Nina Payne works in a tree nursery with nutsedge control trials.
A study led by Nina Payne, an Auburn University College of Forestry, Wildlife and Environment (CFWE) research scientist, is providing a long-awaited solution to one of the most ongoing and costly problems affecting southern pine nurseries: nutsedge control.
Nutsedge reproduces through underground rhizomes and nutlets. One nutsedge plant can produce thousands of nutlets in a growing season.
For years, nursery managers have struggled to control the aggressive weed, which competes with pine seedlings for nutrients and dramatically increases labor costs. Until now, no herbicide approved by the Environmental Protection Agency (EPA) could be used over the top of the pine seedlings without damaging them, forcing nurseries to rely on more time-consuming and labor-intensive practices.
Payne, a researcher with the CFWE’s Southern Forest Nursery Management Cooperative (SFNMC), spent more than a decade working to change that under the leadership of former SFNMC Directors Scott Enebak and Annakay Newell.
For over 50 years, the member-based SFNMC has been at the forefront of advancing southern pine seedling production. Born out of a need to solve urgent pest and disease challenges, it has united nursery leaders from industry, state agencies and the U.S. Forest Service to pioneer practical, science-backed solutions.
Today, the SFNMC is advancing what might be its most critical discovery yet.
“Prior to this research, there were no herbicides available to industry that could safely control nutsedge in southern pine seedling nurseries,” Payne said. “This weed is the most problematic and costly to control in bareroot nursery systems.”
Building on decades of prior research dating back to the 1970s, Payne began testing new herbicide options in 2014. Over 12 years, she managed 26 field trials and evaluated 14 herbicides in operational nursery settings.
Nina Payne sifts through soil looking for nutsedge nutlets.
Through teamwork with industry partners, including Eric Reasor of PBI-Gordon, Payne identified two herbicides, Arkon™ and Vexis®, as safe solutions. Both products have the active ingredient pyrimisulfan, which was found to control nutsedge without harming pine seedlings.
Payne’s discovery marks a major advancement for nursery operations in the Southeast.
In May 2026, PBI-Gordon began the EPA labeling process for Arkon, a key step that would allow nurseries to legally apply the herbicide in loblolly and slash pine seedling beds. The approval process requires coordination between the manufacturer, the SFNMC and state agriculture departments.
If approved, the herbicide could significantly reduce both the cost and labor demands for growers.
Pine seedlings being shown against clipboard to show growth
As of now, many nurseries depend on hand-weeding during peak infestations; an expensive practice made more difficult by ongoing labor shortages. Payne estimates that nurseries dealing with nutsedge could save more than $50,000 annually by adopting the new herbicide solution. Across SFNMC member nurseries, total savings could exceed $1 million per year.
Beyond economic benefits, the research also offers environmental advantages. By improving herbicide efficiency, nurseries will require fewer applications over time, which reduces the overall amount of chemicals applied to the soil. This leads to a more sustainable approach to producing high-quality seedlings for reforestation efforts.
Loblolly pine seedlings grow during nutsedge trials.
“Bareroot pine growers will be able to more effectively control nutsedge while producing higher quality seedlings with fewer inputs,” Payne said.
The research effort was highly collaborative, involving efforts from 5 nursery partners that provided land, labor and operational support for field trials. Auburn’s SFNMC staff members, along with CFWE students, conducted data collection and herbicide application methods, while College of Agriculture horticulture department experts assisted with regulatory processes.
To make sure the herbicide was safe for pine seedlings, Payne and her team tested pyrimisulfan at different rates and at six stages of seedling growth. Running these trials in real nursery settings helped them learn exactly when and how the herbicide could be applied without causing damage.
Pyrimisulfan was originally created for rice production and is now used in turfgrass. The SFNMC often tests products from agriculture, turf and landscape horticulture when forestry‑specific options don’t exist. This approach has become an important way to find new tools for nursery managers
Richard Cristan, director of the SFNMC, said the success of the project reflects years of persistence and teamwork between academia and industry.
“The collaboration between Auburn and the SFNMC members was essential to moving this process forward to EPA review,” said Cristan. “Once approved, these findings will represent a major step toward improving efficiency, sustainability and profitability in southern forest nurseries, while helping guarantee a steady supply of healthy seedlings for future forests.”
