Propagation of Ocotea Usambarensis engl. using Various Methods in Mt. Kenya Forest, Nithi County, Kenya
Information on seed germination of trees is important as it forms a vital baseline for among other information on the germination of indigenous seedlings which take many years to germinate. The study was carried out to find out the effect of different light intensities and growth hormone on the propagation of Ocotea usambarensis Engl.The study was carried out for a period of three months (August to October 2010). The objective of the study was to determine the best propagation method using sexual and asexual parts of Ocotea usambarensis .Seed germinaton and sprouting of buds from various planted cuttings which had been collected from mature Ocotea trees in Chogoria forest was monitored. Some cuttings were first treated with azatone rooting hormone before planting. The collected planting materials were planted in a nursery and the parameters which were measured were the germination percentage, the number of sprouting buds at every ten days interval for 90 days under different light intensities, light intensity measurements using Photosynthetic Active Radiation meter, root collar diameter and height of wildlings from the tree over the same period and the shoot : root biomass taken after 90 days. Other materials for collecting data were measurement equipment like Vanier Calipers, rulers and weighing balances. Data analysis was done using GENSTAT computer soft ware. Analysis of variance (comparison of the means of the sprouting buds), percentages and shoot: root ratios were used to establish the best Camphor propagation materials and the best rooting and growth conditions. The results revealed that sprouting of buds was highest in treated sucker stem cuttings with a rooting hormone (mean number of sprouting buds=16.44, light intensity of 8220 Lux) while at 575 Lux site, mean number of buds sprouting was only 7.89. Untreated stem cuttings produced a mean of 7.0 buds at the same level of 8220 Lux lightt intensity. Mean number of sprouting buds from treated root sucker cuttings under light intensity of 8220 lux was observed to be 8.67, while buds from the treated branch cuttings exhibited a mean of only 1.33.Mean number of buds recorded from the treated Ocotea cuttings were relatively higher (62.99%), than those from the untreated cuttings (37.10% ) after 90 days of the experiment. Shoot: root biomass ratio was highest for the branch cuttings (0.5) compared to the stem and root cuttings (0.43 and 0.45 respectively). However the branch cuttings had the fewest number of sprouting buds. Germination percentage recorded in Ocotea seeds in the experiment was only 3 %. Investigation of growth performance of Ocotea wildlings under different light intensities indicated that the wildlings placed in partial light intensity site of 3960 lux exhibited a higher growth performance compared to the wildlings in the other sites. Conclusion is that treated stem and root cuttings in the open produced more buds than the other cuttings and the recommendation is that stem and root cuttings should be treated with a rooting hormone before planting and that they should not be covered in the nursery to achieve better performance.