Mini-cutting size, mini-tunnel management and phytohormones in the clonal propagation of Eucalyptus urophylla and hybrids of Corymbia spp.

Rosália Nazareth Rosa Trindade; Gabriel Faria Parreiras de Andrade; Augusto Matias de Oliveira; Miranda Titon; Márcia Regina da Costa

doi:10.53661/1806-9088202650263952

Authors

Rosália Nazareth Rosa Trindade Aperam BioEnergia, Itamarandiba, Minas Gerais, Brasil https://orcid.org/0000-0003-3873-4125
Gabriel Faria Parreiras de Andrade Universidade Federal de Viçosa, Programa de Pós Graduação em Genética e Melhoramento, Viçosa, Minas Gerais, Brasil https://orcid.org/0009-0007-1091-5860
Augusto Matias de Oliveira Universidade de Rio Verde, Departamento de Produção Vegetal, Rio Verde, Goiás, Brasil https://orcid.org/0000-0003-3556-2030
Miranda Titon Universidade Federal dos Vales do Jequitinhonha e Mucuri, Departamento de Engenharia Florestal, Diamantina, Minas Gerais, Brasil https://orcid.org/0000-0002-5940-5390
Márcia Regina da Costa Universidade Federal dos Vales do Jequitinhonha e Mucuri, Departamento de Agronomia, Diamantina, Minas Gerais, Brasil https://orcid.org/0000-0001-6273-4913

DOI:

https://doi.org/10.53661/1806-9088202650263952

Keywords:

Forest nursery, Plant growth regulators, Forestry

Abstract

The area planted with Corymbia spp. clones is expected to increase in the coming years, despite their propagation challenges. This study aimed to evaluate mini-cutting size, mini-tunnel opening time, and the use of growth regulators in the clonal propagation of Corymbia spp. Four experiments were conducted using three clones: C. citriodora × C. torelliana, C. torelliana × C. citriodora, and E. urophylla, where E. urophylla was used as a control due to its ease of propagation. The results from each experiment were used to optimize the methodology for the subsequent one. Initially, three mini-cutting sizes were tested: 5, 10, and 15 cm in length. The second experiment evaluated three collection times of mini-cuttings after mini-tunnel opening: 0, 24, and 48 hours. The third experiment tested five concentrations of indole-3-butyric acid (IBA): 0, 500, 1000, 1500, and 2000 mg kg⁻¹. Finally, five concentrations of a formulated product containing different plant growth regulators (0, 1, 2, 3, and 4 mL L⁻¹) were assessed. All experiments were arranged in a randomized block design in a factorial scheme according to genotype. The following variables were evaluated: final rooted mini-cutting yield, survival, plant height, root length, and root, shoot, and total dry mass. Mini-cuttings of 15 cm performed best in promoting the growth of both hybrids. Regarding mini-tunnel opening time, the 24-hour interval after opening was optimal for C. citriodora × C. torelliana. Applications of 2000 and 1000 mg kg⁻¹ IBA promoted rooting in Corymbia spp., and rooted mini-cutting quality was improved with the application of 4 mL L⁻¹ of the growth regulator formulation.

Keywords: Forest nursery; Plant growth regulators; Forestry