THREE EPICORMIC SHOOT TECHNIQUES IN I. paraguariensis MOTHER TREES AND ITS CUTTING ACCORDING TO THE MATERIAL REJUVENATION DEGREE

Abstract

The induction of epicormic shoots is very important for the success of vegetative propagation in forestry species, due to the high rooting capacity of the reinvigorated material. However, it is necessary to determine the most appropriate technique for this purpose, aiming for greater productivity and better reinvigoration. The objective of this work was to evaluate different induction techniques for the production of epicormic shoots in I. paraguariensis mother trees in the municipality of Urupema, Santa Catarina state, considering four rescue techniques: complete girdling (100%); semi-girdling (50%); detached live branches, and; shoots of the treetop (canopy). Three evaluations were made for: trees with epicormic shoots (%), average number of shoots and their average length (cm). Shoots were collected at 180 days after (February 2017) the application of the experiment (August 2016), separating in: rejuvenated shoots and of the treetop. These were sectioned in cuttings, conditioned in the UDESC Forest Nursery, in Lages, and at 90 days were evaluated: rooting (%), calogenesis (%), average root number and their average length (cm). The semi-girdling was superior to shoot length (5.3 cm). The detached live branches the highest average number of shoots (4.7), however, they were not able for cutting, due to their very short length (0,6 cm).  For cutting, there was only difference for the number of roots formed, and the rejuvenated material was superior (2,3). It is recommended the use of semi-girdling technique for greater production of juvenile shoots and use reinvigorated cuttings for vegetative propagation, considering the greater number of roots formed.