In the past, NCDOT has used a combination of chemical and mechanical weed control management strategies under and around over 1000 miles of median rail that have proven to be time consuming and expensive to implement. Zoysiagrasses are known to be a thick sod-producing turfgrass that once adequately established have minimal weed invasion. Zoysiagrass germplasm that can be established quicker using sprigging methods may provide a solution to their establishment and long-term maintenance. Thus, this project was conducted to evaluate different varieties, methods and timings for establishment of zoysiagrass on roadsides.
These evaluations were done on NC roadsides in different climatic regions of NC. For one objective, cultivars were seeded or sprigged at different timings (fall -September, October, November- or spring -March, April, May). Zoysiagrass planted via seed was faster to establish with greater coverage for both location and all timings compared to sprigging. Although establishment and coverage from sprigging material was not rapid, it should be noted that zoysiagrass sprigs were able to show comparatively similar coverage to seed plantings after about 12-18 months. A secondary objective was to evaluate fall and spring zoysiagrass establishment using two large-scale sprigging units: an older, disk-driven sprigger that incorporated sprigs below the soil surface, and a newer sprigging unit that leaves sprigs on the soil surface. Cover materials of excelsior mat, coastal bermudagrass straw, and an uncovered control were applied as split plots. Results suggest the limitation in large-scale sprigging equipment use for establishing zoysiagrass may be impacted more by limited available water than the type of equipment. For the third objective experimental materials were tested against commercial cultivars for their ability to establish faster under minimal inputs. Differences in establishment were identified and two experimental lines showed significant promise for us on NC roadsides. Overall, results from this research suggest that zoysiagrass can be established on NC roadsides with minimal inputs but additional research is needed to refine the methods to increase sprigging success.
