EFFECT OF GROWING MEDIA ON YIELD AND QUALITY OF SOILLESS CULTIVATED ROSE

A two-year trial of open-cycle soilless cultivation of four varieties of rose was conducted in Bagheria (Sicily, Italy), in an unheated greenhouse with metal structure and polyethylene cover, with the aim of evaluating the influence of two growing media on quantitative and qualitative parameters of cut flower production. Plants of the cv. Anastasia, Fenice, New Fashion and Gold Strike were grown in plastic bags filled with perlite, pure or mixed with coconut coir dust (1:1, v/v). Growing media affected yield and quality: perlite/coir dust caused the highest amount of flowers (17.7 stems/plant) and the longest stems (65 cm). Significant differences were also recorded among varieties: cv. Anastasia produced the highest number of stems (18.7 per plant) and the longest buds (5.8 cm); cv. Fenice provided flowers with the maximum average length (70 cm); cv. New Fashion gave the highest amount of leaves/stem (55.8). Substrates also differed in water consumption (0.78 and 0.62 L/plant/day for plants in perlite and in perlite/coir, respectively) and available mineral elements, with a lower availability of nutrients for the plants grown in the inert media. The best results in the mixture are probably related to the higher water holding capacity and cation exchange capacity of coconut dust, proving this organic material as one of the main alternatives to peat for hydroponic culture.