RESPONSE OF TIFTON-9 PENSACOLA BAHIAGRASS TO HARVEST INTERVAL AND NITROGEN RATE

Pensacola bahigrass (Paspalum notatum Flugge) is the most widely grown warm-season perennial pasture grass in Florida. It is very tolerant t o a wide range of management practices and is persistent under unfavor able conditions such as low fertility and heavy grazing pressure. Tift on-9 is an improved cultivar of Pensacola bahiagrass with a more uprig ht growth habit and greater forage production potential than Pensacola . Experiments were conducted to determine the response of Tifton-9 to nitrogen rate and harvest interval (HI) and to determine the interacti ons of N and rate x HI. A N rate experiment contained N rates of 0,84, 168, 336, and 672 kg ha-1 total N for the season in split application s at 4 wk intervals. Forage production increased as N rate increased w ith a lower response above the 336 rate. In a second experiment, forag e was harvested at 1, 2, 4, 8 and 16 wk intervals with N rate constant at 336 kg ha-1 N. Highest forage production for the season was at the 8 week HI. Relative production for the 1, 2, 4, 8, and 16 week HI was .35,.53,.81, 1.00, and.75 respectively. Although forage production was much lower with a 1 or 2 week HI, stand of the sward was not reduced. A third experiment was a factorial with 2 N rates (168, 336 kg ha-1) and 3 HI (2, 4, 8 wk). Relative forage production for HI/N rates of 2/ 168, 2/336, 4/168, 4/336, 8/168, 8/336 was.35, .53, .52, .76, .84, 1.0 0 respectively. These data can be useful to livestock producers in dev eloping forage utilization systems to maximize nitrogen efficiency.