Propagação de Paratecoma peroba por miniestaquia

Abstract

The forest species Paratecoma peroba (Record and Mell) Kuhlm, belongs to the family Bignoniaceae, being native to the Atlantic Forest, presenting relevant ecological and economic interest. It has a restricted area of natural occurrence within the coastal forests of eastern Brazil. The beauty and quality of its wood has led to intense exploitation in the past, which culminated in the decline of the species' populations. It is currently in critical danger of extinction. The seeds of the species P. peroba lose their viability quickly, which restricts the production of seedlings. Due to the species' vulnerability, studies are needed to assess conservation methods and propagation alternatives. Thus, the aim of this study was to analyze the viability of the mini-cutting technique in the vegetative propagation of P. peroba. The experiments were carried out at the Department of Forestry and Wood Sciences of the Center for Agricultural Sciences and Engineering belonging to the Federal University of Espírito Santo, city of Jerônimo Monteiro, Espírito Santo state, Brazil. The thesis was structured in four chapters. In chapter 1, a vegetative propagation protocol via mini-cuttings was established for P. peroba. For this purpose, the influence of the substrate, indole-3butyric acid (IBA), the type of mini-cutting and leaf area on the rooting of mini-cuttings was analyzed. In chapter 2, the objective was to analyze the effect of substrates formulated based on different proportions of bovine manure in different volumes of tubes in the rooting and growth of P. peroba seedlings propagated by mini-cutting. In chapter 3, the objective of this study was to analyze the effect of different doses of controlled release fertilizer (CRF) on rooting, growth, photosynthetic metabolism and nutritional balance of P. peroba seedlings propagated by mini-cutting. In chapter 4, the objective was to analyze the influence of the environment and the mineral fertilization of potassium (K) on productivity, ecophysiology and nutrition of parent plants and the residual effect on rooting mini-cuttings. The results indicate that the species is capable of mini-cutting with up to 82.5% rooting. The substrate affects rooting, sand and other dense materials are not indicated. The IBA promotes linear reduction of rooting. The use of mini cuttings with 10 cm and 100% of the leaf area is recommended. The tube of 180 cm3, and the commercial substrate based on Pinus enriched with CRF in the dose 6 kg m-3 is efficient in the production of seedlings of the species. The results also show that higher temperatures, lower air humidity, higher DPV and atmospheric CO2 stimulate productivity and promote a better nutritional balance of parent plants. High humidity environments are not suitable for the cultivation of P. peroba parent plants. Mineral fertilization with K positively influences chlorophyll concentration and gas exchange. The environment and K did not influence the rooting percentage of the mini stakes of the species. These discoveries will guide conservation practices for P. peroba and the production of clones for commercial plantations.