822 PB 269 PINE BARK SOIL AMENDMENTS AND NUTRITION AFFECT GROWTH AND DROUGHT TOLERANCE OF VIBURNUM PLICATUM VAR. TOMENTOSUM `MARIESII'

in HortScience
View More View Less
  • 1 Department of Horticulture, University of Georgia, Athens, GA 30602.

Container-grown Viburnum plicatum var. tomentosum `Mariesii' were planted in tilled beds and tilled beds amended with aged pine bark. After transplanting, plants were fertilized at three different rates: no fertilizer, 18.4 g of N m-2, and 36.8 g of N m-2. A 31 day drought was begun 73 days after planting. Fertilization of tilled plots induced ammonium toxicity, which caused a linear reduction in leaf area, shoot dry weight, and root dry weight. Fertilization of amended plots had no effect on shoot growth but reduced mot growth by 54%; thus, amendments ameliorated ammonium toxicity. Between 10 and 28 days after beginning the drought, plants in unfertilized-amended plots maintained higher relative leaf water contents (RLWC) and relative leaf expansion rates (RLER) than plants in unfertilized-tilled plots. Amendment induced nitrogen deficiencies contributed to the increased drought tolerance of plants from unfertilized-amended plots. Since fertilized plants developed symptoms of ammonium toxicity, we were unable to determine if increasing fertility would counteract the drought tolerance conferred by pine bark soil amendments.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 38 11 2
PDF Downloads 72 26 3