Clonal Propagation of Melia Volkensii (Gűrke) Trees for Seed Orchard Establishment in Kiambeere, Embu County, Kenya
Kajuju, Nturibi Carol
MetadataShow full item record
Melia volkensii (Melia) is an indigenous tree species belonging to the plant family Meliaceae. In Kenya, the tree is commonly known as “Mukau”. Melia grows naturally in the arid and semi-arid zone of Tanzania, Ethiopia, Somalia, and Kenya. It’s highly valued for its timber which is termite resistant and so imperatively durable. Despite its popularity, its domestication efforts have been minimal, as a result of poor access to quality planting material and lack of a comprehensive viable propagation protocol. Seed propagation has been hectic due to difficulties in extraction, poor germination and high post-germination mortality which has hindered its wide scale cultivation. The study therefore sought to investigate the potential of establishing Melia volkensii seed orchards by use of high quality vegetatively propagated seedlings in Kiambeere, Kenya. The hormone Indole-3- Butyric Acid (IBA) at various concentrations (0.25 %, 0.5 % and 0%) was used to determine the effect on rooting and shooting of cuttings of different lengths, diameters and positions (top, bottom and full). The effect of merchantable heights on the production of ideal cuttings was also investigated. A complete block design of five blocks (IBA concentration, cutting diameter, cutting length, cutting section and cutting portions) was used. Cuttings were obtained from selected healthy plus trees from fields and raised in non mist propagators where number of roots and shoots that sprouted were observed and recorded. The data was analysed for significance by use of GENSTAT version 14 computer software, where significant treatments were separated by Least Significant Difference at p=0.05. Results showed significant improvements in shooting and rooting percentage both of stem and root sections (p<0.001) with 0.25 % IBA concentration having highest grand rooting percentage of 15.19 %, and root sections developing more morphologically than stem sections in all IBA concentrations. Diameter of cuttings also significantly affected rooting (p= 0.031), with smaller diameter (diameter of ≤ 0.5 cm) exhibiting more rooting potentials than wider cuttings ≥0.5cm. Cutting lengths of ≤ 12 cm had a higher rooting ability than long ones of ≥12 cm. Portions obtained from basal points (bottom portions) gave the best rooting percentages compared to those from apical points of cuttings (top portions). Moreover, donor/plus trees with merchantable heights of 2 - 5 m provided the best cuttings which gave the best rooting (17.5 %), thus proving to be the ideal height from which planting material need to be harvested. The research therefore recommends that propagation programmes utilize cuttings of short lengths ≤ 12 cm, with diameters below 0.5cm from basal points harvested from maintained Melia plus trees of merchantable heights of 2 - 5 m while establishing future seed orchards.