STIMULATION OF ROOT INITIATION IN HARDWOOD SWEET AND SOUR CHERRY ROOTSTOCKS (Prunus mahaleb L.)

Summary. Comparative studies were conducted for the purpose of assessing the rooting of four mahaleb species hardwood rootstock cuttings (SL-64, P-1, IK-M9 and T-36). In case no growth regulators were applied only callus or single rootlets were observed. Indole-3-butyric acid in concentration of 2 g/l greately stimulated root initiation which was considerably higher in IK-M9 and T-36 cuttings than in the SL-64 rootstock. Single application of vitamin K 3 caused a slight induction of root initiation (10–15%) in the SL-64 rootstock. A pronounced synergistic effect was found after combined treatment with indole-3-butyric acid and vitamin K 3 , root initiation in the hardwood cuttings reaching up to 93%.