Tall fescue (Festuca arundinace Schred.) produces rapid growth during a 6- to 8-week period in early spring. A field experiment was initiated on tall fescue to determine the number of mowings that can be eliminated by the use of plant growth regulators (PGRs) during this rapid growth period. Primo (CGA 163935) applied at 0.4 kg/ha (0.36 lb/A) mid-March suppressed vegetative growth for 3 to 5 weeks and eliminated 3 mowings during the first 5 weeks after treatment during 1990 and 1991 and eliminated 2 mowings during 1993. Primo (CGA 163935) applied at this rate did not reduce the quality and density of tall fescue below the acceptable level. Primo (CGA 163935) applied at 0.8 kg/ha (0.72 lb/A) eliminated 1 additional mowing during the 5 weeks after treatment in 2 of 3 years when compared with the 0.4 kg/ha (0.36 lb/A) rate. However, turf quality was consistently lower for 6 to 7 weeks after the tall fescue was treated with the 0.8 kg/ha (0.72 lb/A) rate. Embark (mefluidide) applied at 0.42 kg/ha (0.38 lb/A) performed similarly to Primo (CGA 163935), except the quality and density of the turf were reduced below the acceptable level at various times during the study. There was no advantage in the use of Cutless (flurprimidol) plus Embark (mefluidide) at 1.1 + 0.14 kg/ha (1.0 + 0.12 lb/A) or paclobutrazole (PP 333) plus Embark (mefluidide) at 1.1 + 0.14 kg/ha (1.0 + 0.12 lb/A) on suppressing vegetative growth of tall fescue when compared with Embark (mefluidide) at 0.42 kg/ha (0.38 lb/A) alone. Neither Limit (amidochlor) at 2.8 kg/ha (2.5 lb/A) nor paclobutrazol (PP 333) at 1.1 kg/ha (1.0 lb/A) suppressed vegetative growth as effectively as Primo (CGA 163935) or Embark (mefluidide).

This content is only available as a PDF.

Author notes

Supported by state and Hatch Act funds allocated to the Georgia Agricultural Experiment Stations.

2Professor. The author thanks J. Davis, Station Statistician, for his cooperation in this study. The author also gratefully acknowledges the assistance of W. Olson, T. Dinkins, and M. Gilmer.