Comparison of Three Slow-release Fertilizers in the Production of Seedling Dwarf Date Palm

Abstract Phoenix roebelenii O’Brian palm seedlings were potted in Metro Mix 500, and 3 groups of 25 plants each were fertilized with 18–2.6–10 (8- to 9-month release), 19–2.6–10 (3- to 4 month release) Osmocote, and 21–2.6–10 (6-month release) Sulfur Kote. Control pots with and without plants were either fertilized or not fertilized. Seedling palms were greenhouse grown for 23 weeks at temperatures ranging from 18° to 41 °C. Fertilizer type had no significant effect on leaf number or length, total dry weight or root dry weight. Plants which received Osmocote formulations showed higher foliage dry weights than plants which received Sulfur Kote. Conductivity of leachate (EC = mmhos/cm 2 ) from pots fertilized with slow-released materials generally increased with no indication that release rate of nutrients had peaked.