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Coir is used around the world as a cultivation medium for plants; its commercial popularity is the result of its availability, low cost, and environmentally friendly characteristics. It is used as a medium in the hydroponic cultivation of Anthurium (Anthurium andraeanum Lind.) in Taiwan and is a new source for cut flower production around the world. Little is known about the nutrient requirements of Anthurium cultivated in coir under fluctuating climatic conditions. The objective of this study was to evaluate the influences of various nitrogen (N) concentrations on the growth and nutrient uptake of Anthurium cultivated in coir under different seasonal conditions. Four levels of N concentration in nutrient solution were used: 79 mg·L⁻¹ (NS79 treatment), 105 mg·L⁻¹ (NS105 treatment), 158 mg·L⁻¹ (NS158 treatment), and 210 mg·L⁻¹ (NS210 treatment) with NS105 serving as the control. The effects of N concentration and seasonal fluctuations on Anthurium were measured in dry weight, leaf growth, flower growth, and nutrient uptake at different growth stages during the 2-year study period. The results show that the dry weight, leaf area, and flower number were higher in plants receiving NS105 and NS158 treatments than those receiving NS79 and NS210 treatments. However, the NS158-treated plants produced better quality cut flowers than the NS105-treated plants in the first year of cultivation as indicated by their wider, circular spathe. Retarded growth of NS79-treated Anthurium was the product of insufficient N supply and reduced carbon (C) assimilation. The excess supply of N in the NS210 treatment resulted in small potassium (K) and magnesium (Mg) uptakes, which in turn resulted in poor growth in the second year of cultivation. However, the nutrient supplies in the NS158 and NS210 treatments yielded better Anthurium growth during the initial stage than the NS79- or NS105-treated groups. Regardless of plant growth, flower yield, and nutrient uptake, there were significant interactions between N treatments and seasonal fluctuations in subtropical conditions during year-round cultivation. We concluded that the limiting factor in Anthurium growth and yield during the spring and summer is the N supply, whereas climate conditions are the limiting factor during the fall and winter.

A simple and nondestructive technique, based on the line intersect principle, was developed for estimating simultaneously more traits of the newly grown roots of potted Phalaenopsis plants. Two kinds of root distribution counting pot (RDCP) were used in the present study, namely, RDCP with a large drawing grid (RDCPL) and RDCP with a small drawing grid (RDCPS). Fifty Phalaenopsis plants were randomly sampled during the cultivation period of two to eight months after transplantation for each kind of pots. The grid number of the newly grown roots of each plant was determined by both RDCPS and RDCPL, followed by measurement of other traits such as number, fresh weight, dry weight, and length of the roots. Data were subjected to regression analyses for the selection of predictive equations. The results revealed that the grid number determined by RDCPS correlated better with the traits of the newly grown roots of potted Phalaenopsis [coefficients of determination R ² = 0.71 to 0.90; low mean squared error (MSE)] than the grid number obtained with RDCPL (R ² = 0.66 to 0.83; high MSE). Without tedious and time-consuming measurements, the four linear equations obtained with RDCPS can be a simple and nondestructive estimation for predicting the number, fresh weight, dry weight, and length of the developing roots of Phalaenopsis plants grown in pots. Another 48 Phalaenopsis plants were randomly sampled during the cultivation period of two to eight months after transplantation for the validation of selected predictive equations. The accuracy of the predictive equations of the traits of newly grown roots obtained with RDCPS was different in the following order: length > dry weight > fresh weight > number.

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.