HERBICIDE DEVELOPMENT AND USAGE FOR HIGHWAYS. FINAL REPORT ON PHASE 2

Fourteen separate trial sites were established in Georgia during a three-year period (1981-1983). The purpose of various trials ranged from a search for herbicides which could be substituted for MSMA for bahiagrass suppression, to fescue seedhead suppression, to annual grass and broadleaf weed control, to johnsongrass control, and to testing of new application technology with controlled droplet applicators. Glyphosate (Roundup) was found to be a good substitute for paraquat in tank mixture with hexainone (Velpar) or bromacil (Hyvar) for weed control in cracks of aged asphalt surfaces. Glyphosate (Roundup) at 0.25 lb. ai/A was proven to be equivalent to MSMA at 2 lbs. ai/A for bahiagrass suppression, with good tolerance in common and Coastal bermudagrass. Sethoxydim (Poast) also was found to have good potential for bahiagrass suppression at rates between 0.22 lb. ai/A and 0.37 lb. ai/A, varying from minor to major injury to common or Coastal bermudagrass. Centipedegrass was also found to be tolerant to sethoxydim, sulfometuron (Oust), and DPX-6206. Several large and small trials were conducted on fescue and bahiagrass for seedhead supression and other effects. EPTC (Eptam), mefluidide (Embark), sulfometuron (Oust), DPX-6206 and DPX-T6376-21 gave good to excellent suppression of fescue seedheads. Sulfometuron, DPX-T6376-21, and DPX-6206 gave excellent suppression of bahiagrass seedheads. Extensive trials in two locations with sulfometuron (Oust) for winter annual grass and broadleaf control, bahiagrass suppression and johnsongrass control indicated time of application was critical. Several winter annual and summer perennial species are tolerant to sulfometuron. Test runs with Controlled Droplet Applicator (CDA) nozzles compared with flood nozzles and off-center (OC) nozzles indicated a significant reduction of spray drift potential with CDA nozzles. Several herbicides not presently labelled exhibited potential for use on highway rights-of-way, including DPX-6206, DPX-T6376-21, Dowco 453, triclopyr (Garlon), and sethoxydim (Poast). (Author)

• Corporate Authors:

  University of Georgia, Athens

  College of Business Administration
  Athens, GA  United States  30602

  Georgia Department of Transportation

  One Georgia Center
  600 West Peachtree Street, NW
  Atlanta, GA  United States  30308

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Miller, J F
  • Middlebrooks Jr, P B
• Publication Date: 1984-4

Media Info

• Features: Appendices; Tables;
• Pagination: 52 p.

Subject/Index Terms

• TRT Terms: Grasses; Herbicides; Highway maintenance; Measures of effectiveness; Roadside; Sprays (Materials); Weed control
• Uncontrolled Terms: Effectiveness
• Subject Areas: Design; Environment; Highways; Maintenance and Preservation; I61: Equipment and Maintenance Methods;

Filing Info

• Accession Number: 00391647
• Record Type: Publication
• Report/Paper Numbers: FHWA/GA-84-7701, GDOT-7701
• Files: TRIS, USDOT, STATEDOT
• Created Date: Jan 30 1988 12:00AM