Effects of donor tree age, cutting collection time and K-IBA application on rooting ability of Taxus baccata L. stem cuttings: preliminary results

The present study investigates the effect of donor tree age (juvenile, adult), collection time (March, November) and the K-IBA (indole-3-butyric acid potassium salt; 0, 3, 6, 12 g L⁻¹ K-IBA) application on rooting of T. baccata stem cuttings. Terminal hardwood leaf stem cuttings were collected of the year 2013 from individuals growing in their natural habitat in the Cholomontas mountains in the northern part of Greece. In cuttings taken from adult individuals, the application of K-IBA only significantly improved the rooting percentage. However, in cuttings taken from juvenile individuals, the collection time and K-IBA application as well as their interaction were statistically significant. In November collection, the cuttings treated with 12 g L⁻¹ of K-IBA exhibited the highest rooting percentage (98.3%), while in March collection, the cuttings treated with 3 g L⁻¹ of K-IBA exhibited higher rooting percentages (61.7%) than those of control (41.7%). In cuttings taken from juvenile individuals, the K-IBA application significantly improved the rooting of cuttings collected in November compared with those collected in March. The cuttings taken from juvenile individuals, exhibited significantly higher rooting percentages than those taken from adult individuals.