Rooting of African mahogany (Khaya senegalensis A. Juss.) leafy stem cuttings under different concentrations of indole-3-butyric acid

摘要

Vegetative propagation were studied in order to implement Khaya senegalensis A. Juss. wood production, conservation and genetic improvement programs. The objective of this research work was to establish the requirement as well the appropriated concentration of indolbutiric acid (IBA) in the K. senegalensis leafy stem cuttings to produce new plants. The basal end of the leafy stem cuttings were immersed, at first subjected to the so called slow method, in a 5% ethanol solution with 0, 100, 200 and 400 mg L-1 of IBA for 12 h and, as another procedure, the so called quick method, to a 50% ethanol solution with 0, 3000, 6000, 9000 and 12000 mg L-1 of IBA for 5. The leafy stem cuttings were transferred to plastic trays filled with 9.5 L of medium texture expanded vermiculite in which the cuttings had their basal end immersed to a depth of 3 cm in an 8.0 x 8.0 cm spacing. The experimental units were distributed according to a completely random design with five replications. Each experimental unit consisted of twelve cuttings. The experiment was conducted in a greenhouse under a 50% of shade condition during the period from January to June of 2012. The quick method, in comparison with the slow one, gave the best results in terms of percentage of rooted stem cuttings and height of the sprouted plantlets. In the quick method, no differences between IBA concentrations were observed. The slow and the quick methods did not differ as to stem cuttings survival, total root length per leafy stem cutting, number of roots per stem cutting, plantlets survival and percentage of sprouted plantlets. It was concluded that K. senegalensis may be propagated by leafy stem cuttings taken from plantlets of seminal origin without the use of IBA.