Studies On Growing Media Used In Phalaenopsis Production

The physical and chemical properties of sphagnum moss, composted bark, coconut chunks and sphagnum peat were studied; in addition, the physical and chemical properties of bark mixed with sphagnum peat by different ratio and coconut chunks mixed with sphagnum peat by different ratio were also studied. In order to test the feasibility of these mixed media used in Phalaenopsis production, a study was conducted to access the effect of mixed media on growth of Phalaenopsis. A series of studies indicate that:1. The water-filled porosity in sphagnum moss was 60.2%, and it was 52.6% in sphagnum peat, the water-filled porosity in sphagnum moss and sphagnum peat were both significant higher than that in bark or coconut chunks. Cation exchange capacity (CEC) in sphagnum moss and sphagnum peat were higher than that in bark or coconut chunks, which indicated that sphagnum moss retained too much water and mineral nutrients when used in Phalaenopsis production. Accordingly, bark and coconut chunks retained less water and mineral nutrients. The air-filled porosity in bark was 53.6%, and it was the highest among the four media concerned in this study. The second is coconut chunks. They were both significant higher than that in sphagnum moss and sphagnum peat, which suggests that bark and coconut chunks have favorable air capacity.2. By adding 10-50% proportion (by volume) of sphagnum peat to bark, the value of water-filled porosity can be elevated by 4.6-13.0 percent, but still significant lower than that in sphagnum moss. When the proportion of sphagnum peat was 10-40%, the ratio of W/A (water-filled porosity/ air-filled porosity) in bark-peat media was significant higher than that in sphagnum moss. While the proportion of sphagnum peat rised to 50%, this ratio was lower than it in sphagnum moss, but not significantly. The pH of bark-peat media was5.67-6.16, EC was 0.12-0.19.3. By adding 10-50% proportion (by volume) of sphagnum peat moss to coconut chunks, the value of water-filled porosity can be elevated by 3.1-12.7 percent, but still significant lower than that in sphagnum moss. When the proportion of sphagnum peat was 10-50%, the ratio of W/A in bark-peat media was significant higher than that in sphagnum moss. The pH of coconut chunks -peat media was 5.73-6.23, and EC was 0.31-0.44.4. There were significant difference in dry weight and growing rate in different media. Plants grown in a mixture of 70 bark with 30 sphagnum peat or a mixture of 70 bark with 30 cutted sphagnum moss attained higher growth rate and produced more plant volume, fresh weight and dry weight than those in sphagnum moss or other media. Plants grown in a mixture of 50 coconut chunks with 50 sphagnum peat were similar with those in sphagnum moss.5. Based on an overall consideration of plante growth, environmental factor and costs, a principal media of 70 bark with 30 peatmoss (volume) was recommended to use in Phalaenopsis production. The next media recommended is a mixture of 50 coconut chunks with 50 peatmoss. The cost of media can be reduced 86% when these two mixed media were used in Phalaenopsis mass production.