| Summary: | 碩士 === 國立臺灣大學 === 園藝學研究所 === 100 === Anthurium andraeanum Lind. is one of the most important floricultural crops in the world. European and American countries have used ebb-and-flow (E-F) irrigation system for potted plants production. Recycle nutrition in E-F can reduce water and fertilizer usage and avoid fertilizer leaching and water pollution. Although anthuriums have been produced commercially using E-F, related scientific reports are limited. The objectives of this study were to investigate the nutrient solution, media, and shading on growth and flowering of Anthurium ‘Pink Champion’ under E-F system.
Five concentrations of Johnson’s solution were applied under E-F or hand-watering irrigation system. For both irrigation methods, the best leaf and flower growth occurred in plants with 25%. The ratio of flower dry weight to total dry weight was higher in E-F than in hand-watering. Higher nutrient concentrations (50% to 100%) led to salt-injury symptoms, with marginal necrosis of the leaf tip and discolored spathe lobe. The symptoms were expressed more as the nutrition concentration increased. Leaf N, P, K and Ca concentrations increased, leaf Mg decreased, as solution concentration increased. Leaf macro-element contents were saturated in plants with 50% or higher concentrations. When applied with 75% or 100%, E-F had higher electrical conductivity (EC) of the upper portion of the medium than hand-watering. However, the EC of middle and bottom portions did not differ between two irrigation methods.
Five nitrogen concentrations were applied to anthurium plants cultivated in peat- or coir-based medium. Maximum growth was obtained in plants grown in peat- or coir-based medium with 4 and 8 mM N. Plant growth did not differ between peat- and coir-based media. Under 16 mM N, leaf and flower dry weight were lower in coir-based medium than in peat-based medium. The medium pH was 6.0 and 5.7 when applying 0 and 4 mM N in peat-based medium, respectively, while pH decreased to 3.4 to 4.6 in coir-based medium.
Five NH4＋:NO3－ ratios (0:100, 25:75, 50:50, 75:25, and 100:0) did not significantly affect on leaf and flower growth. However, the numbers of chlorotic spot and/or necrotic leaves, discolored spathes, and necrotic flowers increased as NH4-N ratio increased in the nutrient solution. Applying NH4＋:NO3－=75:25 and 100:0 reduced net photosynthesis rate, stomatal conductance, and transpiration rate. Plants treated with NH4-N alone had the highest leaf phosphorus and the lowest leaf calcium concentrations. The concentrations of manganese and zinc in leaves increased as NH4-N ratio increased. When NH4-N ratio increased, the medium EC increased from 0.8 dS•m-1 to 3.1 dS•m-1, while medium pH decreased from 6.5 to 3.3.
In coir-based medium, plants grew better with NO3-N than NH4-N. When applying NH4-N, dolomite (9 g•L-1) should be added to coir-based medium to maintain the medium pH between 5.2 and 6.2 for better root growth. Plants with NH4-N required a supplementary 9 g•L-1 dolomite to coir-based medium to grow equally well with those with NO3-N.
Anthurium ‘Pink Champion’ had fewer new-grown leaves and flowers, and slender petioles and peduncles when grown under 80% shade (76 µmol•m-2•s-1 PPF) than 50% or 60% shade (178 and 129 µmol•m-2•s-1 PPF, respectively) in winter. The 80% shading resulted in decreased leaf and spathe width. Plants grew better under 50% to 60% shading and 50% than those under 80% shading with 25% or 100% treatments.
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