Presentation is loading. Please wait.

Presentation is loading. Please wait.

Meddlesome milfoils: Parrotfeather & Eurasian watermilfoil

Similar presentations


Presentation on theme: "Meddlesome milfoils: Parrotfeather & Eurasian watermilfoil"— Presentation transcript:

1 Meddlesome milfoils: Parrotfeather & Eurasian watermilfoil
Biology & ecology of aquatic weeds Meddlesome milfoils: Parrotfeather & Eurasian watermilfoil Vanessa Morgan Center for Lakes and Reservoirs Aquatic Weed Workshop Salem, Oregon April 24, 2014 Aquatic Weed School 10/16/2013

2 Biology & ecology of aquatic weeds
Overview Biology & ecology of aquatic weeds Haloragaceae (water-milfoil family) Eight genera;±100 species Dicot Annual & perennial herbs Generally monoecious & aquatic Myriophyllum spp. 30 species worldwide 14 in North America 3 non-natives + hybrid(s) in PNW Some commonly cultivated Aquatic Weed School 10/16/2013

3 Biology & ecology of aquatic weeds
Overview Biology & ecology of aquatic weeds Identification Impacts Habitats & growth habits Reproduction and dispersal Control options Non-chemical Chemical Aquatic Weed School 10/16/2013

4 Parrot feather (M. aquaticum)
Biology & ecology of aquatic weeds Parrot feather (M. aquaticum) Eurasian watermilfoil (M. spicatum) Heterophyllous Aquatic Weed School 10/16/2013

5 Northern watermilfoil (M. sibiricum)
Biology & ecology of aquatic weeds Whorled watermilfoil (M. verticillatum) Andean watermilfoil (M. quitense) J. Parsons, WA DOE V. Morgan, PSU-CLR V. Morgan, PSU-CLR ©2012 Vernon Smith A. Hipp, U of WI-Stevens Point Aquatic Weed School 10/16/2013

6 Variable-leaf watermilfoil (M. heterophyllum)
Biology & ecology of aquatic weeds Hybrid watermilfoil (M. spicatum × sibiricum) michiganlakeinfo.com L.J. Mehrhoff, U of CT, Bugwood.org ~40% of the lakes surveyed in Michigan's Lower Peninsula were hybrid milfoils L.J. Mehrhoff, U of CT, Bugwood.org © 2014 Donald Cameron V. Morgan, PSU-CLR Aquatic Weed School 10/16/2013

7 Milfoil Character Comparison
submerged leaves Status in PNW # leaflet pairs leaf size leaves/whorl emergent leaves (bracts) winter buds (turions) Northern watermilfoil (Myriophyllum sibiricum) NATIVE <14 (5-14) < 4 cm long 3 to 5 reduced (1-3 mm long); smaller than flowers yes whorled watermilfoil (Myriophyllum verticillatum) < 5 cm long 4 to 5 2-10 mm long; deeply pinnately lobed Andean watermilfoil (Myriophyllum quitense) 5-10 cm long 2 to 5 0.5-1 cm long; partially toothed Parrot feather (M. aquaticum) INVASIVE 10-15 cm long 3 to 6 2-5 cm long; leaflet pairs stiff, waxy, bright green no Eurasian watermilfoil (M. spicatum) > 14 (12-24) 2 - 4 cm long Variable-leaf watermilfoil (M. heterophyllum) 5-12 2-4 cm long 4 to 6 cm long; larger than flowers; serrated/lobed Hybrid watermilfoil (M. spicatum × sibiricum) 8-19 cm long ?

8 ID Verification Multiple samples should be taken prior to any treatment (Moody & Les 2007) Morphological samples: CLR, PSU Genetic verification: Annis Water Resources Institute, Grand Valley State University, MI

9 Biology & ecology of aquatic weeds
Impacts Altered habitats Outcompetes native plants Hybridization with native milfoil species Loss of fish spawning areas Predator-prey relationships Altered food web dynamics Loss of native food sources for waterfowl Reduced phytoplankton Water quality (temperature, oxygen, pH) Irrigation – clogging pumps & intakes Increased mosquito breeding ground Recreational uses (boating, swimming, fishing) – 1% decrease in recreation = $500K loss in recreation) (Eiswerth et al. 2000). Outcompetes native plants = Reduction in plant diversity Loss of native food sources for waterfowl & fish spawning areas Altered predator-prey relationships by fencing out larger fish (preventing consumption of smaller prey fish; end result is skinny, slow growing predators and prey). Shading of water column Aquatic Weed School 10/16/2013

10 Biology & ecology of aquatic weeds
EWM Habitats & Growth Lakes, reservoirs, ponds, rivers, and streams Fresh to brackish water (up to 15 ppt) Depth: (0.5) 1-5 (10) meters pH range: 5.4 to 11 Fine-textured, inorganic sediment Early & rapid spring growth (water temp >15 ͦC) Tops out in water < 5 m Autofragmentation in fall/early winter Overwintering root crowns Extremely adaptable plants; New shoots begin to grow from the overwintering root crowns when water temperature reaches about 60o F in the spring. Growth is rapid and when the plant nears the water’s surface it will branch out creating a canopy. The fast growth and topped out canopy generally occurs before native species peak in growth. Flowering generally occurs in July. Autofragmentation usually occurs after flowering. Plants die back to the roots in the fall. These roots store carbohydrates in order to initiate the rapid growth in the spring. Aquatic Weed School 10/16/2013

11 Reproduction & dispersal
Biology & ecology of aquatic weeds Reproduction & dispersal Fragments Autofragmentation Allofragmentation (boats, swimmers, control efforts) Seed (EWM & Hybrids) Water movement & Waterfowl Aquaria dumps, boats/trailering, bait buckets seed dormancy ~7 yrs Osceola County, Hydrilla Dem. Proj. Rich Miller, PSU-CLR Aquatic Weed School 10/16/2013

12 Non-Chemical Control Options
Biology & ecology of aquatic weeds Method Description Pros Cons Used in Dredging mechanical sediment removal long-term control expense, non-selective shallow small ponds Drawdown dewatering 4-8 wks effective on certain species environ. impacts, Small, man-made lakes/ponds Benthic barriers material covers plants effective, long lasting non-selective, small scale, maintenance near docks, launches, small areas Hand cutting/pulling tools or hand pulling selective labor intensive, expensive localized area, rapid response to new infestations Harvesting mechanical cutting & collection removes biomass expensive, sediment disturbance, short term, non-selective heavy infestations with little/no natives Diver dredging vacuum removal of whole plants selective, longer-term, reduced sediment disturb. expensive, slow localized area, rapid response to new/recent infestations Rotovation aquatic cultivator, tills sediments intermediate results sediment disturbance, spread of fragments Biocontrol insects, fish, etc.. selective, long-term expensive, variable results heavy infestations Aquatic Weed School 10/16/2013

13 Non-Chemical Control Options
Biology & ecology of aquatic weeds Non-Chemical Control Options Method Est. cost Parrotfeather (M. aquaticum) Eurasian watermilfoil (M. spicatum) Dredging variable Drawdown ? Benthic barriers $ /sq. ft. Hand cutting/pulling Harvesting $2,500-3,000/day $500-1,000/acre Diver dredging $1,500-2,000/day (1/4 to 1 acre/day) Rotovation Biocontrol Carp - $5-20/fish Milfoil weevils - $1.20/ind. Parrot feather – high tannin content and woody stems makes it unpalatable to grass carp, EWM – carp will eat it, but it is not a favored food. 7 – 15 carp per surface acre; loss of all other macrophytes since they will preferentially feed on almost everything else. Weevils - weevils eat and burrow in the Eurasian Milfoil meristem, causing the plants to weaken, loose buoyancy, and eventually sink. Aquatic Weed School 10/16/2013

14 EWM Chemical Control Options
Biology & ecology of aquatic weeds Whole lake/pond treatments Goal: eradication of heavy infestations Systemics (fluridone, 2,4-D, triclopyr) offer excellent control Partial or spot treatments Goal: suppress EWM growth, allow native plant recovery Contact herbicides (endothall, diquat) offer good control Aquatic Weed School 10/16/2013

15 Prerequisites for Efficacy
Adequate concentration & contact time Water exchange & plant biovolume Proper placement (proximity for uptake) Optimal season and phenological stage Appropriate water quality Turbidity interferes with diquat

16 Biology & ecology of aquatic weeds
Application methods Clean Lakes, Inc. Liquids Boat-mounted hose for sub-surface injections Foliar sprays Pelletized & granular formulations (slow & quick release) Boat mounted hopper/spreader to ensure even application * boat speed; rate of delivery from the spreader; swath width Vassios et al. 2014 (Miles per hour X spreader width X Pounds per Acre) / 495 = Pounds per Minute In areas where dilution could be an issue, use of systemic granular products may lead to improved root uptake University of Florida, IFAS Extention Aquatic Weed School 10/16/2013

17 Biology & ecology of aquatic weeds
EWM Control cont… Fluridone (Sonar, Avast!) Systemic, slow acting (45-90 days) Selective at low doses, non-selective at higher rates 8-10 ppb maintained for 10 wks (16-75 ppm recommended label rates) FasTEST (SePRO) determines concentration & any needed bump treatments Higher rates for dense weed mats Whole lake, eradication treatments – liquid liquid formulation by sub-surface injection Granular formulations applied with blowers to ensure even application 8-10 ppb allows some selectivity, label rates suggest 16-75 Reference to specific tradenames is not intended as an endorsement Aquatic Weed School 10/16/2013

18 Biology & ecology of aquatic weeds
EWM Control cont… Biology & ecology of aquatic weeds 2,4-D Systemic, fast acting; selective treats dicots Formulations Granular – butoxy-ethyl-ester Navigate and Aqua-Kleen; toxic to fish/aquatic inverts lbs/acre Liquid - dimethylamine salt DMA*4IVM; 4 ppm (2.84 gal/acre foot) Aquatic Weed School 10/16/2013

19 Biology & ecology of aquatic weeds
EWM Control cont… Biology & ecology of aquatic weeds Triclopyr (Renovate 3 – liquid; Renovate OTF – granular) Systemic, fast acting Selective treats dicots; native pondweed species and coontail, rushes and cattails unaffected Liquid to 2.5 ppm a.e.; sinking agent > 6’ Granular – 0.5 to 2.5 ppm a.e. Aquatic Weed School 10/16/2013

20 Chemical - recent developments
Biology & ecology of aquatic weeds Flumioxazin (Clipper) Non-selective, liquid contact herbicide ppb submersed Quick kill – potential dissolved oxygen problems Bispyribac-sodium (Tradewind) Non-selective; slow acting, wetable powder 20-45 ppb, maintained for days Use patterns still developing Aquatic Weed School 10/16/2013

21 Chemical - recent developments
Biology & ecology of aquatic weeds Chemical - recent developments (EWM) Long-term exposure, low rates of 2,4-D or triclopyr may provide control for EWM & hybrids (Glomski et al. 2010, Poovey et al. 2007) Individual hybrid population responses Impacts to native plants (hybrid milfoil) (Glomski et al. 2010) Aquatic Weed School 10/16/2013

22 EWM Chemical Control Options
Biology & ecology of aquatic weeds Whole lake/pond treatments Goal: eradication of heavy infestations Systemics (fluridone, 2,4-D, triclopyr) offer excellent control Partial or spot treatments Goal: suppress EWM growth, allow native plant recovery Contact herbicides (endothall, diquat) offer good control Aquatic Weed School 10/16/2013

23 Biology & ecology of aquatic weeds
EWM Chemical cont… Biology & ecology of aquatic weeds Contact herbicides Diquat dibromide (Reward, Weedtrine) nonselective, liquid contact herbicide Not for use in turbid waters gal/surface acre Endothall (dipotassium salt-Aquathol, Cascade) nonselective, liquid or granular spot treatments ppm Control is temporary – root crowns not killed Quick kill – potential dissolved oxygen problems Aquatic Weed School 10/16/2013

24 Parrotfeather Habitats & Growth Habits
Biology & ecology of aquatic weeds Parrotfeather Habitats & Growth Habits Lakes, ponds, canals, and other slow moving waters High nutrient inputs Depth: wet banks to 2 m pH range: 6.8 to 8 Temperature:16 to 23 ͦC Emergent growth ~ 1’ above water; lateral, branching stolons Flowers form in spring, no seed production Submersed leaves senesce in early summer Wersal and Madsen 2011 Extremely adaptable plant Biomass much greater in shallow waters – Wersal and Madson’s mesocosm study (2011) showed 96% greater total biomass for plants grown at 0 cm vs. 1.4 m Nuisance growth really dependent upon parrotfeather emerging from the water Aquatic Weed School 10/16/2013

25 Parrotfeather Control
Biology & ecology of aquatic weeds Parrotfeather Control Robust rhizomes Waxy cuticle on emergent leaves, requires wetting agent Use of contact herbicides (diquat & endothall) of limited use No single treatment effective Imazapyr & triclopyr most promising for long-term control Normally a variety of light levels, and a number of micro-habitats, but this weed creates one set of conditions Higher rates for dense weed mats Whole lake, eradication treatments – liquid 8-10 ppb allows some selectivity, label rates suggest 16-75 Aquatic Weed School 10/16/2013

26 Parrot feather – foliar applications
Biology & ecology of aquatic weeds Parrot feather – foliar applications Imazapyr (Habitat, Arsenal) Inhibits plant-specific enzyme (ALS-inhibitor) Slow-acting, moderate residual soil activity 2-4 pints/acre to actively growing emergent foliage Triclopyr (Renovate 3) 1.0 to 2.5 ppm a.e/acre Good to fair canopy knockdown, rapid regrowth Imazamox (Clearcast) Slow-acting, impacts days Fair canopy suppression 1-2 pints/acre Broad spectrum systemics Wersal & Madsen 2007 Aquatic Weed School 10/16/2013

27 Parrot feather – subsurface
Biology & ecology of aquatic weeds Triclopyr (Renovate Max G, Navitrol DPF) 1.0 to 2.5 ppm a.e./acre repeat treatments needed Endothall (Aquathol K, Aquathol Super K, Cascade) Whole pond/large area: ppm ( gal/ac.ft. liquid; lbs/ac.ft granular) Spot treatments: ppm ( gal/ac.ft. liquid; lbs/ac.ft granular) Aquatic Weed School 10/16/2013

28 Considerations Proper identification & verification
Repeat treatments & continued monitoring Timing – target plants actively growing and, when possible, when non-target plants are dormant Consider IPM approach Upstream/nearby propagule source Secondary invasion (replacing EWM with curly pondweed?) Chemical treatments: Partial treatments – 1/3 to 1/2 of total area Use restrictions (drinking, livestock, irrigation, swimming) “The label is the law”

29 Resources Biology and Control of Aquatic Plants: A Best Management Practices Handbook (http://www.aquatics.org/aerf_handbook.pdf) PNW Weed Management Handbook (http://pnwhandbooks.org/weed/) WA Dept. of Ecology, Aquatic Plant Management (http://www.ecy.wa.gov/programs/wq/plants/plantmgmt.html) Information Center Online (PICOL) Databases (http://picol.cahe.wsu.edu/LabelTolerance.html)

30 Biology & ecology of aquatic weeds
References Biology & ecology of aquatic weeds Eiswerth, M. E., Donaldson, S. G., & Johnson, W. S. (2000). Potential Environmental Impacts and Economic Damages of Eurasian Watermilfoil (Myriophyllum spicatum) in Western Nevada and Northeastern California 1.Weed Technology, 14(3), Glomski, L. M., & Netherland, M. D. (2010). Response of Eurasian and hybrid watermilfoil to low use rates and extended exposures of 2, 4-D and Triclopyr.Journal of Aquatic Plant Management (JAPM), 48, 12. Hofstra, D. E., Champion, P. D., & Dugdale, T. M. (2006). Herbicide trials for the control of parrotsfeather. Journal of Aquatic Plant Management, 44(1), Moody, M. L., & Les, D. H. (2007). Geographic distribution and genotypic composition of invasive hybrid watermilfoil (Myriophyllum spicatum× M. sibiricum) populations in North America. Biological invasions, 9(5), Patten, K. (2007). Parrotfeather milfoil (Myriophyllum aquaticum) – Assessment of management alternatives. Final Progress report to WA Dept. of Ecology. Poovey, A. G., Slade, J. G., & Netherland, M. D. (2007). Susceptibility of Eurasian watermilfoil (Myriophyllum spicatum) and a milfoil hybrid (M. spicatum x M. sibiricum) to triclopyr and 2, 4-D amine. J. Aquat. Plant Manage, 45, Vassios, J. D., Nissen, S. J., Koschnick, T. J., & Heilman, M. A. (2014). Triclopyr Absorption and Translocation by Eurasian Watermilfoil (Myriophyllum spicatum) Following Liquid and Granular Applications. Weed Science, 62(1), Wersal, R. M., & Madsen, J. D. (2007). Comparison of imazapyr and imazamox for control of parrotfeather (Myriophyllum aquaticum (Vell.) Verdc.). J. Aquat. Plant Manage, 45, Aquatic Weed School 10/16/2013


Download ppt "Meddlesome milfoils: Parrotfeather & Eurasian watermilfoil"

Similar presentations


Ads by Google