MISSISSIPPI STATE -- First impressions count. For many visitors to Mississippi, the state's highways are the first thing they see and the condition of the roadsides can make a lasting impression.

A partnership between the Mississippi Department of Transportation and Mississippi Agricultural and Forestry Experiment Station scientists at Mississippi State University is helping keep roadways attractive for visitors and residents alike by management of rights-of-way vegetation.

"Since 1990, MAFES weed scientists have worked with MDOT personnel to find the right combination of herbicides and the most effective timing of applications to control grassy and broadleaf weeds along highways," said Mississippi State weed scientist John Byrd. "We also try to accomplish those goals without harming the desirable grasses along the rights-of-way."

Herbicides are tested on plots about 1,000 feet long and 100 feet wide along state highways. The researchers conduct about 15 to 20 experiments at locations throughout the state each year. Each plot is marked with "Do Not Mow or Spray" signs. The project also includes research with control methods for the invasive grass species cogongrass on plots near Preston in Kemper County.

Before the project, MDOT was using a combination of products to manage winter/spring weeds and applying them about the time the plants broke dormancy in the spring. The result was unsightly dead and dying vegetation along the state's highways.

The university research provides an independent source for information about products, according to MDOT state maintenance engineer John Vance.

"The research evaluates available chemicals and provides us with information such as rates and application timing," he said. "That's a real advantage for us."

The project also helps MDOT personnel stay abreast of developments in the chemical industry, such as when companies start manufacturing generic versions of formulations that have come off patent.

"Mississippi State University tests generic labels to see that we get the content we need, as well as the best price," said MDOT roadside development manager Dave Thompson. "The university work also has helped expedite label approval for products we need."

In addition to Byrd, current MAFES personnel working with the highway vegetation management project include research associates R. Scott Wright and James M. Taylor, graduate research assistants Keith D. Burnell and Bryan S. Peyton, and several student workers.

Their work also helps MDOT engineers with improved methods of removing vegetation that might impair visibility for drivers.