Timing, Defoliation Management, and Nitrogen Effects on Seed Yield of ‘Argentine’ Bahiagrass

Abstract

Seed yield of bahiagrass (Paspalum notatum Flugge) can be increased by burning the sward and applying N fertilizer at the proper time during the growing season. Our objective was to determine the optimum calendar month (photoperiod) for managing ‘Argentine’ bahiagrass pasture for seed production. Triplicate paddocks of a 10‐yr‐old Argentine bahiagrass pasture established on a Pomona fine sand (sandy, siliceous, hyperthermic, Ultic Alaquods) were grazed or not grazed (main plots) from October–February, 1988–89 and 1989–90, in a randomized complete‐block design. Cattle were removed from the area on 25 February. Then, on the 25th of February, March, April, and May (subplots) each year, portions of residue (sub‐subplots) were burned or mowed in both grazed and ungrazed fields. The residue removal dates corresponded with day lengths of 11.5, 12.3, 13.1, and 13.7 h, respectively. Immediately after residue removal, sub‐sub‐subplots (2.4 by 6.1 m) were fertilized with 0, 100, or 200 kg N ha−1. Mature raceme density, seed yield, and seed germination (1989 only) were determined in 1989 and 1990. Grazing did not affect any measured trait. Burning increased seed yield only for the 25 May 1990 treatment. Date of residue removal and N rate influenced (P < 0.0001) the number of mature racemes and seed yield interactively (P < 0.05). Nitrogen rate increased (P < 0.05) all measured traits in a quadratic manner when applied only during late‐April to late‐May. Results suggest that seed production from Argentine bahiagrass pasture in the subtropics could be enhanced with management implemented at day lengths >13.0 h.

Herbage Responses and Biological N2 Fixation of Bahiagrass and Rhizoma Peanut Monocultures Compared with their Binary Mixtures

“…'Argentine' is one of the most common bahiagrass cultivars planted in Florida (Trenholm et al, 2015), and it is known for its persistence under defoliation (Interrante et al, 2010) and good seed production (Adjei et al, 2000). Argentine is a tetraploid (Acuña et al, 2009) that forms a relative dense sod and has a dark green color (Trenholm et al, 2015).…”

Seed production of 'Mombasa' grass subjected to different closing cut dates and nitrogen rates

“…In some warm-season grasses, under varying defoliation management and N fertilization rates, estimates of the relationships between seed yield and its components have been addressed in the literature (Adjei et al, 2000;Lemke et al, 2003). Meanwhile, there are contradictory results regarding the responses of Guinea grass to CCD and N fertilizer.…”

Managing forage and turf‐type bahiagrass for seed production

“…Similar to other tropical grasses, bahiagrass exhibits both low seed yield and poor seed quality (Adjei & Mislevy, 1987; Adjei, Mislevy, & hason, 1992, 2000; Burton, 1942), characteristics that represent challenges for commercial seed production. The low seed yield and quality found in bahiagrass is due to a prolonged flowering period (Adjei, Mislevy, & Chason, 2000; Burton, 1942), nonsynchronous maturity of seeds on individual inflorescences (Burton, 1942), seedborne diseases (Burton & Lefebvre, 1948; Rios et al., 2015), low seed set and germination (Acuña, Blount, Quesenberry, Kenworthy, & Hanna, 2009; Rebozzio, Sartor, Quarin, & Espinoza, 2011; Rios et al., 2015; West & Marousky, 1989), and seed shattering (Burson, Correa, & Potts, 1978). Flowering in bahiagrass is genetically controlled and strongly influenced by both day length and temperature (Marousky, Ploetz, Clayton, & Chambliss, 1991).…”

“…Management practices aimed at increasing bahiagrass seed production include defoliation followed by fertilization (Adjei & Mislevy, 1987; Adjei et al., 1992, 2000; Gates & Burton, 1998). Although seed production was increased by early spring defoliation followed by N fertilization (Burton, 1943, 1944), such responses vary among cultivars and timing of treatment application (Adjei & Mislevy, 1987; Adjei et al., 1992, 2000; Gates & Burton, 1998). For Pensacola, early spring defoliation prior to emergence of the first inflorescence followed by an application of 50 kg N ha −1 produced high yields of high quality seed.…”

“…Defoliation of Argentine in late April and late May followed by N application at the rate of 100 kg N ha −1 produced high inflorescence density, seed yield, and seed germination. Increasing the N rate up to 200 kg N ha −1 in Argentine caused excessive foliage accumulation and depressed flower development and percent seed germination (Adjei et al., 2000).…”