Abstract

To produce seedlings with quality is one of the factors that mostly contribute to increase the production chain of a fruit crop. The use of organic substrates in the production of seedlings becomes a way to reduce costs by using raw material available regionally. Then, the aim of this study was to evaluate the influence of rooting inducers and the contribution of organic substrates to improve the rooting of herbaceous cuttings of 'Paluma' guava. The experiment was completely randomized arranged in a 5×2 factorial design with 4 replications and 10 cuttings per plot. The factors comprised five substrates (S1-100% OC; S2-25% CRH + 75% OC; S3-50% CRH + 50% OC; S4-75% CRH + 25% OC; S5-100% CRH), where CRH: carbonized rice husk and OC: organic compost, and 2 rooting inducers (Radimaxi 20® and Indolbutyric Acid - IBA), with the concentration of 2000 mg L-1. With regard to the analyzed variables, rooting, mortality, length of roots, and dry weight of shoots and roots did not fit with any regression model. However, the live rootless cuttings, callus, sprouting, leaf retention, and number of roots showed interaction between the inducers and the used substrates. The maximum rooting percentage obtained was 20%, independently of the type of inducer or used substrate; the use of Radimaxi 20® provides greater percentage of cuttings with callus and live rootless cuttings; the carbonized rice husk in composition S2 (25% CRH + 75% OC) is indicated to compose the rooting substrate of 'Paluma' guava cuttings; despite the satisfactory results obtained in this work, more studies are needed to clarify the rhizogenic process of guava in diversified conditions.

Key words: Indolbutyric acid, vegetative propagation. Radimaxi 20®.