Flowering Rush Research 

In 2010, the District gathered experts from around the US to form a collaborative effort to research the growth cycle, habitat, and herbicide options to better understand Flowering Rush and develop better management strategies.  The partnership included the Pelican River Watershed District, Mississippi State University Geosystems Research Institute (GRI), Concordia College (Moorhead, MN), US Army Corps of Engineer Research and Developments Center (USACERDC), and the Minnesota Department of Natural Resources - Ecological and Water Resources Division.

In order to most effectively reduce Flowering rush populations, submersed (below water surface) flowering rush was targeted for the treatment research project. The growth cycle and habitat studies were used to refine herbicide application timing and water depths for treatments.  Small-scale herbicide trials and an in-lake dissipation study were conducted in 2010-11.  Based upon these promising results, in 2012, the first operational-scale of Flowering rush in-lake treatments were conducted on Detroit, Curfman, Sallie, and Melissa lakes.  In 2013, the treatment areas were expanded due to the significant reduction of below surface plants and roots following treatment with limited impact on native plant species. In 2015, the District began adapt the management plan to reduce the frequency of treatment for low density areas.  Currently, the District treats populations annually with the adaptive management plan. 

FR before.jpg

Before

FR after.jpg

After

 

Flowering Rush Research Collaboration Summary Notes - 2012

Ecology and Phenology of Flowering Rush

 Ecology of Flowering Rush in the Detroit Lakes Becker County, MN - Marko, Madsen, Olson, Smith-2012

 Ecology and Management of Flowering Rush in Detroit Lake, MN -Madsen, Wersal, Marko, Skogerboe- 2012 

Flowering Rush Ecology and Phenology Summary 

Herbicide Trials

Evaluations of Contact Aquatic Herbicides for Controlling twp Populations of Submersed Flowering Rush

Summary of Evaluations of Contact Aquatic Herbicides - 2011 

Evaluations of Systemic Aquatic Herbicides for Controlling two Populations of Submersed Flowering Rush

Herbicide Trials for Management of Flowering Rush in Detroit Lake, MN for 2011

 Herbicide Trials for Management of Flowering Rush in Detroit Lake, MN for 2012

Efficacy of combinations of diquat or triclopyr with flouridone for control of flowering rush

Lake-wide Herbicide Treatments

Management of Flowering Rush using the Contact Herbicide Diquat in Detroit Lake, MN for 2013

Management of Flowering Rush using the Contact Herbicide Diquat in Detroit Lake, MN for 2014

The work and research that was done in the Pelican River Watershed District was used in an paper that was published in 2016 in the Journal of Aquatic Plant Management, Management of Flowering Rush in the Detroit Lake, MN

Developing an Adaptive Management Plan for Flowering Rush 

2014 Adaptive Management of Flowering Rush using Diquat Final Report

Detroit Lakes 2015 Pre-Treatment survey: Summary and Treatment Recommendations

2015 Adaptive Management of Flowering Rush using Diquat Final Report

2016 Adaptive Management of Flowering Rush using Diquat Final Report

Treating Mixed Stands of Flowering Rush and Bulrush on Lake Sallie

In 2015, the District began a 2-year pilot study to treat mixed stands of Flowering rush and native hardstem Bulrush on the east side of Lake Sallie.  Flowering rush was invading and displacing a 60-acre area of critical hardstem bulrush habitat.  The study involved a small 5-acre test plot and concluded treatments had no damaging effects on the native Bulrush and  significantly  reduced Flowering Rush populations.  Other native plant species such as the Pond Lily reestablished in the treated areas. The treatment areas were expanded  to 23 acres in 2017 and treated the entire mixed stand areas (approximately 60 acres) starting in 2018. 

The Effects of the contact Herbicide Diquat on Mixed Stands of Flowering Rush and Hardstem Bulrush in Lake Sallie 2015

 



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PRWD in the News

PRWD/MN DNR Zebra Mussel impact study

MPR News Story on PRWD Flowering Rush Project

Dan Gunderson, MPR News, visited Lake Sallie with Brent Alcott to discuss the success of the…

MnDNR begins ZM pilot project treatment


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Recent Water Levels
Detroit 1334.58 ft
Last Updated: 5/20/2020
Floyd(s) 1354.8 ft
Last Updated: 5/4/2020


Melissa 1328.893 ft
Last Updated: 5/20/2020
Sallie 1329.75 ft
Last Updated: 5/20/2020

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