2019 Conference Info/Registration

Texas Aquatic Plant Management Society
Annual Conference
November 18 – 20, 2019


The Stella Hotel

Bryan, Texas

Photo of The Stella Hotel

Education, Networking, Exhibitors, and TDA CEUs

Who should attend: All TAPMS members and others who are interested in aquatic plant management, biology or ecology, or who are involved in the protection, management and restoration of water and wetland resources, are invited to attend. Whether you work in the public or private sector, as an aquatic weed management professional, water resource manager, researcher, or regulatory official, the TAPMS annual conference delivers up to date information.

Topics covered: Aquatic plant management tools and techniques, recent technological advances, new research relevant to your work, environmental laws and regulations, public outreach initiatives, business development, and TAPMS business. All TDA certified aquatic pesticide applicators can receive up to 5 CEU credits.


Abstract submission for the 2019 TAPMS Annual Conference is now open. The 2019 Draft agenda is located at the bottom of this page. For more information on past presentations, including abstracts please contact President-elect and Program Chair, Kristy Kollaus (kkollaus@edwardsaquifer.org) with any questions.

Submit an abstract
Download the call for presentations

Information for Student Presenters

Student presenters at the 2019 TAPMS Annual Conference have the opportunity to share their research with a broad audience of professionals. View and download student flyer. Best student presenter will receive an award and prize. The TAPMS also offers a $1,500 scholarship to a deserving college student who attends the 2019 conference and submits an application–presentation is not required but recommended. Registration for student presenters is free and student attendees will receive free TAPMS student membership. The Aquatic Ecosystem Restoration Foundation will provide full reimbursal (no advance payments) of 2019 travel costs for the first ten student applicants; partial reimbursal may be available for later applicants. For more information on student scholarships, presentation awards and judging criteria, and travel reimbursal see below:

  2019 TAPMS Student Scholarship Information & Application

 Student Oral & Poster Presentation Awards – Information & Criteria

  Student Presenter Travel Reimbursal Information & Request Form

Conference Registration

Information for 2019 registration coming soon. Individual 2019 TAPMS memberships will be FREE with paid conference registration.

Room Reservations

TAPMS has reserved guest room at a discounted group block rate of $115.00 for the dates of the conference.

Photo of Stella Hotel Pool Image

Location details:

The Stella Hotel

BRYAN, TX 77807
(979) 421-4000

Guest Room Booking link for the attendees to make their reservations:
TAPMS 2019 Conference
Attendees can also call the hotel directly at 979-421-4000 and ask to book a room in the TAPMS 2019 Conference” block or they can go to www.thestellahotel.com and use the Group Code: TAPMS1119. However, the booking link is the easiest and most reliable booking method.

Sponsors and Exhibitors

Corporate memberships are a way to represent your business at TAPMS and be recognized as a conference sponsor. Corporate membership dues are used to support non-event-specific conference services that are vital to the success of the event such as facility deposits, programs, placards, advertisement, sound system rentals, plaques, office supplies, and all the little things that make the conference happen. Sponsorships are available at levels from Bronze to Diamond, for conference events, and for student support. Sponsors will be recognized at the conference and in the program.

Exhibitor Booth
High visibility booth location
Approximately 3’ x 15’’ table and up to two chairs
Electric power available upon request
Exhibitors must provide their own self-supporting or table-mounted display boards



* Indicates student presentation.

CEU indicates attendance credit of 1.0 CEU except in session 6 each is 1/3 CEU (pending TDA confirmation)


Monday – November 18, 2019

12:00 PM – 3:00 PM Pre-conference board meeting/work session (Board Members; Orion)

1:00 PM – 7:00 PM 6th Annual TAPMS Golf Tournament (Phillips Event Center)

Sponsored by: WinField United (Diamond Sponsor)

4:00 PM – 6:00 PM Conference early check-in and onsite registration (LUNA)

4:00 PM – 6:00 PM Exhibitor set up (Prefunction B)

6:30 PM – 8:30 PM President’s reception (The Backyard)

Sponsored by: WinField United (Diamond Sponsor),

Outdoor Water Solutions (Platinum Sponsor)


Tuesday – November 19, 2019

7:00 AM – 8:00 AM Conference check-in and onsite registration (LUNA)

7:30 AM – 8:30 AM Continental breakfast (Prefunction B)

Opening Remarks

8:00 AM – 8:10 AM Welcome & announcements 

(Chris Smith; TAPMS President)

8:10 AM – 8:20 AM Welcome from Platinum Sponsor, Winfield United, and update on research and operations related to aquatic plant management. 

(Chris Smith; Winfield United)

Session 1: Updates and Overviews (Moderator: Chris Smith)

8:20 AM – 8:30 AM Aquatic Plant Management Society Update 

(Mark Heilman; APMS President

8:30 AM – 9:20 AM CEU Overview and updates on state & federal laws and regulations

(Carlton Layne; Aquatic Ecosystem Restoration Foundation)

9:20 AM – 10:10 AM CEU Statewide integrated pest management of aquatic and riparian invasive species

(John Findeisen and Monica McGarrity; Texas Parks & Wildlife Department)

10:10 AM – 10:30 AM Morning Refreshment Break, Raffle; Applicators complete 2 CEU roster for Session 1 

Session 2: Aquatic Plant Ecology & Conservation (Moderator: Melani Howard)

10:30 AM – 10:50 AM A thirty-year assessment of the endangered aquatic macrophyte, Zizania texana, endemic to the upper reach of the San Marcos River

(Jeffrey Hutchinson, Ph.D.; University of Texas – San Antonio)

10:50 AM – 11:10 AM Native Texas aquatic plants: An overview and case studies 

(Casey Williams; BIO-WEST, Inc)


Tuesday – November 19, 2019

Session 2: Aquatic Plant Ecology & Conservation (Continued)

11:10 AM – 11:30 AM *Establishment of macrophytes in Honeycut Springs, C.L. Browning Ranch, Johnson City, Texas 

(Landon Camp, Jeffrey Hutchinson; University of Texas-San Anotnio and Scott Gardner; C.L. Browning Ranch)

11:30 AM – 11:50 AM Conservation of endangered Texas wildrice and its habitat in the San Marcos River

(Christopher Hathcock, Ph.D.; U.S. Fish and Wildlife Service)

11:50 AM – 12:10 PM *Mitigation of invasive aquatic species to preserve native submerged aquatic vegetation in the San Marcos River, Texas. 

(Francesca Filippone, Christopher Riggins, and Collin Garoutte; Texas State University – The Meadows Center for Water and the Environment)

12:10 PM – 1:10 PM Luncheon (Celeste B&C)

Sponsored by: WinField United (Diamond Sponsor), Applied Biochemists (Platinum

Sponsor), Syngenta (Gold Sponsor), Outdoor Water Solutions (Gold Sponsor), UPI (Gold Sponsor)

Session 3: Ecology and Management of Invasive Species (Moderator: Jason Chapman)

1:10 PM – 2:00 PM CEU Introduction pathways for invasive aquatic plants 

(Lyn Gettys, Ph.D; University of Florida)

2:00 PM – 2:20 PM *Nymphoides in Florida

(Ian Markovich, Kyle Thayer, Joseph Sigmon, Mohsen Tootoonchi, and Lyn Gettys, Ph.D.; University of Florida)

2:20 PM – 2:40 PM An inconspicuous invasive Hygrophila polysperma: Its ecology and identification 

(Casey Williams, BIO-WEST, Inc)

2:40 PM – 3:00 PM *Efficacy of aquatic herbicides and combinations on redroot floater and Azolla in mesocosms 

(Joseph Sigmon, University of Florida

3:00 PM – 3:20 PM *Procellacor efficacy on submersed plants at varying contact exposure times            

(Kyle Thayer, Ian Markovich, Joseph Sigmon, Mohsen Tootoonchi, and Lyn Gettys, Ph.D.; University of Florida) 

3:20 PM – 3:50 PM Afternoon Refreshment Break; Raffle; Applicators complete 1 CEU roster for Session 3 


Tuesday – November 19, 2019

Session 4: Management of Nutrients in Water Bodies (Moderator: Brad Vollmar)

3:50 PM – 4:10 PM Understanding and managing the influence of nutrients in water resources

(Clint Formby; Sepro Corporation)

4:10 PM – 4:30 PM *Tapegrass from different regions tolerates different amounts of salt

(Mohsen Tootoonchi, Lyn Gettys, Ph.D., Kyle Thayer, Ian Markovich, and Joseph Sigmon; University of Florida)

4:30 PM – 4:50 PM Can invasion be reversed by removing the main driver or has a regime shift occurred? A test case using a simulated wetland ecosystem 

(Jason Martina, Ph.D.; Texas State University)

4:50 PM – 5:00 PM Closing remarks for the day 

(Chris Smith, TAPMS President)

Tuesday Post-Session Events

5:15 PM – 6:00 PM Women of Aquatics Meeting (TBD)

6:30 PM – 8:00 PM Banquet Dinner & Awards (Celeste B&C)

Sponsored by: WinField United (Diamond Sponsor)

8:00 PM – 9:00 PM Closing Cocktail Hour (Celeste B&C)

Wednesday- November 20, 2019

7:00 AM – 8:00 AM Conference check-in and onsite registration (LUNA)

7:30 AM – 8:30 AM Continental breakfast (Prefunction B)

Opening Remarks

8:00 AM – 8:05 AM Welcome & announcements 

(Chris Smith; TAPMS President)

8:05 AM – 8:10 AM Welcome from Diamond Sponsor, Outdoor Water Solutions, and update on research and operations related to aquatic plant management.

(John Redd; Outdoor Water Solutions President)

Session 5: Drift Technique and Chemical Use for Invasive Species Control (Moderator: Kristy Kollaus)

8:10 AM – 9:00 AM CEU Drift Minimization: Maximizing your chemical investment: When bad things happen to good droplets

(Chris Smith; Winfield United)

9:00 AM – 9:20 AM Operational experiences with ProcellaCOR for key Texas aquatic invasive plants

(Mark Heilman; SePro Corporation)

9:20 AM – 9:40 AM Use of granular copper EDA (Harpoon) for Hydrilla control in Texas                                                         (Paul Westcott, Kelly Duffie, Dave Bass, Bill Ratajczyk, and Ryan Wersal; Applied 


Wednesday- November 20, 2019

Session 5: Drift Technique and Chemical Use for Invasive Species Control (Continued)

9:40 AM – 10:00 AM More bang for your buck: Using less copper to control harmful algal blooms                                                         (Patrick Simmsgeiger; Southwest Aquatic Services)

10:00 AM – 10:20 AM Morning Refreshment Break, Raffle; Applicators complete 1 CEU roster for Session 5

Session 6: Texas Invasive Management Strategies (Moderator: TBD)

10:20 AM – 10:40 AM CEU Managing nuisance vegetation in the San Marcos River for endangered species

(Bryce Cuda; Cuda Conservation)

10:40 AM – 11:00 AM CEU Cyrtobagous salviniae (Salvinia weevil) and its role in Salvinia control in Texas 

(Thomas Decker; Texas Parks and Wildlife Department)

11:00 AM – 11:20 AM CEU Aeration: A key tool in aquatic system restoration and management

(Patrick Goodwin; Vertex Water Features)

11:20 AM – 11:40 AM “Protect the lakes you love”: TPWD’s aquatic invasive public awareness campaign

(Carly Montez; Texas Parks and Wildlife Department)

11:40 AM – 11:50 AM Conference Final Address and looking forward to the 2020 joint AMPS/TAPMS meeting                                                                                          (Chris Smith, TAPMS president)

11:50 AM – 12:20 PM Applicators receive CEU certificates 

Post-Conference Events 

1:00 PM – 2:30 PM Post-Conference Board Meeting (Orion)


Abstracts are listed alphabetically by presenting / first author last name. 

* Indicates student presenter

CEU indicates attendance credit of 1.0 CEU except in session 6 each is 1/3 CEU (pending TDA confirmation)

*Establishment of macrophytes in Honeycut Springs, C.L. Browning Ranch, Johnson City, Texas

Camp, Landon1, Jeffrey Hutchinson1, and Scott Gardner2

1University of Texas at San Antonio, 2C.L. Browning Ranch

Honeycut Springs is a spring-fed river at C.L. Browning Ranch in Johnson City, Texas. A small concrete dam 250 m from the spring head resulted in siltation > 1 m deep and the area became dominated by torpedograss (Panicum repens), an invasive aquatic grass. The largest area of torpedograss (167 m3) was removed by dredging during June 2018. Restoration of native riparian and aquatic plants was initiated in September and November 2018. Limited planting of riparian plants included Emory’s sedge (n = 41), Texas rush (n = 25), tussock spikerush (n = 22), knotgrass (n = 15), and American water willow (n = 15). Aquatic plants were planted in two separate sites and included creeping primrose willow (n = 50), Illinois pondweed (n = 50), water hyssop (n = 50), water pennywort (n = 25), water stargrass (n = 20), and delta arrowhead (n = 17). At 9 months post-planting, survival of riparian plants ranged between 7% (knotgrass) to 24% (Emory’s sedge). Aquatic plant survival ranged from 8% (delta arrowhead) to 56% (Illinois pondweed). Water stargrass was the only plant that did that survive following initial plantings. Emory’s sedge increased from 0.01 m2 (Nov 2018) to 6.5 m2 (July 2019) and tussock spikerush and Texas sedge also increased, but at a lower rate following the initial planting. Illinois pondweed increased from 0.08 m2 (Nov 2018) to 21.8 m2 (July 2019). Creeping primrose willow and water pennywort also increased in area coverage following initial plantings. Aquatic species richness increased from 4 species (July 2018) to 13 species (July 2019) but diversity and evenness indices remained low due to algae (Mouogeotia spp.) coverage. Based on these results, additional plantings will occur in 2018-2020.

Managing nuisance vegetation in the San Marcos River for endangered species

Cuda, Bryce

Cuda Conservation

My small business, Cuda Conservation, has worked Edwards Aquifer Habitat Conservation Plan contracts for about two years on the San Marcos River.  The bulk of my work as Cuda Conservation in San Marcos focuses on enhancing the health of native species in the river and riparian areas through landscape management.  One of the problems Cuda Conservation addresses in the San Marcos River, is the accumulation of floating vegetation. The floating vegetation catches and builds up on native aquatic plants that are important to the ecosystem.  Aquatic plants fragment and float downstream as a result of river recreation, “mowing” in Spring Lake (headwaters) and natural fragmentation. The fragments form mats that increase in volume quickly and shade or even displace established native aquatic plants.  In the riparian areas along the San Marcos River and its tributary creeks, various non-native plant species grow and create a non-native habitat usually dominated by one species. It can be difficult for native species to compete with some of the non-native species exhibiting allelopathic effects.  Cuda Conservation removes and treats these species and uses the removed material to make berms that assist in increasing infiltration and prevent trash from going to the river during a storm.

CEU Cyrtobagous salviniae (salvinia weevil) and its role in salvinia control in Texas 

Decker, Thomas 

Texas Parks & Wildlife Department

The salvinia weevil (Cyrtobagous salviniae) is a small weevil native to the same regions in South America as giant salvinia and has been used as a biological control agent for decades. Herbicide application is still currently the most efficient means of controlling giant salvinia in Texas, but Texas Parks and Wildlife Department uses salvinia weevils as an important part of an integrated pest management strategy on several water bodies where herbicide applications are not feasible, or would be detrimental to aquatic habitat on a large scale. TPWD rears weevils at several of its own facilities, collaborates with a nonprofit organization that rears weevils, and harvests weevils from established populations and releases them into other populations of giant salvinia.

*Mitigation of invasive aquatic species to preserve native submerged aquatic vegetation in the San Marcos River, Texas

Filippone, Francesca, Christopher Riggins, and Collin Garoutte

Texas State University – The Meadows Center for Water and the Environment

The conservation of natural aquatic ecosystems is dependent on the composition and densities of native submerged aquatic vegetation (SAV) populations to maintain the biogeochemical processes and tropic chains that organisms are reliant on. Issues arise when non-native macrophytes establish within aquatic systems and begin to disrupt the native community by altering water chemistry, allowing for sediment deposition, and through the displacement of native species. Mitigation strategies of aquatic invasive species include mechanical, physical, biological, and chemical means. Removal process limitations are placed upon the Edwards Aquifer Habitat Conservation Plan (EAHCP) due to the endemic ecology of the San Marcos River. The EAHCP implements strategies to manage aquatic invasive vegetation as well as floating vegetation mats to preserve the environment of the native, endangered species Zizania texana that inhabits the upper portion of this waterway. Removal efforts are performed in the least intrusive manner through hand-removal methods in conjunction with a top-down strategy focused on natural expansion of native species. Since the approval by the Fish and Wildlife service in February 2013, the EAHCP has engaged in removal efforts towards reducing the aerial coverage of Hydrilla verticillata and Hygrophila polysperma in order to promote the growth of native SAVs in the San Marcos River. An adaptive management process was adopted as a result of the analysis of mapped vegetation expansion and data collection of previous removal techniques.

CEU Statewide integrated pest management of aquatic and riparian invasive species

Findeisen, John and Monica McGarrity

Texas Parks & Wildlife Department

This presentation will provide an update on Texas Parks and Wildlife Department’s aquatic vegetation and invasive species management efforts in Fiscal Year 2018 (Sept. 2017 – Aug. 2018), with a focus on implementation of an Integrated Pest Management (IPM) strategy. Texas’ IPM strategy employs a combination of prevention, herbicide treatments, biological control efforts, and outreach for not only prevention but also to promote environmental stewardship (e.g., enhancing creek health) and involvement in citizen science monitoring efforts. Early Detection and Rapid Response (EDRR) capacity is vital to efforts to monitor for new infestations of the most problematic species such as giant salvinia (Salvinia molesta) and zebra mussels (Dreissena polymorpha) and mount a rapid response when feasible. 

Management efforts continue to focus on floating, aquatic invasive plants and riparian invasive plants that 

crowd or shade out native plants, degrade habitat for fish and wildlife, and inhibit boater access. Management of aquatic and riparian invasive species using an IPM approach plays a key 

role in conserving Species of Greatest Conservation Need (SGCN) and providing hunting, fishing and outdoor recreation opportunities for the use and enjoyment of present and future generations.

Understanding and Managing the Influence of Nutrients in Water Resources

Formby, Clint

Sepro Corporation

Algal blooms are increasingly impacting water resources throughout the United States and globally. A preventative approach to addressing these blooms is gaining social and regulatory favor. Managing nutrient sources, concentrations and ratios is can be an effective approach to help offset or direct bloom formation. Specifically mitigating in situ water and sediment phosphorus can positively shift nutrient ratios and govern algal types/densities. In this presentation, information regarding nutrients and how they align with algal ecology and consequent growth patterns will be provided. Additionally, results of nutrient mitigation programs and case studies will be provided to apply these concepts. Strategically incorporating preventative technologies focused on nutrient mitigation will be needed to offset the growing threat of algal blooms.\

CEU Introduction pathways for invasive aquatic plants

Gettys, Lyn A, Ph.D.

University of Florida

Introduction pathways for exotic aquatic species are many and diverse, and this talk will describe the events that led to the introduction of several historically problematic aquatic species, including waterhyacinth (Eichhornia crassipes) and hydrilla (Hydrilla verticillata). Also on the slate will be a discussion of the likely introduction pathways responsible for a number of new invaders, including feathered mosquitofern (Azolla pinnata), giant salvinia or kariba-weed (Salvinia molesta), rotala (Rotala rotundifolia), redroot floater (Phyllanthus fluitans), and crested floatingheart (Nymphoides cristata). Attendees will learn that the most effective strategy to reduce the introduction and spread of invasive aquatic species is through diligent monitoring and increased public awareness of the environmental damage caused by non-native invasive species.

Aeration: A key tool in aquatic system restoration and management 

Goodwin, Patrick

Aquatic Systems, Vertex Water Features

Urban runoff can consistently deliver water with high nutrient concentrations, sediments, metals and other pollutants to lake systems.  This leads to sediment build up, eutrophication and associated changes in flora and fauna, including the proliferation of Cyanobacteria blooms and the growth of aggressive invasive species that thrive under high nutrient conditions.  Lake managers must therefore employ various methods to reduce the effects of waste water on the overall state of the urban lakes. This presentation will review the benefits of aeration as a tool in managing lakes and ponds. Aeration improves a lake’s ability to adapt to and process nutrient inputs by enhancing the natural processes that facilitate nutrient uptake and storage, and sediment breakdown.  Aeration therefore has the potential to increase water circulation, oxygen availability and oxidation reduction potentials, while reducing carbon dioxide, phosphorus, nitrogen ammonia, biological oxygen demand and hydrogen sulfide (odor). The mechanisms for which aeration can improve a lakes health will be explained and a brief consideration will also be given to the designing and sizing of lake aeration.  

Conservation of endangered Texas wild rice and its habitat in the San Marcos River

Hathcock, Christopher R. 

U.S. Fish and Wildlife Service

Zizania texana is a federally endangered aquatic grass restricted to the first 4.3 km of the spring-fed, thermally constant San Marcos River in San Marcos, TX, USA. Annual surveys led by the Texas Parks and Wildlife Department since 1989 have shown a consistent increase in areal coverage of the population from just over 1,000 m2 in 1989 to over 4,500 m2/year from 2010 to 2013, and to over 8,400 m2/year from 2014 to 2019. Recent increases are likely due, in large part, to successful, large-scale reintroduction and habitat improvements through the Habitat Conservation Plan (HCP) of the Edwards Aquifer Recovery Implementation Program (EARIP) beginning in 2012. Since 2013, over 55,000 Texas wild rice plants, grown from both seeds and tillers, were planted in the San Marcos River over an area of approximately 4,000 m2. These plantings were concurrent with removal of invasive exotic plant species and additional plantings of other native species. Improved propagation and refugium management techniques are on-going at the San Marcos Aquatic Resources Center of the U.S. Fish and Wildlife Service. Past and current status of the Texas wild rice population, and recent management and research will be discussed.

Operational experiences with ProcellaCOR for key Texas aquatic invasive plants

Heilman, Mark

SePro Corporation

After its spring 2018 federal registration, ProcellaCOR Aquatic Herbicide (a.i., florpyrauxifen-benzyl) has been utilized successfully for control of major aquatic weeds challenging Texas waterways. Hydrilla, floating hearts, water hyacinth, and several other key target exotic species have been selectively managed with low-rate applications as predicted from earlier mesocosm and field trials. Findings of operational demonstrations and quantified field efficacy for 2018-2019 ProcellaCOR projects relevant to Texas managers will be discussed to help refine future management efforts.

A thirty-year assessment of the endangered aquatic macrophyte, Zizania texana, endemic to the upper reach of a single river in Central Texas

Hutchinson, Jeffrey, Ph.D. 

University of Texas – San Antonio

Texas wild rice is an endemic, federally endangered aquatic macrophyte known from the upper San Marcos River in central Texas. Annual surveys of Texas wild rice coverage have occurred for 30 years from 1989 to 2018 documenting the known coverage within its limited range. Texas wild rice exhibited a progressive increase in coverage from 1989 to 2018, but coverage increased significantly (P < 0.001) following 2013 when plantings began. Following planting of Texas wild rice, we observed a strong positive relationship (R2 = 0.84) with increases in coverage to the number of Texas wild rice planted per year. The most significant (P < 0.05) increases in Texas wild rice coverage occurred in six of the seven upper sections of the river, while significant (P < 0.05) decreases occurred in five of the seven lower sections of the river. There was no correlation between Texas wild rice coverage and mean (r = 0.13), minimum (r = 0.18), and maximum (r = -0.08) discharge rates. The maximum discharge recorded during the survey was 175 m3 s-1 in 1998 which resulted in a 15.6 % decrease in coverage during the 1999 survey, but Texas wild rice coverage increased during 2000. Texas wild rice has survived for an unknown period of time in the upper San Marcos River and is known from no other location. This endangered macrophyte exhibits resilience, and in particular resistance to high discharge events due to its fast growth rates, reproductive plasticity, high root to shoot ratios, and a perennial life cycle that contribute to its fast recovery following scouring. The greatest threat to the only known population of Texas wild rice is decreased spring flows due to increased water extraction.

CEU Overview and Updates on State & Federal Laws and Regulations 

Layne, Carlton

Aquatic Ecosystem Restoration Foundation

This presentation will provide valuable information on laws and regulations governing our industry, including pesticide use/misuse, the safe use of pesticides, Federal Government standards, NPDES/WOTUS updates, and label changes and warnings. 

* Nymphoides in Flordia

Markovich, Ian J., Kyle L. Thayer, Joseph Sigmon, Mohsen Tootoonchi, and Lyn A. Gettys 

University of Florida

Nymphoides is a remarkably diverse genus with species that have a broad phylogenetic distribution and morphological variation. Florida has seen an increase in the number of Nymphoides sp. in the state and therefore the risk of potential hybridization between species could be on the rise as well. The scope of this presentation is to describe the newly vouchered species in Florida and to discuss possible control methods for some of the invasive species of this genus.

Can invasion be reversed by removing the main driver or has a regime shift occurred? A test case using a simulated wetland ecosystem

Martina, Jason P., Ph.D.

Texas State University

Invasions by Phragmites australis and Typha spp. in wetlands are strongly influenced by nitrogen (N) loading and are managed with varying degrees of long-term success, in part due to persistent eutrophication. However, even if N loading decreased, invasion might persist because a regime shift, reinforced by higher intrasystem (plant-sediment) N cycling, maintains invader dominance. We used Mondrian, a wetland community-ecosystem model, to explore Phragmites and Typha invasion success, failure, and persistence in a 3-species native community across a range of N loading scenarios. These included constant or decreasing N loading where the system starts in a eutrophied state and ends in a low N loading state across a 50-year time period, representing a lowering of N inflow from human activity. In the constant N loading scenarios, an invasion threshold was observed between 8 and 12 g N m-2 yr-1, in which the proportion of invaders went from less than 20% to greater than 80%. Under flooded conditions, both invaders continued to dominate the community even after a major N reduction, i.e., a regime shift occurred. Associated with this persisting invasion, the wetland maintained high productivity, N mineralization, and plant N uptake. However, this regime shift was not as strong with lower water levels, where reducing N loading allowed N cycling to return to nearly pre-invasion levels, partially reducing invader dominance. These results suggest that in flooded, historically high N loading wetlands, in the absence of further intervention, invasions can persist even after the main driver, high N loading, is removed.

“Protect the lakes you love.”: TPWD’s aquatic invasive species public awareness campaign

Montez, Carly

Texas Parks & Wildlife Department

The Texas Parks and Wildlife Department (TPWD) believes that a key part of effective aquatic invasive species management is outreach and prevention. Beginning in 2010, TPWD, supported by a coalition of partners, has implemented a public awareness campaign aimed at slowing or stopping the spread of harmful invasive species such as giant salvinia and zebra mussels by motivating boaters to clean, drain and dry their boat or vessel, trailer, and gear before traveling from lake to lake. The most recent campaign messaging – “Protect the lakes you love.” – was informed by consumer research, including focus groups and online surveys, of registered boaters. The integrated campaign has included the following: billboards, gas station advertising, radio advertising, online advertising, social media, print advertising, email marketing, outreach materials and boat ramp signage. In 2019, nearly $420,000 was spent on paid media that delivered more than 169 million impressions. The campaign is set to continue in the summer of 2020 with adjustments informed by the results of the 2019 campaign and by another online survey of registered boaters conducted during the summer of 2019.

* Efficacy of aquatic herbicides and combinations on redroot floater and Azolla in mesocosms

Sigmon, Joseph

University of Florida

Azolla pinnata and Phyllanthus fluitans are nonnative floating aquatic weeds. Azolla pinnata is a federally listed noxious weed present through the southeastern United States while Phyllanthus fluitans is not listed and is only present in Florida. Due to the floating nature of these plants there is the potential for crowding out other species as well as preventing resources such as light and oxygen from entering the water column. Because of these qualities these species pose a danger to the existence of native plants as well as the movement of water during flooding conditions. Evaluation of the proper herbicides needed to control these species was necessary. A study using mesocosms (plastic tubs) was developed to test the efficacy of thirteen different herbicides alone and in combination on Azolla pinnata and Phyllanthus fluitans. The plants were placed in the mesocosms at 80% coverage and exposed to different application rates of the herbicides and combination treatments. Four replications of each treatment were performed and the plants were harvested six weeks after treatment. The living plant material was then collected, dried in an oven, weighed, and compared to the untreated control replications. It was determined that in the case of both plants most herbicides were effective in reducing biomass by 90% or more. In the case of Azolla pinnata all treatments reduced biomass by 90% or more except fluridone, 2,4-D, and florpyr. In the case of Phyllanthus fluitans all treatments were effective in reducing biomass by 90% or greater except carfentrazone, fluridone, topramezone, and glyphosate. The results of this study indicate that a wide variety of herbicides are effective on treating these two species and persistence is most likely due to individuals escaping treatment.

More bang for your buck: Using less copper to control harmful algal blooms

Simmsgeiger, Patrick

Southwest Aquatic Services

Native plants play an important ecological role in aquatic ecosystems and can be an integral part of the lake management industry. Family-owned Southwest Aquatic Services, includes a licensed wetland plant nursery and is experienced in the use of native emergent plants in a variety of projects ranging from mitigation to enhancing pond aesthetics. This presentation will discuss experiences with the role of native emergent plants in our industry and the ups and downs of the wetland plant market in Texas. Additional topics will include Texas’ permitting and treatment proposal requirements related to restoration work.

CEU Drift Minimization: Maximizing your chemical investment… When bad things happen to good droplets! 

Smith, Chris 

WinField United

There is a need to make sure spray applications reach their target. Maximum coverage is needed for optimal pesticide performance. Maximum coverage is needed to reduce the movement of pesticides to non-target areas. There are many factors that affect whether a spray application reaches its target. Actions can be taken to reduce spray movement and ensure spray applications reach their target. Topics covered in this presentation include: What is spray drift? Why is reducing drift important? What factors affect spray drift? What can be done to limit spray drift?

* Procellacor efficacy on submersed plants at varying contact exposure times 

Thayer, Kyle L., Ian J Markovich, Joseph Sigmon, Mohsen Tootoonchi, and Lyn A Gettys

University of Florida

South Florida canal systems play an essential role for flood control. It is vital to maintain water flow in these systems, especially for a state that receives an average rainfall of 60 inches per year. Submersed vegetation must be managed frequently because they can quickly impede flow and clog drainage systems. Two invasive species, rotala (Rotala rotundifolia) and hygrophila (Hygrophila polysperma), are notorious for interfering with canal flow and causing management obstacles. ProcellaCOR SC (florpyrauxifen-benzyl 26.5%) is a recent product from SePRO that aims to control submersed aquatic plants. We conducted research to evaluate the efficacy of ProcellaCOR SC on rotala and hygrophila after varying contact exposure times (CETs). Plants were exposed to 0, 2.5, 5, 10, and 20 parts per billion of ProcellaCOR SC and then pulled, washed off, and placed into freshwater containers incrementally at 6, 24, and 48 hours after treatment (HAT). Weekly evaluations and pH levels were taken for six weeks. A destructive harvest was conducted of remaining live plant material and placed in a drying oven for one week to collect dried biomass readings. The concentration and exposure time needed for ProcellaCOR SC to reduce biomass in rotala and hygrophila by 50% or 90% was attained by dried biomass and visual quality data. This study confirmed that both plant species are sensitive to florpyrauxifen-benzyl. Rotala in particular is highly sensitive, even when exposed to extremely low concentrations for short periods of time.

*Tapegrass from different regions tolerates different amounts of salt

Tootoonchi, Mohsen, Lyn A Gettys, Kyle L Thayer, Ian J Markovich and Joseph Sigmon

University of Florida

Increased salinity can severely affect vegetation in freshwater ecosystems. Salinity of a waterbody can increase as a result of saltwater intrusion or by runoff/leaching from de-icing salts. Habitats that are deteriorating as a result of increased salinity can be restored with freshwater ecotypes (locally adapted populations) that tolerate above-normal salinity. These salt-tolerant ecotypes can be used to stabilize and revegetate marshes and wetlands. Tapegrass (Vallisneria americana) is a prominent species in many freshwater ecosystems and is commonly used in restoration efforts. Ecotypes of this species respond differently to other abiotic conditions such as light and fertility, so in this study we evaluated the effects of salt stress on 24 tapegrass ecotypes. Instant Ocean aquarium salt was used to create saline solutions [0.2, 2.0, 4.0, 10.0, 15.0 and 20.0 parts per thousand (ppt)], then plants were abruptly exposed to these solutions and maintained in these concentrations for 5 weeks before being visually assessed for quality and destructively harvested. Analysis of variance and non-linear regression were used to calculate LC50 values – the lethal concentration of salt that reduced plant biomass and quality by 50% compared to control treatment. Growth rate and visual quality varied significantly among ecotypes, and ecotypes that were most and least sensitive to salt had 50% biomass reductions at 0.8 and 9.1 ppt, respectively. Quality and growth of all ecotypes were negatively affected at 4.0 ppt, but all ecotypes survived salinity concentrations as high as 10.0 ppt. No ecotype survived 20.0 ppt, which suggests the maximum salinity concentration tolerated by these ecotypes is between 15.0 and 20.0 ppt.

Use of granular copper EDA (Harpoon) for Hydrilla control in Texas 

Westcott, Paul1, Kelly Duffie2, Dave Bass3, Bill Ratajczyk1, and Ryan Wersal4 

1Applied Biochemists, 2Helena Agri Enterprises, 3Lower Colorado River Authority, 4Minnesota State University

Copper EDA (ethylenediamine complex) has been a tool in aquatic plant management for many years, primarily as a tank mix partner with diquat for control of hydrilla.  Though effective, this combination imposes restrictions on water use following application. Over the past several years Applied Biochemists and our cooperators have worked to establish use patterns for copper EDA treatments for hydrilla control in both small and large scale 

applications.  Copper EDA treatments offer selectivity, impose no water use restrictions, and typically cost less per acre than combination or systemic herbicide treatments.  The granular formulation of copper EDA (Harpoon) offers some unique advantages where currents and water exchange can limit the efficacy of liquid aquatic herbicides. Lake LBJ is a 6,500 acre impoundment of the Colorado River about 45 miles northwest of Austin, TX.  A shallow, offshore submerged island, supporting 8 to 10 acres of hydrilla and completely surrounded by deeper water was chosen as a test site. The site’s open water location is subject to significant wind and wave action. Treatments using Haroon Granular at 240 pounds per acre (1ppm copper in bottom 3 feet) were completed by LCRA crews in mid-June and mid-July, 2017.  50-60% control was achieved following the first treatment, 95 -100% control occurred following the second treatment with no regrowth observed through late October.  

Proven efficacy, zero water use restrictions; including application to potable water sources, on-target A.I. release via granular formulation, and a favorable cost per acre compared with other options make copper EDA (Harpoon) a practical and effective choice for hydrilla control.

An inconspicuous invasive Hygrophila polysperma; Its ecology and identification

Williams, Casey


In Texas Hygrophila polysperma is generally considered an uncommon introduced aquatic plant. Until recently it was only known to exist in three locations: San Marcos Springs in Hays County, Comal Springs in Comal County and San Felipe Creek in Val Verde County. Hygrophila polysperma is a dominate member in the aquatic vegetation community of each system and has had well documented negative impacts to the local flora and fauna of these systems which includes endemic and endangered species. I recently published a record of new county locations for Hygrophila polysperma expanding its distribution into three new counties and two new river basins. It is likely that Hygrophila polysperma exists in other water ways across Texas yet has gone unnoticed. Hygrophila polysperma exhibits multiple growth forms ranging from terrestrial to semi aquatic to submersed. Hygrophila polysperma can be non-descript and easily overlooked. It can also be easily mis-identified as other species commonly found around Texas waterways. In this presentation I will provide a brief history of the species and discuss the ecology and life history of this plant. I will also highlight some key characteristics and comparative examples for identification to increase awareness of this species for water and ecosystem managers.

Native Texas aquatic plants: An overview and case studies

Williams, Casey


When one thinks of Texas, native aquatic plants do not usually come to mind. Yet Texas is home to an astounding array of native aquatic plant species. The diversity is a result of the varied topography and wide variety of eco-regions and micro habitats that span the state. And Texas is home to several rare and unique aquatic plants. For this talk I will highlight the diversity in aquatic plant species and their respective aquatic habitats. A few case studies of rare and unique aquatic plants will be highlighted as well. Finally, the importance of utilizing native aquatic plants in restoration projects and even home gardens will be discussed.