Influence of the degree of lignification and use of indole-acetic acid on the development and rooting of Libidibia ferrea cuttings

Libidibia ferrea (Mart. ex Tulle.) L.P. Queiroz, commonly known as pau-ferro and belonging to the Fabaceae family, is a species valued in traditional Brazilian medicine, promoting research in pharmacological and biotechnological products. However, seed propagation faces obstacles due to seed coat dormancy, which reduces germination rates, and genetic variability, which can lead to biochemical differences in compounds of interest, complicating standardization for the pharmaceutical industry. Thus, vegetative propagation emerges as a promising alternative to overcome these challenges. In this context, this study evaluated the effect of juvenility and indole acetic acid (IAA) on the rooting of L. ferrea cuttings, in addition to anatomical characterization of the cuttings to identify potential barriers to rooting. The experiment was conducted at INPA, Manaus – AM, using regrowth and juvenile cuttings prepared with one or two leaves cut in half and treated with IAA at concentrations of 0, 500, 1000, and 2000 mg L-1. After 60 days in a rooting greenhouse, the results show that regrowth cuttings had higher leaf retention (78.8%), callus formation (84.6%), rooting (65.4%), and average root number (3.0), underscoring the influence of tissue rejuvenation on rooting success. Juvenile cuttings exhibited greater bud formation (59.6%) and survival rate (86.5%), indicating that juvenility favors budding and survival. Therefore, the propagation of L. ferrea by cutting is viable and is enhanced when combined with rejuvenation techniques and the application of IAA, especially at a dose of 1000 mg L⁻¹.