Rooting cuttings of Ilex paraguariensis native to southern Brazil according to mother tree genotype, rooting environment and IBA use

Abstract

Vegetative propagation is an effective tool for the establishment of plants with superior characteristics. Therefore, it is necessary to test the rooting of each genotype in relation to the environment and observe the response of the species to the use of growth regulators. The objective of this search was to evaluate the rooting of Ilex paraguariensis cuttings according to genotypes in two environments, and test doses of IBA. The cuttings were obtained in Urupema, Santa Catarina. Mother trees 15 years old on average, were selected randomly, and canopy shoots were collected and transported to UDESC, in Lages. The shoots were sectioned into cuttings and put to root according to the experiments: I) Six genotypes were conditioned in two environments: a mini tunnel system and a greenhouse with intermittent nebulization (GWIN) with temperature control, II) In a mini tunnel with IBA concentrations: (mg L-1): 0, 2,500, 5,000, 7,500 and 10,000. Survival (%), callus (%), rooting (%), number and mean root length (cm) were evaluated. Survival was superior in mini tunnels (>20.0%), but its rooting percentages were lower (35.0%) than the GWIN (>50.0%). Genotype G6 was higher in all variables, with survival (>70.0%) and rooting (>30.0%). The highest IBA dose reached twice as much rooting as the control, but it was still low (15.0%). The correct selection of the genotype and environment are crucial for the successful rooting of I. paraguariensis cuttings. In addition, rooting seems to be more associated to the time factor than to the use of IBA itself.