| Abstrakt: |
This study explored the effects of indole butyric acid treatment on the vegetative propagation (cuttings) of Leyland cypress at different rates and periods in two experiments. Cutting materials were obtained from mother trees growing in the nursery. The low treatment rates included 25, 50, 100, and 200 ppm indole butyric acid, whereas the high treatment rates were 500, 1000, 2000, 4000, and 8000 ppm. The cuttings were treated with indole butyric acid for 24 and 48 hours for the low rates in the first experiment and 5 and 10 seconds for the high rates in the second experiment. The study was repeated three times, with 30 cuttings used in each repetition. Low-rate and high-rate treatments involved 900 and 1080 cuttings, respectively. The pretreated cuttings were then propagated in the greenhouse containing a mixture of peat (60%), perlite (20%), and sand (20%). In the low-rate experiment, there was a significant main effect for treatment rate and period as well as an interaction effect (rate × period). Indole butyric acid made no significant rooting difference at the higher rates. In the experiment with the high-rate of hormone, there was a significant main effect for treatment rate whereas the exposure period main and the rate × period interaction effects were not significant. The experiment with > 2000 ppm of hormone rates provided no additional significant increases in rooting and even depressed. In conclusion, 2000 ppm indole butyric acid pretreatment for 5 seconds with the greatest rooting rate of 77.6% is recommended for enhancing the rooting of leyland cypress hardwood cuttings. [ABSTRACT FROM AUTHOR] |
