Figures (5)  Tables (1)

    • Figure 1. 

      Photo of (a) semi-hardwood and (b) hardwood cutting blocks taken 14 weeks after the cuttings were struck.

    • Figure 2. 

      Photos of semi-hardwood (a) and hardwood (b) cuttings taken 14 weeks after the cuttings were struck.

    • Figure 3. 

      The survival rate (a), rooting percentage (b), and callus rate (c) of O. fragrans semi-hardwood and hardwood cuttings under various treatments after 14 weeks. Error bar = standard error (SE). Likelihood ratio tests were used to test the treatment effects, and different letters indicate significant differences at p ≤ 0.05 according to Tukey-adjusted estimated marginal means.

    • Figure 4. 

      (a) The number of roots per cutting, (b) total root length, (c) average root length, and (d) longest root of O. fragrans semi-hardwood and hardwood cuttings under various treatments after 14 weeks. Error bar = standard error. Likelihood ratio tests were used to test the treatments' effects, and different letters indicate significant differences at p ≤ 0.05 according to the Tukey-adjusted estimated marginal means.

    • Figure 5. 

      (a) The root index and (b) cutting biomass of O. fragrans semi-hardwood and hardwood cuttings under various treatments after 14 weeks. Error bar = standard errors. Likelihood ratio tests were used to test the treatments' effects, and different letters indicate significant differences at p ≤ 0.05 according to the Tukey-adjusted estimated marginal means.

    • Cutting type Parameter Unit $\chi^2 $ df p-Value
      Semi-hardwood Survival rate % 14.986 7 0.036*
      Rooting percentage % 18.976 7 0.008**
      Callus rate % 43.913 7 <0.001**
      Number of roots 117.95 7 <0.001***
      Total root length cm 22.952 7 0.002**
      Average root length cm 22.625 7 0.002**
      Longest root cm 21.787 7 0.003**
      Root index 23.824 7 0.001**
      Biomass g 25.468 7 <0.001***
      Hardwood Survival rate % N/A N/A N/A
      Rooting percentage % 23.537 7 0.002**
      Callus rate % 15.472 7 0.03*
      Number of roots 179.05 7 <0.001***
      Total root length cm 37.401 7 <0.001***
      Average root length cm 31.757 7 <0.001***
      Longest root cm 33.216 7 <0.001***
      Root index 41.76 7 <0.001***
      Biomass g 34.993 7 <0.001***
      * p ≤ 0.05; **, p ≤ 0.01; ***, p ≤ 0.001; NS, no significance; N/A, not applicable. Statistical tests were not performed for the survival rate of the hardwood batch as this had 100% survival across all treatments.

      Table 1. 

      GLMM results for survival rate (%), rooting percentage (%), callus rate (%), root number per cutting, total root length (cm), average root length (cm), longest root (cm), root index, and biomass (g) of semi-hardwood (Semi) and hardwood (Hard) cuttings as influenced by the IBA treatments.