Bioestimulante no enraizamento ex vitro de microestacas de três comprimentos do clone de Eucalyptus grandis X Eucalyptus urophylla

Abstract

The technical-scientific evolution of Eucalyptus in clonal forestry has been occurring rapidly in recent years, promoting large-scale forest plantations with species of the genus. However, there are still some genotypes of the genus that, for different physiological reasons, have their propagation still restricted. The hybrid Eucalyptus grandis x Eucalyptus urophylla presents some clones with difficulties in the production of adventitious roots, making the success of this propagation technique difficult, as it basically depends on the rhizogenic potential. The good potential of the species generates the need to carry out new tests to reach clonal propagation efficiently, testing new products that can stimulate rooting and enabling the production of seedlings of genetic materials that present low rhizogenesis and vigor. The objective of this work was to evaluate the microcutting length and application method of the Algaren Twin® biostimulant for vegetative propagation of a clone of Eucalyptus grandis x Eucalyptus urophylla, through microcutting. The experiment was installed in a completely randomized design, in a 3 x 3 factorial arrangement (length of micro-cuttings x method of product application), totaling nine treatments, with three replications. The experimental units for length 4.0 cm consisted of 4 micro-cuttings per repetition, for length 2.5 cm consisted of 29 micro-cuttings per repetition and for length 1.5 consisted of 24 micro-cuttings per repetition. The microcuttings were inserted into biodegradable 63.61 cm3 Ellepot® tubes with commercial substrate. The data obtained from the evaluations were submitted to normality test, analysis of variance (ANOVA), and Tukey's mean comparison test at 5% probability for the qualitative factor and linear regression analysis for the quantitative factor (p ≤0 ,05). When leaving the acclimatization house after 50 days, it was found that the concentration of the Algaren Twin® biostimulant and the application methods used did not present satisfactory results in rooting the micro-cuttings. The length of micro-cuttings was shown to be a significant factor for the growth in height, stem diameter, length of the longest adventicious root and percentage of survival.