The effect of rooting medium, cutting type and auxin (IBA) treatment on propagation of Arizona cypress (Cupressus arizonica var. glabra)

In silver cypress (Cupressus arizonica), rooting of cuttings is not easily possible. To optimize the rooting properties of cuttings of this plant, a factorial experiment was conducted as multi-factor, based on a completely randomized block design with 4 replications and 4 cuttings in each replicate. In this study, four different types of cuttings (consisting of above-terminal, above-basal, below-terminal and below-basal), each 15 cm long, were taken from distal and proximal parts of a 15-year old silver cypress tree. Cuttings were treated with different concentrations of indole butyric acid (IBA) (2000, 3000, 4000 and 5000 mg/L) and were grown in different rooting media (pure peat, peat+ perlite (v/v), leaf compost and fine sand). Results showed that applied treatments had significant effect (P≥0.01) on rooting percent and callus formation, root length and number of roots. Most of the cuttings were decayed on leaf compost medium. The lowest level of rooting, root length and number of roots were obtained with below-terminal and then above-terminal cuttings in the fine sand medium. Cuttings were harvested after 6 months and rooting percent, callus formation, root length and number of roots were assessed. The highest rooting percentage, root length and number of roots were achieved from below-basal cuttings in peat+perlite medium treated with 3000 mg/L IBA