Effect of Cutting Size on the Performance of Exogenous Auxin IBA in Vegetative Propagation of Rubus erythroclados Mart. ex Hook. f.

Aim: The climbing shrub Rubus erythroclados Mart. ex Hook. f. (amora-verde) has great food (fruits) and medicinal (leaves) potential. However, this species remains understudied. The objective of this study was to evaluate the interaction between cutting size and IBA concentration in the vegetative propagation of R. erythroclados by stem cuttings. Study Design: The experimental design used was completely randomized in a 3x5 factorial combination. The cutting size factor was represented by three levels (10, 15 and 20 cm) and IBA concentration factor by five levels (0, 1,000, 2,000, 3,000 and 4,000 mg L-1). Results: There was an interaction between the factors in 13 of the 19 variables analyzed, being: live cuttings at 30 and 60 days, live cuttings with callus formation, sprouted cuttings at 30, 60 and 90 days, rooted cuttings, shoot number, shoot diameter, root number, root length, length of the largest root and root diameter. Size increase of the R. erythroclados cuttings caused a decrease in the phytotoxic effect of IBA in the development of the aerial part. The effect of IBA in response to rooting induction, in the larger size of R. erythroclados cuttings, required an increase in IBA concentration compared to the cuttings of shorter size. Conclusion: Cuttings of 10 and 15 cm treated with 1,000 mg L-1 of IBA showed greater rooting (20.0%) compared to the other treatments, being, therefore, indicated for the vegetative propagation of R. erythroclados by stem cuttings.