Treatment Report. Professional Lake Management (PLM) was awarded a contract to manage Flowering Rush within the Pelican River Watershed District.

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1 Patrick Selter V.P. PLM Lake and Land Management 9/8/2008

2 Treatment Report Background Professional Lake Management (PLM) was awarded a contract to manage Flowering Rush within the Pelican River Watershed District. Flowering Rush is an exotic plant that has been introduced into several Minnesota counties. It is an aquatic plant that can grow as an emergent plant along shorelines and as a submersed plant in lakes and rivers. This exotic was likely brought to North America from Europe as a garden plant. Unfortunately, it also grows well in wet places. While single flowering rush plants are not a "problem," this exotic can form dense stands which may interfere with recreational lake use. Flowering rush may also crowd out native plants and in turn harm fish and wildlife. Pre Treatment The Minnesota Department of Natural Resources Ecological services staff mapped the locations of the Flowering Rush using GPS technology (Please see appendix 1). The GPS coordinates were then supplied to PLM. PLM in cooperation with the district and BASF the manufacturer of Habitat Herbicide met to discuss the application, how the product worked and the best application timing. It was determined by the recommendation of PLM and BASF that treatment be performed in mid to late August for several reasons. 1. Perennial plants are best managed at two times during the growing season. The first application time would be when the plant is young and before it sets seed. The second time is late in the growing season when plants begin to store energy and nutrients in the root structures. 2. The unique chemistry of Habitat applied later will allow more products to be taken into the root structure over winter. 3. Treating in August will ensure maximum exposure to the plants as they are at their peak and foliage is more available to be treated. Additionally water levels will likely be receding and even more foliage may be exposed above the water. Treatment The lakes determined to be infested and treated with Flowering Rush were Sallie, Melissa, Mill Pond, Muskrat, Curfman, and both Big and Little Detroit. Additionally the Pelican River which connects the lakes was determined to have sites with Flowering Rush. PLM determined that an airboat equipped with a hand gun and a boomless nozzle would provide the best method of treating since much of the areas were located in between docks and in very shallow water. Additionally the use of an airboat ensured that the treatments would not contribute to the spread of the Flowering Rush since there are no moving parts under the water surface to dislodge the plants. PLM also used a Lowrance LMS-17X GPS unit to track the treatment paths. Also on board the boat was a Raven variable rate controller 2 P a g e

3 which allows for precise application using the boomless nozzles. While using the handgun, the rate controller was not used to record since speeds would not be adequate to record. Lake Melissa Lake Melissa was the first lake to be treated. On August 18, 2008 PLM began treating the plants on Lake Melissa at 10:30 AM. Most of the plants were single clumps scattered around the shoreline. The south west bay and immediately south of the point had the most Flowering Rush and in some cases a continuous bed was noted. This lake was treated all by hand gun to ensure foliage was thoroughly wetted with a concentration of 1% Habitat and 1% Mentholated Seed Oil (MSO.) A total of.63 gallons of Habitat and.63 gallons of Metholated Seed Oil (MSO) were used on Lake Melissa. Areas treated were estimated at a total of 5 acres of spot treatment. Treatment was finished at 2:05 PM. Continuous bed Continuous bed Figure 1 Lake Melissa track log of treated areas La ke Sa llie Treatment of Lake Sallie began on August 18 at 4:30 PM. Beginning at the access site on the north shoreline and heading counter clockwise, PLM treated the entire North, West and South shoreline with a handgun. The Northeast shoreline was treated using the handgun and on August 19, 2008 the boomless nozzles were used to treat the near shore dense populations. A large section of the north east shoreline contained heavy dense Flowering Rush behind the vast Bulrush beds. PLM finished treating 3 P a g e

4 the North, West, South and a portion of the East shoreline around 7:00 PM. A total of 2 gallons of Habitat and 2 gallons of MSO were used to treat 8 acres of Flowering Rush. On August 19 th the remaining areas were treated using two boats. One boat was used to spot treat the outer edges of the Bulrush beds while the airboat worked the inshore beds of Flowering Rush. Treatment started at 11:00 am and was completed at 12:30 PM. The area treated was 6.6 acres and was treated with 3 gallons of Habitat and 2 gallons of MSO. Areas where the boomless nozzle was used outputted a mix of 34 gallons per acre with a concentration of Habitat at.5 gallons per acre was applied. Continuous bed approximately 20 feet wide Public Access Continuous bed approximately 20 feet wide Figure 2 Lake Sallie track logs of areas treated and dense area on inside of bulrush. Muskrat Lake Muskrat Lake had only a few plants located within the lake and the river section connecting from Detroit Lake to Muskrat had a few sites with Flowering Rush. On August 19 th, PLM began treatment of this lake at 8:00 AM and finished at 8:30 AM. Using Carolina Skiff boat, applicators inspected the sites and treated using a 2% Habitat and 1% MSO concentration by handgun. The reason for the increase in rate is that the plants were mostly isolated to 1 to 2 plants per site and a few sites where a multiple clumps were located. The area treated was approximately 1 acre and was treated with.19 gallons of Habitat and.1 gallons of MSO. The river section had a few sites however the biggest populations were limited to areas immediately adjacent to the two bridges. 4 P a g e

5 Several clumps along shore and around DNR dock Clumps on both sides of Bridge Figure 3 Muskrat Lake track log of treated areas Mill Pond Mill pond also only had a few plants scattered throughout. Mill Pond was treated on August 19 th and completed on August 29th. On August 19 th, applicators began treating at 9:30 AM by traveling the channel from Lake Melissa and finishing at 10:30 AM. It should be noted that applicators made several attempts to launch the airboat since there were points that were inaccessible by conventional boat. It was determined that a row boat with a hand sprayer would be needed to treat the additional shallow sites. On August 19 th applicators were able to treat several plants along the weed line, as well as immediately adjacent to the dam at the southwest side of the lake. Areas on the southeast side were treated on August 29 at 10:00 AM and finishing at 11:00 AM by rowboat and treating five to six plants. A Total of 1.25 acres were treated on Mill Pond over the treatment periods. A total of.26 gallons of Habitat and.20 gallons of MSO were used to treat the lake. 5 P a g e

6 Area treated by row boat Area treated by row boat Area treated by row boat Figure 4 Mill pond track log of treated areas from August 19 th Curfm an Lake Curfman Lake was treated on August 19 th and completed on August 27. On August 19 th applicators began treatment at 2:10 PM and finished at 5:00 PM. They treated the South and East shoreline due to a SSE wind which prevented treatment along the North and West shoreline. Flowering Rush was abundant in the Southwest corner and many spots were located throughout the Bulrush and bog areas. Most of the area treated was done using the hand gun. This allows applicators to effectively treat the Flowering Rush without impacting the Bulrush. The area along the East shoreline adjacent to the road was treated using boomless nozzle in combination with the handgun. The boomless nozzle was calibrated to spray 34 gallons of mix per acre with.5 gallons Habitat per acre and 1% MSO per tank. The average speed of the boat was 4.9 mph. On August 25 th applicators began treatment at 3:00 PM and finishing at 4:00 PM. On August 27 th PLM treatment began at 9:30 AM and finishing at 11:45 AM and was able to complete the North and West shorelines. The hand gun was used due to the fact that in the shallow water (less than 6 inches); boat wake was laying the plants into the water as the boat passed. This led to much slower speeds which could not allow for automatic rate control. Additionally, once away from shore, many of the Flowering Rush beds were spot treated. A Total of acres of dense and spot treatment took place on Curfman Lake over the treatment periods. A total of gallons of Habitat and 6.25 gallons of MSO were used to treat the lake. 6 P a g e

7 Dense Rush Dense Rush Figure 5 Curfman Lake track log of treated areas on August 19th Figure 6 Curfman treated areas Big Det roit Lake Big Detroit Lake was treated on several different dates due to wind conditions; starting on August 24 th and completing on August 27 th. On August 24 th applicators began treatment at 12:00 PM and finishing at 7:00 PM and was able to treat the East shoreline and a portion of the flats area. The areas were treated primarily with handgun since there was many clumps of Flowering Rush scattered throughout the areas. The East shoreline had the least amount of Flowering Rush with two sites with dense stands. A total of acres of spot and dense treatment was performed all using the handgun. The total amount of Habitat used was gallons and gallons MSO used on August 24 th. 7 P a g e

8 Figure 7 Big Detroit track log for Northeast shoreline along hwy 10 Figure 8 Big Detroit track log for South "flats" area On August 25 th applicators began treating the South shoreline beginning at the point from Curfman Lake. The treatment began at 7:00 AM and was completed at 11:00 AM. A dense and spot treatment area of Flowering Rush was treated for a total of 23.8 acres. The total amount of Habitat used was 8.9 gallons and 5.7 gallons of MSO. Dense near shoreline Dense near shoreline at some properties Figure 9 South Shoreline from Curfman On August 27 th PLM completed the spraying on Big Detroit Lake. Starting at 12:00 PM the Northwest shoreline of Big Detroit Lake was treated. This area is of concern because throughout the entire area there was only 8 to 10 inches of Flowering Rush plants above the surface of the water. This area was treated by both hand gun and in some areas boomless nozzle. The total area treated from highway 10 to the point going into little Detroit totaled 9.97 acres of spot treatment. The total amount of Habitat used was 4.98 gallons and MSO was 3.24 gallons. 8 P a g e

9 Figure 10 Areas along North Shore Drive The final area on Big Detroit Lake to be treated was the North portion of the flats There was heavy infestations extending from shore out to about 40 feet lakeward. Again the area was treated mostly with handgun due to the shallow water. A total of acres of spot treatment was performed in this area. PLM used 7.18 gallons of Habitat and 4.6 gallons of mentholated seed oil to treat this area. Figure 11 North Flats Area Little Detroit Lake Little Detroit Lake was also treated on separate dates. On August 25 th applicators began treating the south shoreline. Much of this area was spotty with a few locations of dense Flowering Rush. Treatment began at 11:30 AM and was completed at 1:30 PM. A total of 4.23 acres of spot and dense treatment was performed all using the handgun. The total amount of Habitat used was 2.16 gallons and the total MSO used was 1.4 gallons. 9 P a g e

10 Band of Rush approximately 25 feet wide Figure 12 South Shoreline of Little Detroit Lake On August 27 th from 2:00 PM to 4:00 PM applicators focused on the North shoreline of Little Detroit Lake. The heaviest infestation began at the point from Big Detroit and extended to the public beach areas. A total of acres of mixed spot treatment and dense treatment was performed almost entirely by handgun. A total of gallons of Habitat was applied and 7.84 gallons of MSO was used at a 1% concentration. Band of Rush approximately 20 feet wide Figure 13 Little Detroit Lake Total Managed Area The total area managed throughout the district was acres broken down into: acres of dense and spot treated area, acres of 20 feet bands, and 5.02 acres of individual plants. 10 P a g e

11 Observations PLM treated a total of acres of spot and dense area. The best results will likely be in the near shore areas where almost 100 percent of the plant was exposed to the treatment. There was an obvious sign of previous management as in some sites you could see distinctive lines where spray was applied in previous years. Applicators did notice several trees in which the lower portion had signs of non target damage likely from Habitat applications. It is unknown if this was due to root systems in the lake touching treated Flowering Rush or drift, the impact was minimal. It should be noted because the use Habitat herbicide can be directly related to this type damage. PLM took all precautionary measurements to ensure minimal impacts from drift, however if tree roots overlap treated plants this type of damage may be present. When you compare all the areas, Curfman Lake has the biggest infestation by scale. Almost the entire developed shoreline has Flowering Rush in dense stands. Detroit and Little Detroit seem to be significantly impacted due to the high use of these areas during the summer. Also in these areas the Flowering Rush will always be a challenge to manage due to the fact that there is less plant emergence and less exposure to the herbicide. There is an estimated 30 to 50 acres of submerged Flowering Rush in Detroit which, with the chemistries available and the little information available on Flowering Rush, will survive. Each year, new herbicide chemistries become available for aquatic environments and current products are being looked at for early season control of the submerged plant. Lake Melissa, Mill Pond and Muskrat have small populations of Flowering Rush which presented the challenge of finding them and determining if enough plant material was present for effective treatment. In a lot of areas only two to three stems of a much larger clump was emerged. Some of these areas were not treated simply because it would be completely ineffective and irresponsible plant management. Again these lakes could benefit from an early season control program. Recommendations for future management PLM would like to suggest the following management recommendations for future management of Flowering Rush within the Pelican River Watershed District. Development of Lake Vegetation Management Plans for each lake. A Lake Vegetation Management Plan would clearly identify the goals and objectives of the program and should include the use of the Integrated Pest Management strategy. Implement testing of all available products for early season control in high use areas where early season plants are problematic. Develop a Rapid Management Program for new infestations. This may include the use of hand digging single isolated plants especially in loose sediments such as Mill Pond. 11 P a g e

12 Develop a process for homeowners to report new infestations primarily on Lake Melissa, Muskrat and Mill Pond where populations have not expanded into dense stands. Figure 14 All Lakes Track Logs 12 P a g e

13 Figure 15 all Big Detroit 13 P a g e