Research, Resources, Results

With these numerous challenges facing DOTs, partnerships with university researchers, conservation organizations, herbicide applicators and distributors are imperative to the success of a roadside vegetation management program. Purdue University researcher Dr. Zach Lowe sees the impact of this research as more DOTs look to stakeholder partnering for vegetation management solutions. “It's not that partnerships are a new idea,” he said, “But fighting invasive weeds today and finding unique solutions within tight budgets can require some very outside- the-box thinking and unique partnerships.”

Thinking outside the box at Purdue's research sites allows Lowe and his colleagues to work within the many disciplines involved in non-crop weed control and habitat management. Access to a diversity of sites that contain invasive and noxious weed problems give him an opportunity to reach out to agency experts and private interest groups, test the efficiency of herbicides and mowing equipment, and design plots that integrate weed control techniques with other long-term vegetation management solutions. All of this research results in a project that is focused on applied science and that shows real world applications of research. This can mean a big savings in time and resources for Midwest DOTs and other natural resource management professionals that are at the planning phase of management projects.

Weed science has developed over the past century primarily through the production agriculture industry, creating a useful set of tools that are intend to be applied to primarily cash crops on an annual cycle. Lowe points out that a diverse group of systems like roadsides and natural areas require an integrated vegetation management solution that combines the existing agrarian knowledge base about herbicides with principles from weed population dynamics and habitat management as well.

Roadside management involves different types of vegetation management criteria, including plants that are aesthetically pleasing, roadside-compatible wildlife habitat and undesirable invasive species that need well planned control strategies. Safety requirements, habitat restoration, mowing cycles, and the length of growing season all contribute to the challenge faced by DOT's when managing a roadside and controlling invasive species.

Unlike a relatively short-term vegetation management plan used for annual crop production, a comprehensive, long-range plan is key to making roadside areas manageable. “The more ‘natural' the area should be, or the longer you need to maintain it, the more difficult it becomes to sustain without creativity,” Lowe explained. “Managers really need to integrate multiple practices to keep up, including use of selective herbicides, well-timed mowing, and even seed selection in new plantings.”

Lowe also emphasized the importance of carefully choosing the balance of those elements of a weed control program, and developing a comprehensive plan to guide practices throughout the year. “In most cases, planning around the old spray and mow -by-the-calendar approach won't be enough,” Lowe said. “An integrated plan focuses on not only the use of herbicides, where they are appropriate, but how application timing after a mowing changes the efficacy of a product and the end-results on a target organism, such as invasive Canada thistle.”

Many invasive weeds, like Johnsongrass and Japanese knotweed, are actually stimulated by disturbances, like mowing, so managers need to understand the composition of each right-of-way before beginning any control program. This can be a daunting task for DOTs facing static or declining right-of-way weed management budgets. Progressive DOTs are reaching out to universities like Purdue to get the best understanding of treatments for their particular weed management scenarios.

Indiana's Department of Transportation, for example, utilized a portion of Lowe's research to find an integrated solution to their invasive brush problem on portions of their roadside. While the protocol of brush control and removal alone was clear, the DOT knew that re-vegetating these areas into favorable roadside habitat would require a unique approach. If the invasive brush was only controlled through a combination of herbicide and mechanical treatments it would result in an abundance of open growing space, ultimately resulting in the real chance of other invasive plants becoming established. Officials wanted to ensure the brush would be replaced with favorable native grasses that could be easily managed. After examining Lowe's research, they were able to find plausible treatment options to reach their goal.

“The staff at Indiana DOT understood what variables we were controlling and what products and techniques we were using to reach that end goal on the research site,” Lowe said. “By emulating some of those management techniques in their own vegetation management plan, but also adding their own experiences, the Indiana Department of Transportation has built a new integrated management plan that's been quite successful on the areas to which it was applied.”

Lowe's recommendations helped the Indiana DOT keep brush out and build a healthy stand of native grasses that require less maintenance and serve wildlife and motorist better.

Sparking new ideas through others' success

With many unique sites and test plots throughout the research farm, Lowe regularly invites visitors to see what the University is doing and what they can take away for their own vegetation management programs. He encourages DOT vegetation managers to see the Purdue test plots in person to view problem species and control mechanisms on the ground. This can help spark new ideas for the best treatments to produce the desired affect, from invasive plant management to native grass establishment programs.

“I rarely expect people to come to the project site, look at the plots and say ‘That's exactly the way it looks on my right-of-way.'” Lowe said. “But they can see something that looks comparable, and can often see the process we used to achieve our vegetation management goals by walking through several plots, from untreated control plots, to areas midway through treatments, and finally ‘completed' plots with several years' worth of results.”

Many natural resource managers take those ideas back to their own departments, tweak the treatments and build their own unique integrated vegetation management plan. They can also count on their university partners to provide unbiased analysis of equipment and herbicides in order to pick the right tools and management options for their sites.

A Pragmatic approach to partnership

Purdue is not the only university lending a hand to DOTs. In Kentucky, invasive Johnsongrass can grow to be almost 7 feet tall, becoming a major driving hazard and a serious control issue for the Kentucky Transportation Cabinet (KTC). By working with University of Kentucky Plant and Soil Science researcher Mitch Blair, the KTC was able to examine University test plots and find an integrated solution using herbicides that they could count on without investing more time in testing.

“Dealing with invasive weeds and a host of chemical treatment options, Mitch Blair takes a very pragmatic approach to look at the problems and develop partners to find a solution for Kentucky roadways,” said Lowe.

Blair provides the KTC with impartial recommendations on how to manage their roadsides, invasive species and even provides application training and other educational programs for the department's maintenance crews. “He is always eager to help, and to share the results of his work with regional stakeholders,” said Lowe. “That research can improve the overall health of the roadside ecosystem.”

Many vegetation management departments simply don't have time to keep up with all the new products and innovations in the industry. Like Blair's work in Kentucky, university research is valuable for more than just tank-mix recommendations. “During the KTC weed control annual meeting, we cover anything from sprayer calibration training, to weed identification, to label and safety issues,” said Blair.

Creating Public-Private Partnerships

When including herbicides in an integrated vegetation management plan, Lowe emphasizes how important partnerships are - even beyond the university campus - to demonstrate good stewardship practices when using chemicals.

Public-private partnerships can provide value beyond the herbicide of choice, including rate information and application techniques to apply the least amount of active ingredient necessary to reach management goals. “It is very important that DOT officials can identify and work with trusted partners to achieve their management objectives efficiently and effectively.” Lowe said.

For many herbicide application projects at Purdue, Lowe has partnered with Quality Vegetation Management™ (QVM) Certified Applicators, a program of BASF. In his native warm-season grass restoration work geared to Midwestern wildlife habitat restoration, Lowe partners with FDC Enterprises. As a QVM Certified Applicator, FDC wholeheartedly embraces the principles of creating and sustaining healthy habitats through professional, ethical and responsible practices. FDC leadership also invests heavily in innovative practices and ways to create efficiency, knowing that it will be both good for business and good for the ecosystem.

“Industry support, from companies like BASF, of the Purdue Research farm incorporates technical expertise and provides stakeholders like FDC with a baselines for quality management practices,” said Lowe. BASF continues its commitment to improving vegetation management and environmental stewardship of herbicides through value-added programs such as the QVM program and Project Habitat™ Awards. By building on the research programs of experts like Blair and Lowe, BASF and their QVM certified applicators are better able to provide high quality and environmentally sound herbicide services.

Lowe also works closely with BASF's herbicide specialists on herbicide treatment programs. “Randy Denhart, a BASF sales specialist, is able to see what I'm doing here in Indiana,what a herbicide applicator like Fred Circle is achieving in Ohio, and what Star Seed is doing to improve seed quality in Kansas,” Said Lowe. “By bringing all three together to develop an integrated vegetation management plan, Mr. Denhart becomes a fulcrum point of expertise in the industry, providing experience and know-how to the industry, it's customers, and other natural resource management groups to create these wonderful partnerships and innovations within the vegetation management community.”

Remembering the Big Picture

Like Mitch Blair, Zach Lowe takes satisfaction when his research is applied in large-scale projects. He learns from the broader applications, but he also sees the value of applying the weed control used in right-of-way areas to the larger Midwest ecosystem.

“Weeds don't respect borders, so we need to fight them on all fronts,” Lowe said. “The farmers installing conservation plantings can't expect much success if weeds in roadside areas aren't controlled, and visa versa. We won't ever completely get a problem weed population under control if we don't all work together. When our research at Purdue can assist in weed control at the ecosystem level, that's the best result for everyone involved.”

To learn more about Lowe's work at Purdue, visit:

To learn more about the Blair's work with the Kentucky Transportation Cabinet, visit:

Watch for more information about Lowe's CRP restoration work with FDC Enterprises in the Spring 2008 issue of Latitude magazine.

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