Mike Lowery <lowery.mike@gmail.com>
Dudley Pond Preliminary 2016 Herbicide Treatment Recommendations Marc Bellaud <mbellaud@aquaticcontroltech.com> To: Mike Lowery <lowery.mike@gmail.com> Cc: Dominic Meringolo <DMeringolo@aquaticcontroltech.com>
Mon, Nov 9, 2015 at 11:09 PM
Mike, Attached are maps from our recent survey of Dudley Pond. We haven’t had a chance to prepare a more detailed report yet, but I wanted to send you the maps and provide my preliminary thoughts on treatment. As you already know there is varying density Eurasian watermilfoil (EWM) found throughout the littoral zone. We estimate that EWM growth is found throughout approximately 57 acres. Invasive curlyleaf pondweed (CLP) was found in a smaller footprint, but even more growth may be evident earlier in the season. While it is uncommon to see such extensive CLP growth in the fall, we did observe and hear reports of similar occurrences on other water bodies in the region. The most abundant native plant growth was claspingleaf pondweed. This is a heartier pondweed species that can be challenging to manage. While there are several herbicide treatment options available, based on past treatment experiences at Dudley Pond, recent experiences in other lakes and the current mix of plant growth, we believe that three options make the most sense. Sonar (fluridone) – has been used effectively in Dudley Pond in prior years. The most current research suggests that ultralow dose applications can be effective when applied early in the growing season and when utilizing the latest formulations. There is a new pellet formulation called Sonar H4C that has a lower percent active ingredient, so more pellets are applied per acre resulting in a more uniform coverage. There is also a new liquid formulation called Sonar Genesis that is absorbed by the plants more rapidly and results in more rapid plant response. We would recommend initiating treatment at the onset of active plant growth, probably earlymid April. Using the new liquid and pellet formulations should reduce the number of applications required and result in plant control by midsummer. We would expect excellent control of EWM, CLP and some thinning of the native plants including claspingleaf pondweed. The estimated cost for a Sonar treatment program would likely be in the range of $42,500$45,500. Reward (diquat) – effectively controls both EWM and CLP. It should also impact claspingleaf pondweed, but if enhanced control is desired then a tankmix with Aquathol (endothall) may be warranted. The disadvantage of using contactherbicides like diquat and endothall is that only seasonal control may be achieved. This needs to be weighed against the lower cost and the need to use other strategies such as diver handpulling to provide extended control of EWM. The total estimated cost for a diquat treatment would be in the range of $15,000 $20,000 depending on whether or not any endothall was required. Renovate (triclopyr) and Aquathol (endothall) combination treatment – this combination treatment approach has been used to target mixed communities of EWM and CLP. Considerable work has been done in the Midwest and in other areas. It allows for lower concentrations of each product to be used to provide the systemic benefits of triclopyr for EWM control and still control the pondweeds. Using triclopyr alone could be considered,
but this will not provide any control of CLP and other pondweeds and the cost would exceed that of using fluridone. Used in combination the cost may be slightly lower, but still may be in the range of $42,500. I am out of state at meetings until late tomorrow night, but wanted to get something off to you. Let me know if you have any questions and I’ll try to respond later tomorrow or on Wednesday. I should also be available for a call on Wednesday or Thursday if you’d like to discuss any of this in more detail. Regards, Marc
_______________________ Marc Bellaud President/Aquatic Biologist Aquatic Control Technology 11 John Road Sutton, MA 01590 508.865.1000 work 508.865.1220 fax 508.954.8577 cell mbellaud@aquaticcontroltech.com www.aquaticcontroltech.com
3 attachments Dudley15_Oct_MSPIC_ALM.PDF 3643K DudleyPd_nonTRG_ALM.PDF 3674K Dudley_Oct15_PCRISP_ALM.PDF 3758K
October 2015 Distribution of Native Aquatic Vegetation
Dudley Pond Wayland, MA
Data Collected: 10/15/2015 Map Prepared: 10/15/2015 For: Wayland Surface Water Qualty Committee Basemap © 2013 Esri
0
375 Feet
750
Legend
Nymphaea sp.
Potamogeton perfoliatus
Naiad flexilis
Vallisneria americana
±
21 West Main Street • Spencer, MA info@aquaticcontroltech.com 508-885-0101
October 2015 Density & Relative Abundance of E. Milfoil Legend
Dense (2.52 acres)
Moderate (5.86 acres) Sparse (22.83 acres) Trace (25.97 acres)
Dudley Pond Wayland, MA
Data Collected: 10/15/2015 Map Prepared: 10/15/2015 For: Wayland Surface Water Quality Committee Basemap © 2013 Esri
0
375
1:6,800
Feet
750
±
21 West Main Street • Spencer, MA info@aquaticcontroltech.com 508-885-0101
October 2015 Density & Relative Abundance of P. crispus
F G
Dudley Pond Wayland, MA
Data Collected: 10/15/2015 Map Prepared: 10/23/2015 For: Wayland Water Surface Quality Committee Basemap © 2013 Esri
0
375
1:6,800
Feet
750
Legend
F G
Individual Plant
Sparse
Moderate
Trace
±
21 West Main Street • Spencer, MA info@aquaticcontroltech.com 508-885-0101