عنوان مقاله [English]
Introduction: Miniature rose (Rosa hybrida) are well known as one of the world’s most popular ornamental plants cultivated worldwide as potted and/or bed plants. Nowadays, more than 100 million pots of miniature roses are propagated by stem cutting in the commercial greenhouses of European countries such as Denmark and Germany. Some treatments such as application of plant growth regulators and suitable rooting medium could be required for accelerating root formation in rose cuttings. Using plant growth regulators like natural or synthetic auxin is a pre-requirement for the initiation of adventitious root in some stem cuttings and it has been reported that the division of the first initiator cells of root depends on internal or synthetic auxin. Methods of application of these chemicals and suitable concentration could be related to several factors, importantly the plant varieties, type of cuttings and the time of cutting preparation. Various kinds of media such as soil, peat moss, perlite and vermiculite are used as bed substrate according to required ratio. Rooting media must provide appropriate moisture and air ventilation for cuttings establishment, which highly affect the cuttings root formation. Appropriate procedure for using wastes materials as culture bed, especially those materials that produced locally, is main aim of some studies to find an alternative medium in ornamental pot plant production. In this regards, evaluation of agricultural wastes to be used to culture bed and introducing suitable materials could be considered. Accordingly, the objective of the present study was to determine the effects of two types of plant growth regulators and bed combinations on rooting percentage of semi-hardwood cuttings in miniature rose.
Materials and Methods: In order to evaluate the effects of different concentrations of indolebutyric acid (IBA) and naphtaleneacetic acid (NAA), and two media with different composition on root formation of miniature rose stem cutting, this research was carried out as a factorial on the basis of randomized complete design (RCD) with three replications. Plant growth regulators including IBA at concentrations of 0, 1000, 2000 and 3000 mgl-1, concentrations of NAA at 0, 500, 1000, 1500 and 2000 mgl-1 were applied together with two types of rooting media. Media including mixing volume of perlite, tea waste compost and sand in a ratio of 1: 2: 2, and perlite, peat and sand in a ratio of 1:2:2 were mixed and applied in this experiment. Using SAS software, data was analyzed based on a generalized linear model (GLM) analysis and tested by least significant difference (LSD) at (P-value< 0.05).
Results and Discussion: Results showed that the highest rooting percentage of cuttings was obtained with 2000 mgl-1 of IBA, while no significant effect of NAA treatment and different rooting media on percentage of rooting was revealed. The two-fold and three-fold interaction of treatments on other measured traits such as primary and secondary root number and root diameter were significant. The two-fold interaction of NAA treatments and rooting media on the trait of primary root number were no significant. The highest root number and root diameter measured in medium containing perlite, tea waste compost and sand in a ratio of 1:2:2 for cutting received combined plant growth regulators.
Conclusions: Compost, the final product of organic residues degradation, improves soil physical characteristics such as soil aggregate formation and stability, water penetration, porosity, compressing resistance and nutrients availability. As well, it improves soil biological characteristics and in result, integration of compost with soil can increase growth, yield and quality of crop. There are also some evidences that in contrast of peat, compost contains plant growth regulators improved plant growth and development. Totally, considering our obtained results, in order to accelerate rooting formation in miniature rose cuttings, treatment of cuttings with synthetic plant growth regulators in medium containing perlite: tea wastes compost: sand (2:2:1) under alternate mist system is recommended. Organic materials activate root area as well as improving fertility of soil. They also play a role in supplying and releasing absorbable nutrients, root establishment, enhancing field capacity, reducing evaporation from soil surface and reducing expenses. Therefore, we emphasize on appropriate using of these components in order to obtain better productivity.