Influence of cutting position, wounding and IBA on the rooting of Leucadendron discolor stem cuttings

Leucadendron discolor was introduced in Tenerife in 1988 by the cooperative Florican. Rooted cuttings were imported from Israel and a small plantation was set in Los Rodeos (La Laguna) at 600 m.a.s.l. The attempts to propagate L. discolor by stem cuttings using the standard technique in the Florican nursery proved to present some difficulties, with rooting percentage not satisfactory from the commercial point of view (about 50%). With the purpose of observing if the basal wounding technique (two shallow and opposite incisions) combined with different IBA concentrations, could improve the results of the rooting process, an experiment was carried out in which terminal and basal cuttings were rooted in winter-spring with bottom heat (25 +/- 2 degrees C) and microjet irrigation. A randomized block design was used with five treatments and four replications. The number of cuttings for each treatment was 10. The total number of cuttings was 200. The treatments used were the following: A) wounded terminal cuttings treated with 4000 ppm of IBA; B and D) wounded and no wounded basal cuttings treated with 2000 ppm of IBA, respectively; C and E) wounded and non wounded basal cuttings treated with 4000 ppm of IBA, respectively. At the end of the trial (20 weeks) treatment A showed. the higher percentage of transplantable cuttings (85%), followed by treatments C (52.5%), B (25%), E (15%) and D (5%). The rooting process was much faster and the cuttings developed a more vigorous root system in treatment A, which was significantly different from the other four treatments. In wounded cuttings two ranks of callus nodules appeared along the edges of each incision. Roots emerged associated with the ranks of callus nodules.