American WG 22

23 Galleon Specifications Active Ingredient: penoxsulam Herbicide Family (Chemical Class): triazolopyrimidines Mode of Action: acetolactate synthase (ALS) inhibitor Key Points: Slow systemic (requires long contact time) Excellent on Hydrilla, others Controls fluridone resistant Hydrilla Selectivity to non-targets must be managed 23

24 Tradewind Specifications (New in 2011) Active Ingredient: bispyribac Herbicide Family (Chemical Class): pyrimidinyloxybenzoic acid Mode of Action: acetolactate synthase (ALS) inhibitor Key Points: Slow systemic (requires long contact time) Excellent on Hydrilla Highly selective for Southern naiad Controls fluridone resistant Hydrilla Selectivity to non-targets must be managed 24

25 Sonar Specifications Active Ingredient: fluridone Herbicide Family (Chemical Class): not classified Mode of Action: Bleaching by the inhibition of carotenoid biosynthesis at the phytoene desaturase step (PDS) Key Points: Slow systemic (requires long contact time) Excellent on shydrilla, EWM, watermeal, others Highly selective via dose Documented Hydrilla resistance/tolerance in Florida Non-flowing water 25

26 Rodeo Specifications Active Ingredient: glyphosate Herbicide Family (Chemical Class): glycines Mode of Action: Inhibition of EPSP synthase Key Points: Medium speed systemic Excellent on cattail, floating and marginal plants No submersed activity 26

27 Clipper Specifications (New in 2011) Active Ingredient: flumioxazin Herbicide family: N-phenylphthalimides Mode of Action: Initiates cell membrane disruption by protoporphyrinogen oxidase (PPO) inhibition Key points: Fast acting contact Controls both floating and submersed plants Short half life related to ph (alkaline hydrolysis) 27

28 Clipper Environmental Fate Short half life Flumioxazin Aquatic Plant Management ph 5: days Hydrolysis ph 7: hours ph 9: minutes Clipper quickly dissipates from the water column; does not accumulate in soil sediment 28

29 Reward Specifications Active Ingredient: diquat Herbicide family: Bipyridiliums Mode of Action: Photosystem I electron diversion (cell membrane disruption) Key points: Fast acting contact Controls both floating and submersed plants High binding to clay lattice 29

30 Aquathol Specifications Active Ingredient: endothall Herbicide family: Dicarboxylic acid Mode of Action: Unknown/defined Key points: Moderately fast acting contact Controls many submersed plants Potential microbial degradation 30

31 2,4-D Specifications Active Ingredient: 2,4-D Herbicide family: phenoxy carboxylic acids Mode of Action: Action like indole acetic acid (synthetic auxins) Key points: Highly selective to control broadleaf plants Systemic, slow-acting Controls submersed, floating, and marginal plants 31

32 Renovate Specifications Active Ingredient: triclopyr Herbicide family: pyridine carboxylic acids Mode of Action: Action like indole acetic acid (synthetic auxins) Key points: Systemic Selective control of submersed and emergent plants 32

33 Which Aquatic Herbicide Should I use? Selecting the right tool starts with the objectives of the water body Drinking, irrigation, fishing, skiing, aesthetics, flood control, all? What plants are present and which should be removed and why? Speed and timing..hurricane approaching or do we have 90 days? Cost? But is cost the main driver in aquatics? 33

34 Killing Plants is Easy but! Protecting and managing a water resource is not! Selecting the right tool is critical. PLANT ID IS THE NUMBER ONE ISSUE IN PRODUCT PERFORMANCE. All herbicides are NOT the same, even within classes Checkpoints of actions.. 34

35 Resistance? Is it Real? Yes! Multiple examples Interesting to note, that generally, as toxicity decreases, resistance potential increases.?!? Why? Single site, multi-site, or unknown Newer products, single site, higher resistance risk! We must manage all products with a long term view! Program Rotation Tank mixes combinations and sequentials! 35

36 Where is the fit for the Right Herbicide? Efficacy Control the target? Water flow? Toxicology No drinking, fishing or swimming restrictions Herbicide Tool Environmental Fate Non-target plants? Water use? 36

37 Aquatic Herbicides are.. Critical Tools for aquatic plant management Environmentally compatible to lake management programs Not all alike; make sure the tool fits the need of the site Herbicides are only better than other herbicides due to the site and circumstances! 37

38 The Two Newest Tools in the Box 38

39 And Tradewind 39