Enraizamento de estacas de ‘Paulsen 1103’ em diferentes substratos

Abstract

Viticulture is surrounded by increasingly pronounced challenges in the production of resistant and quality grape cultivars, making the propagation by cuttings relevant in the Brazilian and worldwide scenario. The study aimed to evaluate the propagation of cuttings from the rootstock ‘Paulsen 1103’ (‘P1103’) on different substrates. The experiment was carried out in the experimental nursery of the Federal University of Fronteira Sul, campus Cerro Largo, RS and the tested treatments were: carbonized rice husk (CRH), humus (HM), commercial substrate (CS), vermiculite (VM) and sand (SA). It was used a completely randomized design (CRD) with 5 treatments and 5 repetitions, where each repetition was made up of 10 cuttings. The characteristics of the propagation medium evaluated were: water retention capacity (WRC), electrical conductivity (EC), hydrogenionic potential (pH) and vegetative behavior of the cuttings represented by rooting percentage; volume and weighted average root diameter; sprouting; and chlorophyll index (A and B) of the leaves. The characterization of the substrates (WRC, EC, pH) was carried out 30 days after the implantation (DAI) of the experiment, the percentage of sprouting 45 DAI and the other parameters (chlorophyll index A and B, volume, weighted average diameter and rooting percentage) at the end of the experiment, totaling 60 DAI. The WRC of the substrates have different values, with the treatments VM and HM having the highest percentages (70.0 and 69.9% respectively) differing from completing the other treatments. with lower values for CRH treatment (29.4%). For the parameters EC and pH, the treatments HM and CRH showed values significantly higher than the other treatments (0.181 and 0.151 mS / cm-1 and 8.3 and 7.6 respectively), in which the SA treatment obtained the lowest values. Also, for the HM and CRH treatments, they obtained the highest pH levels (8.3 and 7.6 respectively). For root volume, the CRH and HM treatments showed the highest results (56 and 55 cm³ respectively), differing significantly from VM and SA (25 and 20 cm³ respectively), which did not differ between them. In the weighted average diameter, the HM treatment with the highest value (25 mm) stands out in comparison to the treatment SA (10 mm). The treatments VM, SA, CS and HM showed the highest percentage of sprouting (100, 96, 90 and 88% respectively), differing significantly from the CRH treatment (58%). For the chlorophyll A and B indices, the CAC treatment had the lowest indices (7.71 and 1.26 respectively), differing significantly from the other treatments, that did not differ from each other. The rooting of the rootstock ‘P1103’ did not present significant results on the analyzed substrates.