Rooting ability of Dorycnium spp. under different conditions

The rooting ability of cuttings of two species of Dorycnium (D. hirsutum L. and D. pentaphyllum Scop.) under different conditions was determined. The main variables examined were the source of the cutting (apical vs. medial), the temperature of the rooting environment (warm vs. cold greenhouse) and the auxin treatment (50 mg l(-1) IBA vs. 200 mg l(-1) IBA vs. untreated). The source of the cutting had no significant effect on the rooting ability of D. pentaphyllum. Rooting was stimulated under warm conditions (68.6% warm vs. 42.8% cold). Auxin application, irrespective of dose, also improved the rooting capacity of cuttings (70.4% IBA-treated vs. 26.2% untreated). The root number, longest root length and length of the rooting zone were also significantly increased by the warm environment and treatment with IBA. Highest rooting values for D. hirsutum were achieved with apical cuttings grown in the cold greenhouse. Treatment with IBA showed no effect on rooting in this species. (C) 1998 Elsevier Science B.V. All rights reserved.