Growth, vegetative rescue and vegetative propagation in <i>Eucalyptus</i> species and hybrids

Abstract

The objective of the study was the evaluation of survival and productivity indicators in different species/hybrids of Eucalyptus in the adult stage, as well as the vegetative rescue of adult trees and cuttings, testing for species/hybrids, concentration of growth regulator and substrates in rooting. In the evaluation of species/hybrids, height (m), diameter at breast height (DBH, cm) and individual volume (m³ per individual) were measured, and survival was evaluated. In the vegetative rescue treatment, the number of shoots produced at 90, 120 and 210 days was evaluated. In the cutting experiments, the species that produced rescue shoots were tested, in addition to indole-3-butyric acid (IBA) doses (0, 1 500, 3 000 and 4 500 mg L⁻¹) and four substrates for rooting cuttings. The experiments of IBA doses and substrates were carried out using Eucalyptus saligna plants. In the cutting experiments, after 120 days of cultivation, the following variables were evaluated: callus formation (%), survival (%), rooting (%), number and length of roots. The best results regarding survival and quantitative variables of the species/hybrids were obtained for E. dunnii, E. dunnii × E. grandis and E. pellita. In the vegetative rescue, E. dunnii × E. grandis and E. pellita had the highest formation of shoots and the girdling vegetative rescue method had the best results in terms of generated shoots. E. saligna had better results regarding the variables related to the rooting of cuttings. The substrate S3 and the use of 1 500 mg L⁻¹ of  IBA provided the highest survival rate and better variables related to the rooting of the cuttings.