Propagation of juvenile cuttings of clones of (tropical Eucalyptus) Eucalyptus urugrandis: Examination of the role of auxins in adventitious rooting

Abstract

The objective of the research was to evaluate the vegetative development of cuttings of tropical Eucalyptus clones (Eucalyptus urugrandis) with auxin application. A factorial arrangement (7 x 6), consisting of cuttings of tropical Eucalyptus clones (EC16, EC18, EC45, LA157, LA41, LA85, LA86) and auxin doses (1500 mg kgˉ ¹ AIB, 1000 mg kgˉ ¹ AIB, and 0 mg kgˉ ¹ AIB, 1500 mg kgˉ ¹ ANA, 1000 mg kgˉ ¹ ANA, 0 mg kgˉ ¹ ANA, 0 mg kgˉ ¹ ANA), respectively, was used; for a total of 42 interactions, with three replications and four observations per experimental unit. The variables evaluated were: survival percentage, mortality percentage, rooting percentage, seedling height, number of leaves, and number of roots. The analysis of the behavior of clone cuttings in E. urograndis in the variable survival (66.74%), number of leaves ( 14), plant height (13.48), with better response to (p˂0.05) was in clone EC166 and the hormone concentration of1500 mg kgˉ ¹ AIB, not so for the number of roots ( 119) which showed better response to (p˂0.05) with 1000 mg kgˉ ¹ ANA. The highest rooting percentage (p˂0.05) was presented by clone EC 16 with 27.06%. The clonal propagation of eucalyptus with the use of auxins is a valuable milestone to promote genetically homogeneous plantations.