Rooting Response of Thuja occidentalis L. to Different Soilless Media and Stem Propagation Techniques in Ghana

Abstract

Aims: Studies were carried out to ascertain a suitable soilless medium which would enhance root development in Thuja occidentalis using stem cuttings and air-layered propagules. Economically, the demand for these ornamentals necessitates that the difficult-to-root phenomenon should be solved. Study Design:  A 2 x 6 factorial in a randomised complete block design replicated three times was the experimental design used for the stem cutting experiment. While a complete randomised design with 6 treatments which were replicated three times used for the air-layering experiment. Place and Duration of Study: Department of Horticulture, KNUST, Ghana, between June 2009 and August, 2009. Methodology: In the stem cutting propagation experiment, six media types; 100% topsoil, 100% palm-mix, a mix of 50% teak sawdust and 50% coconut coir, a mix of 50% palm-mix and 50% coconut coir, a mix of 50% palm-mix and 50% teak sawdust and a mix of 50% palm-mix, 25% teak sawdust and 25% coconut coir and two stem cuttings being straight and heel stems giving twelve (12) treatment combinations was used and replicated three (3) times. For the air-layering experiment, air-layers were made on the selected branches of the plant. Different media were colour-tagged. Results: Results from the study showed that, a mix of 50% teak sawdust and 50% coconut coir was the most suitable soilless medium, with regards to its physico-chemical properties, and promoted the highest number of rooting. With respect to the root length, the mix of 50% palm-mix and 50% coconut coir recorded the longest root. The best soilless medium that promoted rooting in the air-layered propagule was a mix of 50% palm-mix and 50% teak sawdust. Conclusion: Thus for propagation works in Ghana, the 50% teak sawdust+50% coconut coir and 50% palmix + 50% coconut coir and their variations be experimented on other difficult-to-root ornamental plants to validate its use as the best soilless medium for most difficult-to-root ornamental plants.