Sodium Cellulose Glycolate as a Thickening Agent for Liquid Auxin Formulations can Enhance Rooting of Stem Cuttings

Abstract

Abstract Stem cuttings of Abelia ‘Edward Goucher’, Buxus sinica var. insularis ‘Wintergreen’, Hedera helix, Hibiscus syriacus ‘Collie Mullens’, Ilex vomitoria ‘Nana’, Juniperus conferta ‘Blue Pacific’, and Rosa ‘Red Cascade’ received a basal quick-dip in solutions of Dip ‘N Grow at concentrations of 0 + 0, 50 + 25, 250 + 125, 500 + 250, 750 + 375, and 1000 + 500 ppm IBA + NAA prepared with and without 13.5 g/liter sodium cellulose glycolate (SCG) as a thickening agent. Cuttings of Ilex vomitoria ‘Nana’ exhibited increased rooting with increasing auxin concentration with inclusion of SCG. The other six taxa exhibited similar rooting percentages among all treatments, but exhibited an increase in root number and/or total root length with inclusion of SCG. Initial shoot growth on rooted cuttings of Abelia ‘Edward Goucher’ showed some reduction with increasing auxin concentration with inclusion of SCG, suggesting cuttings absorbed more auxin from solutions containing SCG owing to their extended period of exposure to the auxin. Otherwise, there were no negative responses to solutions containing SCG. The greater viscosity of solutions prepared with SCG can help reduce the possibility of spillage and evaporation of alcohol during use of the auxin solutions.