Rooting of late spring cuttings of Chinese fringetree (Chionanthus retusa Lindl.)

Two experiments, one using a conventional mist system the other a humidity chamber, were conducted using cuttings of Chinese fringetree (Chionanthus retusa Lindl. ). Cuttings were treated with either 0.0%, 0.1%, 0.3% or 0.8% concentrations of indole butyric acid. In the conventional mist system, weeks three and four showed significantly higher mean percent rooting and mean root quality ratings than weeks one, two and five. The most effective level of hormone used was 0.8%. The interaction of these effects showed an increase in the effectiveness of IBA through the third week followed by a gradual decline in effectiveness. In the humidity chamber experiment, weeks one and three showed significantly higher mean percent rooting and mean root quality ratings than weeks two, four, and five. The 0.8% concentration of IBA was the most effective hormone treatment used. The interaction of these effects showed an increase in IBA concentration increased percent rooting for all weeks. For this study, the ideal time to collect cuttings was late May to the latter part of June.