Document Type : Research Paper
Authors
1 MSc student, Department of Horticulture Science and Landscape, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
2 Associate Professor, Department of Horticulture Science and Landscape, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
3 Professor, Department of Horticulture Science and Landscape, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
4 Assistant Professor, Department of Horticulture Science and Landscape, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
Abstract
Poinsettia (Euphorbia pulcherrima) is a potted plant, which its colorful bracts appear in short days. In this
experiment, effect of different ammonium to total nitrogen ratios on quantitative and qualitative traits of
poinsettia was studied. The experiment was conducted as a complete randomized design with three
replicates. The plants were irrigated with water containing of different ammonium to total nitrogen ratios
of 0, 0.05, 0.1 and 0.16. At the end of experiment, vegetative traits, fresh and dry weight of shoot and
root, chlorophyll index and mineral elements concentration were assessed. Overall study results revealed
that quality and quantity characteristics of poinsettia were significantly affected by various ammoniums
to total nitrogen ratios. So that, the maximum bract area and leaf area achieved for the ratio 0.05 meq/l
and the minimum achieved for the ratio 0.16 meq/l. Bract productions in plants delayed and its longevity
decreased by ratios higher than 0.05 meq/l. In addition, effect of treatments on fresh and dry weight of
bract, leaf, stem, and root and leaf nitrogen level was significant. According to the results, adjustment of
ammonium to total nitrogen in the nutrient solution with ratio of 0.05 meq/l likely makes improving in the
production characteristics of poinsettia.
Keywords: ammonium, bract, chlorophyll
Keywords
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