Although seed yield of bahiagrass (Paspalum notatum Fluegge) can be increased by burning and N fertilization, there is a need to establish the optimum stage of plant development for the application of such practices. A ‘Pensacola’ bahiagrass pasture, grown on Pomona fine sand (sandy, siliceous, hyperthermic, Ultic Haplaquods), was either burned or mowed at five stages of plant development: dormant, early vegetative, first‐raceme‐visible, and 2 or 4 wk after first‐raceme‐visible. After residue removal, plots were fertilized with 0, 50, or 108 kg ha−1 N. Seed yield, number of inflorescences, seed weight, and seed quality (1987 only) were determined in 1987 and 1988. Stage of plant development at time of residue removal affected all traits (P ≤ 0.05). Seed yield, seed weight, and seed quality were highest when residue was removed at the dormant or early‐vegetative stages of plant development. Seed dormancy, however, decreased as stage of plant development increased. Method of residue removal (burn vs mow) did not significantly (P ≤ 0.05) affect any trait except number of inflorescences in 1987, when more inflorescences were produced following mowing than burning. Nitrogen fertilization significantly (P ≤ 0.05) increased seed yield and number of inflorescences, but had no affect on seed weight or seed quality. Residue removal by burning or mowing prior to the first‐raceme‐visible stage of plant development, followed by application of 50 kg ha−1 N, produced high yields of quality bahiagrass seed.

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.

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