Cluj-Napoca Effect of Timing on Callus Formation and Rooting Ability in IBA-Treated Hardwood Stem Cuttings of Persian Walnut, Hazelnut and Apple

Promotion of callus formation and rooting in hardwood stem cuttings of Persian walnut (Juglans regia L.), hazelnut (C. maxima) and apple Malus pumila) were evaluated by taking cuttings every two weeks from December 2001 through November 2002. Cuttings were treated with 4-indol-3-butyric acid (IBA) at 3000 ppm for 6 s, placed in a greenhouse under intermittent mist, and evaluated after 8 weeks. There were three replications of each species and sampling date. The results showed that the rooting of cuttings was zero in late spring, summer, and early autumn, whereas there was a significant increase in percentage rooting, with rapid and complete callus formation in late autumn, winter, and early spring. For example, in December, callus formation and rooting percentages were: Persian walnut (80 and 6%), hazelnut (49 and 36%), and Apple (43 and 31.5%), respectively