Abstract
The effects of using media hardened by heat fusion of polyester fibers on yields and quality of cut flower stems ‘Asami·Red’ (syn. ‘Rote Rose’) rose and on the composition of nutrient solutions for a year under closed hydroponic culture were investigated. The yields of cut flower stems grown in vermiculite medium (grain diameter: 6–7 mm) and coconut coir medium (fiber length: 3 mm) were remarkably higher than those grown in rockwool and perlite medium (grain diameter: 0.6–1.5 mm or 2.5 mm). The weight of a cut flower stem did not differ among the media, however stem lengths from both grain perlite media were shorter than those from other media. Eighteen months after transplanting, the length and width of each medium were the same as those just after planting, and the thickness in rockwool and coconut coir media decreased slightly. The solidity of each medium remained almost the same at the termination of the project. The pH of the nutrient solution in the rockwool medium changed the most, becoming higher than that of the other media for most of the time. The EC in coconut coir medium tended to be high throughout the project. The concentration of NH4-N decreased, while other inorganic components increased gradually. In conclusion, the vermiculite or coconut coir media hardened by heat fusion of polyester fibers is the most favorable of alternative media tested in comparisons with rockwool medium under closed hydroponic culture.
