Resumo Araucaria angustifolia é uma conífera nativa do Brasil de grande importância econômica. É característica da espécie a dificuldade de quebra de dominância apical e indução/crescimento de brotações múltiplas, levando a dificuldades na produção de brotações para miniestaquia e formação de copa com arquitetura mais baixa e aberta para produção de pinhão em pomares. Assim, objetivou-se avaliar a eficiência da aplicação de giberelina, o sombreamento e diferentes alturas de poda na superação da dominância apical em mudas de araucária. Mudas com aproximadamente 4 anos de idade foram submetidas a três experimentos implantados em delineamento inteiramente casualizado, sendo eles a aplicação de giberelina (0 mg L-1 GA3 e 500 mg L-1 GA3), o sombreamento (pleno sol e casa de sombra) e diferentes alturas de poda (30 cm e 60 cm) a partir do colo das mudas. A aplicação de GA3 promoveu menor número de brotações que o tratamento testemunha (0 mg L-1 GA3). Não houve influência do sombreamento no comprimento das brotações. A poda realizada a 30 cm promoveu maior número de brotações. Dessa forma, concluise que a decepa a 30 cm é indicada para produção de brotações múltiplas em A. angustifolia, não sendo necessária aplicação de GA3 e nem sombreamento das mudas para o crescimento das brotações.

Abstract Araucaria angustifolia is a native Brazilian conifer of great economic importance. The difficulty of breaking apical dominance and induction/growth of multiple shoots is characteristic of the species, leading to difficulties in the production of mini-cuttings and formation of a lower open canopy for pinion production in orchards. Thus, this study aimed to evaluate the efficiency of gibberellin application, shading and different pruning heights in overcoming the apical dominance in araucaria seedlings. Seedlings with approximately 4 years old were submitted to three experiments, which were the application of gibberellin (0 mg L-1 GA3 and 500 mg L-1 GA3); shading (full sun and shade house) and different pruning heights (30 cm and 60 cm) from the seedling neck. The application of GA3 promoted smaller number of shoots than the control treatment (0 mg L-1 GA3). There was no influence of shading on shoot length. Pruning at 30 cm promoted the largest number of shoots. Thus, it can be concluded that the cutoff at 30 cm is indicated for the production of multiple shoots in A. angustifolia, neither GA3 application nor seedling shading are necessary for shoot growth.

RESUMEN El objetivo de este estudio fue evaluar la viabilidad de la técnica de miniestacas de Ginkgo biloba, así como la influencia de diferentes sustratos y diferentes concentraciones de ácido indolbutírico (IBA) en la formación de raíces adventicias además del contenido de proteínas y azúcares en las miniestacas. Las miniestacas tenían 4 ± 1 cm de longitud, y sus bases se sumergieron en soluciones de 0, 1000, 2000 y 3000 mg L-1 IBA. Luego las miniestacas se plantaron en tubos de polipropileno usando dos sustratos (vermiculita y Tropstrato®), bajo condiciones de invernadero durante 60 d. El experimento se llevó a cabo en un esquema factorial 2 x 4 (sustratos x IBA). No hubo influencia de la aplicación de IBA en la promoción de la rizogénesis de las miniestacas de Ginkgo biloba. Los porcentajes de enraizamiento fueron superiores al 55%, independientemente del tratamiento utilizado. El sustrato de vermiculita mostró un mayor número de raíces (4.94) y menor mortalidad (11.60) de miniestacas que el Tropstrato®. Por lo tanto, se puede concluir que la técnica de miniestaca es factible para Ginkgo biloba,y que el uso de IBA no es necesario. Se encontró que la inducción de raíces adventicias depende de la composición bioquímica de las plantas madre, debido a la translocación de azúcares no reductores y proteínas de la hoja para la formación de las raíces.

ABSTRACT The objective of this study was to evaluate the viability of the Ginkgo biloba mini-cutting technique, as well as the influence of substrates and different concentrations of indole butyric acid (IBA) on adventitious rooting in addition to the protein and sugar content in the mini-cutting. Mini-cuttings were 4 ± 1 cm in length, with the bases immersed in solutions of 0, 1000, 2000, and 3000 mg L-1 IBA. They were then planted in polypropylene tubes using two substrates (vermiculite and Tropstrato®) and maintained under greenhouse conditions for 60 d. The experiment was carried out with a 2 x 4 factorial scheme (substrates x IBA). There was no influence of IBA application on the promotion of rhizogenesis in Ginkgo biloba mini-cuttings. The rooting percentages were higher than 55% regardless of the treatment used. The vermiculite substrate showed a higher number of roots (4.94) and lower mortality (11.60) of mini-cuttings than Tropstrato®. We conclude that the mini-cutting technique is feasible for Ginkgo biloba, and the use of IBA is not necessary. We found that the induction of adventitious rooting depended on the biochemical composition of the mother plants, due to the translocation of non-reducing sugars and leaf proteins for root formation.

ABSTRACT The objective of this study was to evaluate the germination potential of Aegiphila brachiata (peloteiro) and its propagation through stem-cuttings, as well as how the age of parental plants and the application indolebutyric acid (IBA) and inoculant of Azospirillum brasilense influence adventitious rooting of the species. Thus, the physical characterization of a seed lot and a germination test were performed, both with or without seed scarification and at three gibberellin concentrations (0, 50 and 100 mg.L-1 GA3). For stem-cuttings, two experiments were carried out with cuttings, one with young individuals and the other with adult trees. In both experiments, stem-cuttings were submitted to treatments with IBA (0, 1500, 3000 and 6000 mg.L-1) and a solution of Azospirillum brasilense (50% and 100% of the commercial concentration) for rooting in a greenhouse for 30 days. No seeds germinated and a barrier of radicle emission was identified in the endocarp. The inoculation of stem-cuttings with A. brasilense revealed no influence in rhizogenesis. The stem-cutting technique from young trees is recommended for plantlet production of this species (53.75% rooting), requiring 6000 mg.L-1 IBA application under the conditions that were adopted. Stem-cuttings from adult trees are not recommended for the production of plantlets of peloteiro (Aegiphila brachiata Vell.) due to the low rooting rates (10%) and high mortality (68.33%).

RESUMO Um sistema de produção de mudas eficiente, com elevada produtividade e qualidade é apresentado neste estudo para Acer palmatum. Avaliou-se a eficiência da miniestaquia, manejo das minicepas e produção de brotos em duas estações no enraizamento e vigor radicial de miniestacas. As minicepas foram plantadas em vasos de dois litros, acondicionadas em dois ambientes (pleno sol e casa de sombra) e submetidas a fertirrigação semanal. Ao longo de seis coletas avaliou-se a sobrevivência e produtividade do minijardim clonal (Experimento I). A partir destes, realizou-se dois experimentos de miniestaquia: Experimento II- miniestacas de dois ambientes, com 8±1 cm, instaladas em duas estações do ano (primavera e verão); Experimento III- miniestacas de pleno sol, com 4±1, 6±1, 8±1, 10±1 cm, instaladas no verão. O plantio das miniestacas foi realizado em tubetes de 55 cm³, preenchidos com vermiculita de granulometria fina e casca de arroz carbonizada (1:1 v/v), acondicionados em casa de vegetação com sistema de irrigação intermitente. O elevado enraizamento (95,0%), sobrevivência de minicepas (100%) e produção de miniestacas (217,5 miniestacas m-2 mês-1) em minijardim clonal conduzido a pleno sol mostram a viabilidade da técnica. Miniestacas de 8±1 cm (96,3%) favoreceram o enraizamento. A técnica de miniestaquia é viável para a espécie.

ABSTRACT This study presents an efficient system with high productivity and quality for Acer palmatum propagation. We evaluated the efficiency of mini-cuttings technique, management of mini-stumps, production of shoots, rooting and root vigor of mini-cuttings on two seasons. The mini-stumps were planted in pots of two liters, put up in two environments (full sunlight area and shade house) and submitted to weekly fertigation. Over six collections, we evaluated the survival and productivity of clonal mini-garden (Experiment I). From these, we performed two experiments with mini-cuttings: Experiment II - mini-cuttings originated from two environments, with 8±1 cm, put to root in two seasons (Spring and Summer); Experiment III - mini-cuttings originated from full sunlight area, with 4±1, 6±1, 8±1, 10±1 cm, put to root in Summer. The mini-cuttings planting was made in plastic tubes of 55 cm³, filled with fine vermiculite and carbonized rice hulls (1:1 v/v), in a greenhouse with intermittent irrigation system. The high rooting (95.0%), mini-stumps survival (100%) and mini-cuttings production (217.5 mini-cuttings m-2 month-1) in clonal mini-garden conducted in full sunlight area shown the technique viability for the species. Mini-cuttings of 8±1 cm favored rooting (96.3%). The mini-cuttings technique is viable for Acer palmatum propagation.