Evaluating Large-scale and Novel Hydrilla Management Projects

Transcription

1 Evaluating Large-scale and Novel Hydrilla Management Projects M.D Netherland, US Army ERDC, Gainesville FL Dean Jones, UF Center for Aquatic and Invasive Plants, Lake Alfred, FL

2 What Is Our Role? Serve as a Technical Resource FWC Invasive Plant Management Section Work Directly with Biologists and Cooperators Work with Private Industry on New Products and Management Strategies Focus on the Development side of R&D Moving research into operations Support observation/anecdote with data

3 Multiple ongoing projects in 2013 (significant cooperation from RB s)_ KCOL Endothall, Bispyribac, Diquat, Penoxsulam, Ludwigia Control, Mapping Efforts Istokpoga Flumioxazin/Diquat, Endothall, Mapping/point intercept Lawne, Lulu, May, Elbert, Hardee Bispyribac and bispyribac + endothall Parker, Ashby, Johns spot endothall + penoxsulam Winterset, Tracy pre and post-treatment PI and mapping Conway Flumioxazin/diquat

4 Challenges to Assessing Largescale treatment outcomes Scale is the key word Outcomes in different areas can vary How long do you assess the site? good control at 8 wks, but poor control at 16 wks Is selectivity a key factor? Our role is to provide objective data

5 Large-scale treatment blocks on Lake Tohopekaliga 1055 acres Dec 12 - Aerial Applications Why so many sampling sites outside of the treatment block? - Functional explanation and concern for non-target impacts

6 Assessment of Treatment Plots at 1 and 2 Months Post-treatment

7 Whole-lake Bispyribac Treatment in March 2012 Mar 21, 2012 Sept 17, 2012

8

9 Objective = Managers and Stakeholders can Visualize Results Example EWM frequency = 36%; most plants were sparse - Dense EWM found mainly between 10 and 15 foot contour - Native vegetation remained dense

10 Advances in Hydroacoustics 2008 to 2010 off the shelf fathometers to log vegetation transect data Analyzed manually 2011 began a cooperative effort with CI Biobase to analyze our plant data (PVI and PAC 2012 recording SAV in large areas and creating vegetation maps at a lake-wide scale 2013 mapped KCOL and Istokpoga

11 Mapped Submersed Vegetation on 70,000+ Acres on the KCOL in Cooperative Effort between UF research and FWC Biologists - Mapping Significant Implications for Pre and Post Management Assessments

12 Value of Hydroacoustic SAV mapping for Large-scale Projects Has changed our approach towards sampling treatment impacts Provides both quantitative and qualitative data Combine with traditional methods (e.g. point intercept) for species information Unbiased method for assessing treatment impacts and rates of recovery

13 How Do We Communicate Technical Info? Technical Exchange Workshops - Orlando Nov day Mtg. (FWC) Netherland, Haller, Jones Meeting planned for Nov 13 1 Day Industry Meetings - Orlando Aug 12 UPI - Endothall Dec 12 Valent - Flumioxazin and Bispyribac Jan 13 SePRO - Penoxsulam, Imazamox, Fluridone Allows us to spend more time on details

14 Assessing Treatment Outcomes Significant time invested in optimizing assessment techniques for large-scale evaluations WHY? If we don t It s Just Our Opinion (and no record) Scaling issues in representing 100 s or 1000 s of acres Need to separate single point in time observations/anecdote from long-term trends Quantitative and non-biased technique Need to effectively compare products or new management techniques

15 What Are We Evaluating? New Products and Product Combinations 5 New registrations since Penoxsulam, 08 Imazamox, 10 Flumioxazin, 11 Bispyribac Can take several years to establish a use pattern Drive to combine products for improved efficacy Endothall + ALS (penoxsulam, bispyribac) Reduced exposure time requirements Flumioxazin + diquat

16 Sustained sampling effort = much improved understanding of Endothall -reduced use rates -selectivity -concentration data -efficacy -timing -liquid vs. granular Within Treatment Plot Outside Treatment Plot C Endothall Conc. µg/l y=1215 *e( * x) r 2 = 0.92 t 1/2 = 10.2 days Days Posttreatment Lake Kissimmee 1200 acre Jan trmt. 16

17 Lake Hatch 500 acre Liquid Aerial Trmt. November Application B 2000 Within Plot Concentrations Outside Plot Concentrations Endothall conc. µg/l y=1694*e ( * x) r 2 = 0.96 t1/2 = 7.6 days Days posttreatment 17

18 May 8, 2012 June 12, 2012 July 18, 2012 Aug 21, % cover 61% PVI 56% cover 29% PVI 81% cover 50% PVI Treated 5/16/ acres at 2 ppm Endothall Warm water spot applications (even larger scale) do not Provide much hold time. Rapid recovery related more to hydrilla growth rates vs. lack of control

19 What Does This All Mean? Hydrilla is Metabolically Active Year Round in FL Susceptible to Endothall Reducing biomass by 90% in Winter Other factors work against recovery (e.g. light, herbivory) Reducing biomass by 90% in Summer Growth rates work against longevity Need to improve understanding of interaction between treatment timing and plant biology

20 KEY Insights Large-scale treatments = extended half-lives = extended control (100% Hydrilla biomass reduction) Shallow and deep water sites Very Difficult to compare efficacy of treatments/products due to influence of sediment type and water depth (clarity) on recovery Multiple observations through time

21 ALS Herbicides + Endothall

22 November treatments of Cypress and Scotty s Cove ALS + Endothall

23 Bispyribac + Endothall Application in Nov 2012 Moderate Exposure Time Nov Dec Jan Feb

24 Shifting sampling & monitoring emphasis to smaller treatments & shoreline strips: Short-term exposures Penoxsulam + endothall on John s Lake Dec 12

25 Lake Huntley ALS alone Long-term Exposures Whole-lake Bispyribac ~25 ppb May 2012 Treatment Pretreatment biomass, transects, and concentration monitoring Integrated w/ planned grass carp stocking

26 Extended Exposures Noted with Several Bispyribac Treatments Concentration of bispyribac-sodium Lake Huntley Half-life > 80 days Concentration (ppb)

27 You don t have to map the whole lake to get good Hydroacoustic data

28 Biomass data from 4 Transects on Lake Huntley g dry wt. / sample Plant 5/15/12 8/1/12 9/18/12 11/19/12 Hydrilla 98 (22) 26 (18) 13 (11) 8 (7) Vallisneria 14 (8) 6 (7) 4 (3) 5 (6) Nitella 7(4) 2 (2) 11 (5) 23 (11)

29 What else are we evaluating? Novel Application Strategies Deep water injection Back to back treatments Extend exposure time to endothall Drip Applications Granulars vs. Liquids

30 Project Spin-Offs * * * * * * * * * * * -Penxosulam + flumioxazin for selective hyacinth and lettuce control - Increased efficiency of boat-based applications - Project initiated on Lake Harris after lunch discussion at Technical Exchange Workshop

31 3.2 Hrs * * * * * * * * * Used Fluorescent Dye - Time of Travel Between Treatment Swaths November and February Applicatio on ~ 500 acres -Patchy hydrilla Established sample points directly behind boat and at 20 ft intervals Between 100 ft application swath widths Can reduce application swaths by 80% (TIME)

32 Application Strategies for Largescale treatments Mode of application is generally not important in terms of treating large blocks aerial vs. airboat vs. granular vs. Litline Get the product out in an efficient manner Can significantly increase boat swath widths without compromising efficacy Cost-effectiveness vs. aerial

33 What About Small Plots? Keep the Application Swaths Tight!! Half-lives in small plots often only HRS

34 Research to Support Operations Evaluating impacts of intermittent endothall exp. Expansion of back to back treatment strategies Challenging assumptions on need for continuous e Evaluating role of turbidity on diquat activity Knowledge on diquat is frozen in a time warp (1970 s) can a quantitative model be developed? Fluridone, microbial degradation,

35 Evaluating Outcomes We need to exercise caution when comparing across products and treatments Rely on a body of information, not single events Longevity of control STRONGLY IMPACTED by environmental factors

36 Can we Link Sediment Mapping with areas of High Growth/Recovery Potential? Hatchineha SAV Cover Hatchineha Sediment Density -Hatchineha has supported greater than 90% hydrilla -What is limiting hydrilla growth in the main body of the lake - Light? - Depth contours do not explain the lack of growth

37 Current Focus -Merge Point Intercept Data with SAV and Sediment Mapping Merge frequency data with spatial information Quantitative data + visualization Statistical analysis (change in frequency) How do sediments impact rates of recovery?

38

39 Fun Facts on Coots - Oldest Known Coot = survived 22 years - Mean daily intake of SAV = 45 g dry wt/coot - Several thousand birds/raft - 30 to 40% of time surface feeding -HOW DO COOTS IMPACT SAV on LARGE LAKES? 39

40 Acknowledgements FWC IPMS Regional Biologists UF Center for Aquatic and Invasive Plants ERDC Aquatic Plant Control Research Prog. Zack Banks and Leif Willey UF IFAS AERF Private Industry Cooperators