Mini-cuttings technique: a new ex vitro method for clonal propagation of sweetgum

An efficient production system, which can quickly produce high quality plants, is shown in this study of Liquidambar styraciflua. The mini-cuttings technique was used for ex vitro clonal propagation of three sweetgum clones. The semi-hydroponics system for production of propagules was also tested, and the concentration of indole-3-butyric acid (IBA) for rooting was evaluated. Three adult clones, produced according to conventional cutting processes, were used as mini-stumps and maintained in semi-hydroponics systems of medium size sand. Ten collections of sprouts were prepared to evaluate the production of semi-hydroponics systems (mini-clonal hedges). Sprouts from collection number six were used at different concentrations of IBA solution (0; 500; 1,000; 3,000 and 6,000 mg l⁻¹) to test the mini-cuttings technique. The high survival rates of mini-stumps after ten collections (96.3%), and high annual production per square meter (~2,953 mini-cuttings) showed that the mini-clonal hedges are viable to conduct sweetgum mini-stumps. The formation of 62.5% of healthy plants after hardening under outdoor conditions showed that sweetgum could be successfully propagated by the mini-cuttings technique.