Improvement of microplant establishment through in vitro and ex vitro exogenous chemical applications

Effects of exogenous applications of ethanol, glycinebetaine and paclobutrazol on rooting and weaning of apple microcuttings were studied. Dipping of microcuttings in paclobutrazol solution during the in vitro rooting resulted in good acclimatisation of the microcuttings, but shoot growth was reduced by 1/3 in comparison with the control plants. Foliar application of ethanol had no positive effects. Eight weeks following the foliar application of 0.1 M, 0.2 M and 0.3 M glycinebetaine onto newly transplanted plantlets, shoot growth had increased by 30-76 % in comparison with the non-treated control plants. Higher, 0.5 M concentration, was detrimental to the plants. Glycinebetaine treatment was easy to include in the acclimatisation process of apple microcuttings. The effect of one application lasted at least for 8 weeks.