Timing, Defoliation Management, and Nitrogen Effects on Seed Yield of `Argentine' Bahiagrass
- Martin B. Adjei *a,
- Paul Mislevya and
- Wallace Chasonb
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.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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