Turf-Type Tall Fescue Fairways Reponse to Nitrogen and a Plant Growth Regulator.

Golf fairways represent the largest area of intensively managed golf course turf. If the goal in the golf industry is to reduce water, mowing, fertilizer and chemical inputs, alternative species must be studied. Durable species like turf-type tall fescue (TTTF) may be an option due to its high drought tolerance and capability to remain dense under low fertilizer regimes.  Research on TTTF for use on golf fairways has been limited.  Before TTTF becomes accepted some potential negatives like the wide leaf blades, rapid spring shoot growth, and potential for annual bluegrass (ABG) encroachment need addressed. One chemical method to alleviate these concerns is the application of a root absorbed plant growth regulator (PGR), which may result in more narrow leaves, reduced clipping production, while helping suppress ABG. A two-year field study was conducted on a research fairway dominated by a TTTF blend maintained at 1.8 cm to determine the effect of a multi-mode (Type I, II) PGR (flurprimidol + paclobutrazol + trinexapac-ethyl) and three nitrogen (N) rates (0, 74, and 147 kg N ha-1 yr -1) on appearance and ABG suppression when applied on 14 day intervals during active growth.  At the study initiation the plots contained approximately 25-30% ABG.  By July ABG declined to < 10% in PGR treated plots but by September rebounded to approximately 35% and 85% in the PGR and non-PGR treated turf, respectively.  The best appearance was associated wherever the PGR was applied. Nitrogen rate alone had no effect on appearance or ABG populations. This study demonstrates the feasibility of TTTF as a fairway species under low N for the cool-humid region.  Future studies should evaluate the ability of TTTF to tolerate golf cart traffic and also assess additional herbicide sensitivity.