| Robinia pseudoacacia (locust hereafter) is an ornamental tree with various uses. Both homologous tetraploid (tetraploid hereafter) and diploid cultivars are commercially available. The tetraploids have advantageous traits, but poor germinability, and cuttings are difficult to root. Since auxin applications can promote rooting, we evaluated the effects of dipping cuttings in various indole-3-butyric acid (IBA) concentrations for four hours on rooting parameters. IBA significantly affected all measured parameters of both tetraploid and diploids cuttings. Tetraploid cuttings produced no roots without IBA. The effects were strongest at 1000 and 800 mg/L IBA for tetraploids and diploids, respectively. Values for tetraploids and diploids respectively, were (1)... |
