AGE OF STOCK PLANTS, SEASONS AND IBA EFFECT ON VEGETATIVE PROPAGATION OF ILEX PARAGUARIENSIS

ABSTRACT The low germination of Ilex paraguariensis seeds and their long reproductive cycle make cuttings propagation a good alternative for its reproduction all year round, enabling to obtain genetically superior clones. Thus, we evaluated the influence of stock plants age, plant growth regulator indole-3-butyric acid (IBA) application and plant material collection in different seasons related to rooting of cuttings. From 12 and over 80-years-old trees shoots cuttings were made in four seasons, treated with IBA hydroalcoholic solution at concentrations of 0, 1500, 3000, 4500 and 6000 mg L-1. The rooting was performed in plastic boxes filled with vermiculite and carbonized rice husk at a ratio of 1:1 (v/v) and, after 90 days in controlled greenhouse conditions were evaluated the rooting percentage, callus formation, survival, mortality, number of roots/cutting and length of three larger roots/cutting. Cuttings from 12-years-old stock plants have higher ability to form adventitious roots and the use of IBA did not increase rooting potential. Autumn proved to be the most favorable season for rooting, followed by spring and winter.