Regulador de crescimento e substratos na propagação de espécies frutíferas

Abstract

With the aim of evaluating and determining the concentration of IBA in the rooting of cuttings of different peach cultivars and testing different substrates in the sexual propagation of sour passion fruit seedlings, the study, consisting of two experiments, was conducted under a screen and in a glass greenhouse, respectively. The first experiment aimed to evaluate different concentrations of indolebutyric acid (IBA) (0 mgL-1; 1.000 mgL-1; 2.000 mgL-1 and 3.000 mgL-1) in the rooting of semi-hardwood cuttings of three peach tree cultivars (BRS Sensação, Jade and Chimarrita). The experimental design was blocks, in a 4 x 3 factorial arrangement (IBA concentrations x cultivars), with four replications, with each experimental unit consisting of 10 cuttings and 40 per treatment. At 90 days, evaluations were carried out on the percentage of rooting, survival, number of roots and average length of the largest root per cutting. An interaction was observed between the factors studied. It was concluded that IBA concentrations close to 1.452 mgL-1 to 2.500 mgL-1 were considered ideal for rooting semi-hardwood cuttings of the tested cultivars, as they presented better responses for all variables analyzed. For the Chimarrita cultivar, higher survival rates were observed compared to the others at a concentration of 1.575 mgL-1, reaching 85%. In the second experiment, four substrates were evaluated: soil; soil + organic compound (1:1); organic compost and Fertile Peat®, in the production of sour passion fruit seedlings of the SCS437 Catarina cultivar. The experiment was conducted following the same design as the first, in a 4 x 1 arrangement (substrate and cultivar), with each experimental unit consisting of 10 plants and 40 per treatment. Evaluations of the emergency percentage were carried out; emergency speed index; average emergency time; average emergence speed and Timson emergence index (which occurred in the period from 15 to 31 days after sowing); plant height; diameter of the plant neck and average number of leaves evaluated 120 days after sowing. There was a statistical difference between the treatments. It was found that the seedlings grown in the T1, T2 and T3 substrates presented inferior results when compared to those grown in the T4 substrate based on Fertile Peat®, for all the variables analyzed. Under the conditions under which the study was carried out, the use of the substrate Turfa Fértil® for the production of sour passion fruit seedlings of the SCS437 Catarina cultivar is the most recommended. The application of growth regulators resulted in effective rooting and survival in cuttings of peach cultivars, and the type of substrate proved to be an extremely important factor for the production and quality of sour passion fruit seedlings.