2018 ASHS Annual Conference

Mississippi State University has developed several new crape myrtle selections, including Neshoba™. Objective was to determine optimal hormone source and concentration for hardwood cutting propagation of Neshoba™. Medial cuttings (12.7 cm) were harvested and stuck to a depth of 2.6 cm on 1 Feb. 2017. Medium was 100% perlite in 7.6 cm containers. Treatments included two basal treatments (wounded or non-wounded), three hormone mixtures (Hortus IBA, Dip & Gro, or Hortus IBA + NAA), and three levels of hormone (0, 1000, or 5000 ppm IBA). Experimental design was a RBCD with five single plant replications. Data collected included percent rooting, new shoot growth, cutting quality, root number, average root length (length of three longest roots/three), and root quality. Cuttings dipped in Hortus IBA 5000 ppm, regardless of basal treatment, had more roots compared to controls, or non-wounded Dip’N Grow 1000 ppm. Non-wounded cuttings dipped in Hortus IBA 1000 ppm had higher root quality compared to all cuttings except those wounded and dipped in Hortus IBA 5000 pm or non-wounded and dipped in Dip’N Grow 5000 ppm. Cutting quality was greater for wounded cuttings dipped in Hortus IBA 5000 ppm compared to wounded control, non-wounded and dipped in Dip’N Grow 1000 ppm, wounded and dipped in Dip’N Grow 5000 ppm, or non-wounded and dipped in Hortus IBA 5000 ppm + KNAA 2500 ppm. Growth was greater for cuttings that were wounded and dipped in Hortus IBA 5000 ppm compared to controls or cuttings dipped in Dip’N Grow 5000 ppm, non-wounded and dipped in Hortus IBA 1000 ppm + KNAA 500 ppm, or non-wounded and dipped in Hortus IBA 5000 ppm + KNAA 2500 ppm. When direct comparisons were made, wounding, increasing concentrations of Dip’N Grow or Hortus IBA + KNAA had no influence on measured characteristics. Cuttings treated with hormone had more roots compared to controls, but increasing hormone concentration only resulted in additional roots for cuttings dipped in Hortus IBA. Cuttings dipped in Hortus IBA had higher root and cutting quality ratings compared to controls, those dipped in Dip’N Grow, or Hortus IBA + KNAA. Cuttings dipped in Hortus IBA had greater growth compared to controls or cuttings dipped in Hortus IBA + KNAA. Results suggest hardwood cuttings of Neshoba™ crape myrtle may be successfully rooted without wounding or use of auxin, but use of Hortus IBA did improve cutting quality and growth.