Presently, mass vegetative propagation of Eucalyptus is carried out by mini-cuttings, under controlled conditions. Despite the advances of this technique, there is no criterion to determine the optimum age of the cuttings for planting, which can reflect negatively on the quality, mainly on the root system, and consequently losses may occur in the field. Hence, in the present work was established a technical criteria based on the growth speed curves and intercrossing of daily current increasing curves and daily average increasing for the variables height, root, stem and shoot biomass. Due to the restriction of exploitable volume by the root system, significant reductions in the growth speed of cuttings were found, and they must be planted preferentially from 80 (clone A) to 100 (Clone B) days of age, once older cuttings undergo a reduction in the growth speed and tend to develop root malformation problems. The implications of the low quality of the root system are the mortality of plants in the field, mainly in less favorable periods, and the consequent influence on the replanting operation, as well as on the clonal tests and a greater susceptibility of plants to environment stresses.
cuttings quality; eucalypt; root system
