INFLUENCE OF GRAZING FREQUENCY ON PRODUCTION AND QUALITY OF PASPALUM,BRACHIARIA, AND SETARIA GRASSES

Bahiagrass (Paspalum notatum Flugge) is the most popular perennial for age grass in Florida. However, its limitations include poor forage pro duction when temperatures are cool and day length is short, low qualit y forage, and stand loss due to mole crickets (Scapteriscus spp.). The purpose of this experiment was to screen three bahiagrasses, four Bra chiaria spp., and a Setaria cultivar at four grazing frequencies (GF) for dry matter (DM) yield, quality, total non-structural carbohydrates (TNC), and persistence. Experimental design was a split-plot arrangem ent of a randomized complete block with three replicates of GF (2, 3, 5, and 7 wk) as main plots and grass entries (Pensacola, Tifton-9, and Cycle-18 bahiagrass; B. brizantha cv. Marandu, B. decumbens, B. ruziz iensis, and B. humidicola; and Setaria cv. Kazungula) as subplots. Cru de protein (CP) and in vitro organic matter digestion (IVOMD) were mon itored in the spring of 1994 (following December to April forage accum ulation), and in June-July, August-September, October, and December fo r 1992 and 1993. Total nonstructural carbohydrates were monitored at t he beginning of the study and during December of each year Annual fert ilization was 170-15-57 kg ha(-1) N-P-K plus 1.7 kg ha(-1) Cu, Zn, Mn, and Fe and 3.4 kg ha(-1) S, with N split in March, July, and Septembe r. Warm season (May-December) DM yield of grass entries interacted wit h GF when pooled over 3 yr. Brachiaria decumbens, Cycle-18, and Tifton -9 bahiagrasses were among the highest DM yielders at all GF when pool ed over 3 yr, and also expressed the greatest DM decline between year 1 and year 3 at all GF. Brachiaria humidicola and Tifton-9 performed m ost favorably, with an overall increase in DM between year 1 and 3. Ge nerally, CP was higher in bahiagrass than Brachiaria forage and IVOMD higher in Brachiaria than bahiagrass forage. In general, B. humidicola produced good DM yields of quality forage and persisted well under th e wet (often saturated) soil conditions of central Florida.