Date of Graduation


Document Type


Degree Type



Davis College of Agriculture, Natural Resources and Design


Wood Science and Technology

Committee Chair

David W. McGill.


Oriental bittersweet (Celastrus orbiculatus) is an invasive climbing, twining vine that can grow up into the forest canopy effectively inhibiting growth and light exposure on affected trees. A local landowner who had treated bittersweet with various rates of a glyphosate-based herbicide claimed that higher than recommended rates of herbicide were needed to effectively control the invasive plant. This study was established to assess the validity of this claim and to explore the interaction of glyphosate and surfactant effects on the efficacy of bittersweet control. The goal was to determine an ideal treatment of herbicide and surfactant rates for the effective chemical control of C. orbiculatus. Four rates of glyphosate herbicide in the form of Accord ConcentrateRTM (0%, 2.5%, 5%, and 10 % volume to volume) were crossed with four rates of a common surfactant (Cide-Kick IIRTM; 0%, 0.5%, 1%, and 2%) to create 16 treatments. Treatments were randomly assigned to individual plants growing in the understory of two forested areas in northern West Virginia. Five replicates for each treatment at each site were separated into discrete blocks to account for any microsite variation that might be present within the treatment area. Apart from the surfactant only treatments, all glyphosate treatments were highly effective in defoliating the bittersweet stems. This paper details the first-year results of the study and provides a glimpse of attributes that occur on this invasive species as a result of herbicide toxicity.