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Seed yield and seed quality response of Pensacola and improved bahiagrasses to fertilization

Gates, R.N., Burton, G.W.
Agronomy journal 1998 v.90 no.5 pp. 607-611
Paspalum notatum, cultivars, seed quality, yields, forage, nitrogen fertilizers, phosphorus, potassium, NPK fertilizers, crop yield, seed productivity, application rate, Georgia
Availability of improved bahiagrass cultivars, such as 'Tifton 9', has increased the potential value of seed produced from bahiagrass. Seed yield response of improved entries to fertilizer inputs is unknown and the relationship of fertility to bahiagrass seed quality is poorly defined. Our objectives were to measure seed yield and seed quality response of three bahiagrass (Paspalum notatum Flugge var. saurae Parodi) entries, varying in forage yield, to fertilizer inputs. Bahiagrass was established in 1991 on Clarendon loamy sand (fine-loamy, siliceous, thermic Plinthaquic Paleudults) near Tifton, GA. Forage production had been evaluated from 1992 to 1994. In 1995 and 1996, seed was harvested from 'Pensacola', Tifton 9 (T9), and RRPS Cycle 18 (T18) in July. Eight fertilizer treatments, identical to the 3-yr forage yield study, included rates of 56, 112, 224, and 448 kg N ha(-1); 25 and 49 kg P ha(-1); and 47, 93, 139, 186, and 279 kg K ha(-1). Seed yield was lower (P < 0.01) in 1995 than in 1996 and year and fertilizer treatment interacted (P < 0.01). Seed yield achieved with 224 kg N ha(-1) and the lowest P and K rates was not improved by higher rates. Although fertilizer treatment and entry interacted (P < 0.01), optimal fertilizer inputs among entries were similar. Seed weight was greater in 1995 and was increased (P < 0.05) by spring application of 112 kg N ha(-1) compared with 56 kg N ha(-1), but not by higher rates. T18 seeds had greater (P < 0.05) emergence 7 or 14 days after planting (DAP) than Pensacola or T9. Emergence 14 DAP was greater with the highest N rates than the lowest rate. Emergence 35 DAP was only influenced year (1996 > 1995). Moderate levels of N enhanced seed yield. Fertilizer treatment had no important effect on seed emergence or dormancy. Seed production and cumulative emergence of the three entries were similar.