Período de coleta e ácido indolbutírico no enraizamento de estacas de plantas adultas de nogueira-pecã

The objective of this work was to evaluate the effect of the collection period and of the exogenous application of indolebutyric acid (IBA) on the rooting of cuttings from adult pecan ( Carya illinoinensis ) plants. The experiment was carried out in a greenhouse with intermittent mist irrigation, from December 2017 to October 2018. The experimental design was completely randomized, in a 4x5 factorial arrangement, with four collection periods (spring, summer, autumn, and winter) and five concentrations of IBA (0, 2,000, 4,000, 6,000, and 8,000 mg L -1 ). For the cuttings collected during summer and autumn, there was a linear relationship between rooting and the increase of the IBA concentration. The best results for rooting, callus formation, mean number of roots, mean root length, and root dry and fresh mass are obtained for the cuttings collected during summer, with the application of 8,000 mg L -1 IBA on the base of each cutting, under a mist irrigation system. The rooting of cuttings from adult pecan plants with the application of IBA is possible, being an alternative propagation method for the species.