Year of Publication


Degree Name

Master of Science (MS)

Document Type

Master's Thesis


Agriculture, Food and Environment



First Advisor

Dr. Michael J. Lacki


Kentucky’s disappearing native grassland communities provide habitat for native flora and fauna. A study was conducted to compare the efficacy of herbicides in control of the invasive Japanese honeysuckle (Lonicera japonica) applied at times when most native species are dormant. Six herbicide mixtures (glyphosate, glyphosate + imazapyr, glyphosate + imazapic, imazapyr, triclopyr + difluphenzopyr, and metsulfuron + difluphenzopyr) were applied in three seasons to assess the effect of application timing of each mixture on honeysuckle control. Herbicides were applied with a CO2 pressurized sprayer at three sites in a randomized complete block design. Pretreatment sampling indicated that Japanese honeysuckle constituted over 70% of plant cover at the study sites. Post-treatment sampling was conducted 60 days, 180 days, 420 days, and 540 days after the final application. All mixtures decreased percent cover of honeysuckle with varying effectiveness. Results indicate that the glyphosate, imazapyr, and metsulfuron + difluphenzopyr mixtures are particularly effective at controlling Japanese honeysuckle when applied at any time between October and April with suitable temperatures. Many native grasses and broadleaf forbs not found during pretreatment sampling also emerged post-treatment, either benefiting from application timing or indicating herbicide tolerance.