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Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/12/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Pensacola bahiagrass, covering 5 mil acres is one of the most resilient pasture grasses used in the Southeast and also benefits subsequent crops by reducing nematode or soil-borne diseases when used in rotation. The primary limitation to using bahiagrass for rotations or pastures is slow establishment. Yield can be increased by improved varieties like Tifton 9, or experimental RRPS cycle 18, selections from Pensacola. Accelerated aging and priming seed treatments did not improve bahiagrass establishment in previous research. Little information about bahiagrass management for seed production is available. We conducted research for 2 yr to examine the seed yield response of Pensacola, Tifton 9 and RRPS cycle 18 to fertilization. Seedling emergence was evaluated to determine whether any nutrient level might improve bahiagrass establishment. Seed yield increased with nitrogen rates up to 200 lb/acre, but increases above 100 lb were modest; 400 lb/acre was not beneficial. The lowest levels of P205 and K20 were sufficient for optimum seed yield. Bahiagrass germplasms responded similarly to fertilizer. After 35 days, seedling emergence was nearly identical for all treatments. Fertilizer management for seed production did not contribute to improved bahiagrass esablishment but this research provides seed producers with the only information available for fertilization of Tifton 9 and improved bahiagrasses for seed production. Technical Abstract: Our objectives were to measure seed yield and seed quality response of 3 bahiagrass (BG) entries (E), varying in forage yield, to fertilizer inputs. BG was established in 1991 on Clarendon loamy sand near Tifton, GA. Forage production was evaluated from 1992-1994. In 1995-1996 seed was harvested from Pensacola (P), Tifton 9 (T9) and RRPS Cycle 18 (T18) in July. Six replications of a split-plot design of E whole plots and fertilizer treatment (F) subplots (1.8 x 5.4 m) were used. Eight F, identical to the 3 yr forage yield study, included rates totalling: 56 to 448 kg N ha-1; 24 to 49 kg P ha-1 and 47 to 279 kg K ha-1. Seed yield was lower (P<0.01) in 1995 than 1996 and yr and F interacted (P<0.01). Seed yield achieved with 224 kg K ha-1 and the lowest P and K rates was not improved by higher rates. Although F and E interacted (P<0.01), optimal fertilizer inputs among E were similar. Seed wt was greater in 1995 and was increased (P<0.05) by spring application of 112 kg N ha-1 compared to 56 kg N ha-1 but not by higher N rates. T18 seeds had greater (P<0.05) emergence 7 or 14 d after planting (DAP) than P or T9. Emergence 14 DAP was higher with the highest N rates than the lowest rate. Emergence 35 DAP was only influenced by yr (1996>1995). Moderate levels of N enhanced seed yield. F had no important effect on seed emergence or dormancy. Seed production and cumulative emergence of 3 E were similar. |
