Effects of pretreatment of mother plants with BA and concentration of IBA on rooting of Leucospermum 'Succession II' stem cuttings

摘要

In order to increase the plant material necessary for the vegetative propagation of Leucospermum 'Succession II', plants of this cultivar were pretreated in July with benzyladenine (BA) to stimulate the production of axillary shoots for the preparation of cuttings, which were used in October to carry out an experiment in which the treatments resulted from the combination of two types of pretreatment (100 and 200 ppm of BA) and four concentrations of IBA (0, 500, 1000 and 1500 ppm of IBA). A randomized block design with 2×4 treatments (10 cuttings per treatment) and four replications was used. The total number of cuttings was 320. Cuttings were removed of leaves on their basal half, and the bases were treated with indolebutyric acid (IBA) in a solution of 50 ethanol to give treatments of 0 (control), 500, 1000 and 1500 ppm using the quick-dip method (5 s), followed by a dip in talc containing benomyl and captan, both at 5 of active materia concentration Then they were planted in a mixture of polystyrene foam pellets and peat moss (6:4 v/v ratio) in plastic propagating trays, which were placed on a bed with bottom heat (22±2°C) in a well-ventilated greenhouse. Irrigation was supplied by microjets from 15 to 40 s, according to the weather, every 30 min from 9:00 to 17:00 h. At 16 weeks, 70 of transplantable cuttings were obtained in treatment 4 (100 ppm BA + 1500 ppm IBA), followed by treatment 2 (100 ppm BA + 500 ppm IBA) (52.5). At the end of the trial, at 22 weeks, the situation was similar, with treatment 4 presenting the highest percentage of transplantable cuttings (82.5), followed by treatments 2 (65). Pretreatment with BA and treatment with IBA had a significant effect on rooting. The interaction BA × IBA was not significant.