Nutritional Influences on Cold Hardiness of St. Augustinegrass {Stenotaphrum secundatum)
1972
Reeves, Sim A. | McBee, George G.
The study was designed to determine the effect of latefall fertilization on winterkilling of St. Augustinegrass (Stenotaphrum secundatum). Data on which to base recommendations for late-season fertilization of this grass in the South are inadequate. N, P, and K, and combinations of these were applied at different intervals at the rate of 1.47, 0.64, 1.23 kg/100 m³/mo, respectively, through December 1968 to plots in the College Station area. Plots to which N was applied in November and December showed the greatest topkill after each freeze, but were the first to resume growth when the temperature increased. Late application of N fertilizer, either in combination with P and K or separate, resulted in the grass remaining green longer in the fall and resuming growth faster in the spring. St. Augustinegrass lost the majority of its cold hardiness between 48 and 72 hours at 25 C under the conditions of this study. Samples of tissues were collected to determine levels of the above-named elements that were present. Chemical analysis of material collected before the first freeze showed higher N levels in the tissue under late N fertilization. A direct relationship appeared to exist between the tissue N level and levels of K and P. Where higher levels of tissue N were obtained, generally higher levels of P and K were also obtained.
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