Comparison of Resin-coated and Soluble Fertilizer Formulations in the Production of Zonal Geranium, Potted Chrysanthemum, and Poinsettia

Abstract

<jats:p>A series of crop-specific, resin-coated, controlled-release fertilizer formulations, including: Sierra Geranium Mix 13-12-11 Plus Minors, Sierra Chrysanthemum Mix 12-10-17 Plus Minors, and Sierra Poinsettia Mix 12-12-15 Plus Minors were preplant-incorporated into Metro Mix 350 growing medium for the production of potted zonal geraniums, chrysanthemum, and poinsettia. Plant growth and foliar nutritional responses were compared to those obtained from plants produced with a standard resin-coated, controlled-release Osmocote formulation (19N-6P-12K), water-soluble Peters 20N-10P-20K, and a combination of water-soluble and resin-coated treatments. Crops produced with specialty resin-coated mixes (at recommended rate = l×) were equal in growth and flowering characteristics to those produced with Osmocote (1×), water-soluble (200 ppm nitrogen), or a combination of water-soluble (200 ppm nitrogen) and resin-coated (0.5×) fertilizer treatments. Foliar analyses revealed elemental concentrations in resin-coated fertilizer-treated plants were below those in water-soluble or combination treatments, but were within a range to support satisfactory quality crop production.</jats:p>

Whole-plant Response of Six Poinsettia Cultivars to Three Fertilizer and Two Irrigation Regimes

“…In recent years fertilizer recommendations have been reevaluated because nitrate leaching from intensive greenhouse production has become a major environmental concern (Biernbaum, 1992;Cabrera et al, 1993;Hershey and Paul, 1982). Poinsettias grown with a solution of 200 mg N/liter produced large plants with excessive foliar N levels (Tayama and Carver, 1992). Acceptable growth in poinsettias was achieved by lowering fertilizer applications via subirrigation to a constant rate of 125 mg N/liter , indicating that poinsettias can be grown successfully with 50% less fertilizer than is currently recommended.…”