Effect of Cutting Type, Indol-3-Butyric Acid and the Growing Season on Rooting of Stem Cuttings of Rosa hybrida Cv Eiffel Tower

A field experiment was conducted for two successive years to investigate the conventional propagation of Rosa hybrida cv.Eiffel Tower using stem cuttings as affected by the growing season of the year, cutting type and the application of indol-3-butyric acid(IBA) at different concentrations.  Uniform cutting types ~ 15-20 cm long (apical, median and basal) were collected from the current year growth of healthy mother plants. Then the cutting bases (2-3 cm) were soaked for 20 minutes in different concentrations of IBA (0, 500, 1000 and 1500 ppm) and the lower end of the cuttings were stuck into 14-cm plastic pots filled with a peat: perlite mixture (1:1v/v). The obtained results statistically analyzed by ANOVA showed that rooting percentage of stem cuttings, number of roots and root length varied according to cutting type, concentration of IBA and growing season. The median cutting type was significantly superior to the other types in both autumn and spring seasons. IBA application significantly improved rooting percentage, root number and root length of the treated cuttings comparing to the untreated ones (control). A significant interaction between cutting type and IBA concentrations was observed on most of the characteristics measured  during the autumn season only.