The popularity of the nobile-type dendrobium (Dendrobium nobile hybrids) has been increasing globally. More information regarding the effects of long-distance shipping, from producing countries to destination market countries, on the post-shipping plant performance is needed. In this study, two nobile-type dendrobium cultivars were subjected to simulated dark shipping (SDS) at various temperatures and durations. Changes in net CO2 uptake rate (Pn), chlorophyll fluorescence, and leaf relative water content after plants had been treated with SDS were investigated. Furthermore, shipped plants were vernalized to investigate the effect of dark shipping on the subsequent flowering quality. Dark shipping for 7 days at 15 °C did not affect the post-shipping photosynthetic performance of D. Lan Tarn Beauty. Increasing the shipping duration from 7 to 21 days increased the time required for Pn recovery from 1 to 12 days. Dendrobium Lan Tarn Beauty recovered its Pn within 4 days when shipped for 21 days at 10 °C, and this was prolonged to 11 days when the plants were shipped at 20 °C. Changes in Fv/Fm indicated that there was no marked damage to either cultivars, and the leaf relative water content was little affected by SDS. Dendrobium Lan Tarn Beauty and D. Lucky Girl shipped at 10 °C flowered 5 and 8 days earlier, respectively, compared with unshipped plants. Regardless of the shipping conditions, shipped D. Lucky Girl had a lower flower diameter and higher total flower count than unshipped plants. No differences were found in the number of nodes with flowers or the total flower count between shipped and unshipped D. Lan Tarn Beauty. Our study suggested that dark shipping for up to 21 days is possible for nobile-type dendrobiums. We recommend shipping temperatures of 10 to 15 °C to reduce the detrimental effects caused by long-term dark shipping.
Ariningsun P. Cinantya, Fure-Chyi Chen, and Yao-Chien Alex Chang
Huan-Ying Yao, Ren-Shih Chung, Sheng-Bin Ho, and Yao-Chien Alex Chang
Sphagnum moss, which has very different chemical and physical characteristics compared with other soilless media, is commonly used as a substrate to grow Phalaenopsis in countries such as Japan and Taiwan. Pour-through (PT) is a nondestructive, effective, and convenient medium extraction method developed for peat-based media. To know if PT can be applied to sphagnum moss and to set up a standard procedure, experiments were conducted to test the effects of volume and electrical conductivity (EC) of the displacing solution and the timing of leachate collection on leachate properties. Results demonstrated that applying distilled water with a volume less than 70 mL to 10.5-cm pots 1 h after fertigation did not influence leachate EC and pH. Applying displacing solution with EC between 0.001 and 0.93 dS·m−1 1 h after fertigation did not affect leachate EC or pH. Thus, in theory, a variety of solutions may be used for displacement. Leachate properties were found to remain consistent when collected between 20 and 160 min after fertigation. These results demonstrated that PT can be successfully used in Phalaenopsis cultivation with sphagnum moss. Furthermore, substrate EC obtained by PT extraction was highly correlated with that by the press method, confirming that PT is a feasible medium extraction method for sphagnum moss in Phalaenopsis cultivation.
Jiunn-Yan Hou, Wei-Li Lin, Nean Lee, and Yao-Chien Alex Chang
Phalaenopsis flowers are prone to wilting under ethylene (C2H4) stress. 1-Methylcyclopropene (1-MCP) can protect Phalaenopsis flowers against ethylene injury. In this study, we determined the residual effect of 1-MCP and how it is affected by temperature. The efficacy of multiple applications of 1-MCP was also investigated. The residual effect of 1-MCP was determined by pretreating blooming Phalaenopsis amabilis plants with 0.8 μL·L−1 1-MCP for 8 hours on Day 0 followed by 2 μL·L−1 ethylene fumigation for 12 hours on designated days. Without 1-MCP pretreatment, flowers began to wilt within 2 days after exposure to ethylene. Duration of the residual protection of 1-MCP on P. amabilis was ≈6 to 8 days during summer in Taiwan. Lower temperatures after 1-MCP application prolonged protection times. The full protection times under day/night temperatures of 25/20, 20/15, and 15/13 °C were 4 to 8, 10 to 13, and 13 to 17 days, respectively. Furthermore, multiple applications of 1-MCP extended the duration of 1-MCP protection against ethylene. Three applications increased the residual protection of P. amabilis by 1-MCP to at least 24 days.
Hadi Susilo, Ying-Chun Peng, Shui-Cheng Lee, Yu-Chun Chen, and Yao-Chien Alex Chang
Phalaenopsis is currently the world’s number one potted flower crop. It is a slow-growing plant that responds slowly to nitrogen (N) fertilization and is noted for great resilience against N deficiency. Despite the great significance of N during the cultivation of Phalaenopsis, little has been studied on the uptake and partitioning of N in this crop. The stable isotope 15N was used as a tracer to investigate the uptake and partitioning of N and the roles of organs in sink and source relationship of N partitioning during different stages in Phalaenopsis. Fertilizer labeled with 15N was applied to Phalaenopsis Sogo Yukidian ‘V3’ during the vegetative growth stage on different parts of plants. Both leaves and roots were able to take up N. Nitrogen uptake efficiency of young roots was the highest, followed by old roots, whereas that of leaves was lowest. No difference of N uptake efficiency was found between the upper and lower leaf surfaces. Movement of fertilizer N to the leaves occurred as early as 0.5 day after fertilizer application to the roots. The partitioning of N depended on organ sink strength. During the vegetative growth stage, newly grown leaves and newly formed roots were major sinks. Sink strength of leaves decreased with the increase in leaf age. Stalks and flowers were major sinks during the reproductive growth stage. Mature leaves were a major location where N was stored and could serve as a N source during the reproductive growth stage and also for new leaf growth.