Improvement of the Growth of Potted Cyclamen Grown in Cedar Bark Medium Amended with Surfactant and Iron Sulfate

Abstract

We cultured cyclamen (Cyclamen persicum Mill.) using cedar bark as a potting medium. The cedar bark comprised 12% solid phase, 55% liquid phase, and 32% gaseous phase; with a bulk density of 0.15 g·mL⁻¹ and pH 6.13. Application of nonionic surfactant (AquaGro 2000L) increased hydrophilia of cedar bark. With trickle irrigation, amendment with surfactant had no effect on the growth and flowering of cyclamen (medium-flowered cultivar ‘F₁ K Middy Chorus’) grown in 15-cm pots. However, with flood and drain irrigation, amendment with surfactant controlled the rise of moisture tension and water repellency of cedar bark, which prevented wilting and improved plant growth. Soaking cedar bark with 0.3% FeSO₄·7H₂O markedly improved growth and flowering of cyclamen plants grown in 15-cm pots (for the medium-flowered cultivar ‘F₁ K Middy Chorus’) with trickle irrigation and in 9-cm pots (for the small-flowered cultivar ‘F₁ Miracle Deep Rose’) with flood and drain irrigation. It seems that tannin, which inhibits root growth, was inactivated by binding with Fe, and thereby plant growth improved.