Resumo Sequoia sempervirens (sequoia) é uma espécie conhecida pela qualidade superior de sua madeira, sendo a produção de mudas por miniestaquia uma alternativa viável. O objetivo do trabalho foi avaliar a posição de coleta, presença ou ausência de folhas aciculares em miniestacas e a produção de mudas cultivadas em diferentes substratos e utilização de AIB. Foram utilizadas miniestacas de diferentes clones, oriundas de minijardim clonal. Para o padrão de miniestacas utilizou-se a porção lignificada, com média lignificação e pouca lignificação, na presença ou ausência de folhas aciculares, avaliando-se um clone. Em relação aos substratos, observou-se o comportamento de três clones e quatro substratos de marcas comerciais. Para o emprego de regulador de crescimento utilizou-se um clone e diferentes concentrações de AIB (0,0 a 5000 mg L-1). As miniestacas foram colocadas para enraizar em estufim e avaliadas aos 90 dias. Todos os experimentos foram instalados em delineamento inteiramente casualizado, com posterior avaliação da porcentagem de sobrevivência; porcentagem de miniestacas com calos; porcentagem de miniestacas enraizadas e número de raízes emitidas por miniestaca enraizada. Miniestacas pouco lignificadas (ápice) com folhas aciculares apresentaram os melhores resultados para sobrevivência (96%) e enraizamento (94%); miniestacas muito lignificadas sem folhas aciculares obtiveram baixo enraizamento (10%). Houve considerável variação de enraizamento entre os substratos (66 a 100%) e o número de raízes foi mais influenciado pelo clone utilizado. Os melhores resultados foram observados naqueles com componentes mais orgânicos. O emprego de AIB na miniestaquia não foi significativo para nenhuma das variáveis analisadas. Miniestacas coletadas em porções apicais e com presença de folhas aciculares mostraram-se mais indicadas para trabalhos com a espécie. Para a seleção do melhor substrato deve-se observar o efeito clonal, priorizando-se substratos com composição mais orgânica. A utilização de AIB não influenciou positivamente o enraizamento de miniestacas, não sendo recomendado o seu uso.

Abstract Sequoia sempervirens (sequoia) is a species known for the superior quality of its wood, making plants production by minicuttings a viable alternative. The objective of the work was to evaluate the position of collection, presence or absence of acicular leaves in minicuttings and production of plants grown on different substrates and use of IBA. Minicuttings from different clones, from a clonal minigarden, were used. For the minicuttings pattern, use a lignified portion, with medium lignification and little lignification, in the presence or absence of acicular leaves, available if a clone. Regarding substrates, the behavior of three clones and four substrates of commercial brands. For the growth regulator, was used a clone and different concentrations of IBA (0.0 to 5000 mg L-1). Minicuttings were placed to root in mini-tunnel and evaluated at 90 days. All experiments were installed in completely randomized design, with subsequent assessment of the percentage of survival; percentage of minicuttings with calluses; percentage of rooted minicuttings and number of roots emitted by rooted minicuttings. Little lignified minicuttings (apex) with acicular leaves, showed the best results for survival (96%) and rooting (94%); very lignified minicuttings without acicular leaves obtained low rooting (10%). There was considerable variation in rooting between substrates (66 to 100%) and the number of roots was more influenced by the clone used. The best results were observed in those with more organic components. The use of IBA in the minicutting was not significant for any of the variables analyzed. Minicuttings collected in apical portions and with the presence of acicular leaves are more suitable for work with a species. To select the best substrate, must be observe the clonal effect, prioritizing substrates with a more organic composition. The use of IBA did not positively influence or reduce minicuttings, it was not recommended or its use.

ABSTRACT Sequoia sempervirens is different from other species not only for its excellent vigor and longevity, but also for quality wood productivity. The objective of this work was to evaluate the rooting of Sequoia sempervirens mini-cuttings in different cultivation environments. In both experiments, rooting was evaluated in time to determine the root development in each environment. Mini-cuttings from clone A228 from clonal mini-garden were used. In the first experiment the material was placed to take root in three different environments: greenhouse (GH), shadehouse (SH) and mini-tunnel, with evaluation performed every 30 days (from 30 to 150 days). In the second experiment, we compared the development and rooting in mini-tunnel, greenhouse with intermittent mist (GWIM), with weekly evaluations (from 30 to 93 days). Both experiments were installed in a completely randomized design, with subsequent evaluation of the survival percentage, percentage of rooted cuttings and number of roots emitted by rooted cuttings. Humidity and temperature data were also collected in all environments observed. The mini-tunnel was the most efficient place for sequoia mini-cutting, presenting higher survival, rooting and number of roots when compared to the shadehouse and the greenhouse. In addition, it provided rooting similar to the greenhouse with intermittent mist (close to 90%). It is recommended to keep mini-cuttings in a mini-tunnel or greenhouse with intermittent mist for a period of 90 days for proper rooting to occur. Good temperature control was also observed in this structure, as well as excellent humidity control. The mini-tunnel can be used for sequoia propagation by mini-cuttings as it has shown good rooting results (> 80%).

ABSTRACT We analyzed the rooting of sequoia mini-cuttings from different clones in the four seasons of the year and the use of the logistic model to estimate the time of maximization of rooting in each factor of analysis. Mini-cuttings of five clones grown in clonal mini-garden were placed to root in mini-tunnel in four seasons of the year. Weekly evaluations were performed (from 30 to 93 days) of these variables: survival (%), rooted mini-cuttings (%) and a number of emitted roots. These data were used to adjust the original logistic function. The experiment was set in completely randomized design, in a factorial scheme of 5 (clones) x 4 (seasons), using five replicates of 50 mini-cuttings per experimental unit. During the winter the lowest rooting of mini-cuttings was achieved (85%), with rates higher than 90% in other seasons. In winter, slower rooting also occurred, around 60-70 days, while in other seasons it was between 50-60 days after mini-cutting planting. The rooting process is dependent on the clones. Our data showed that four clones presented rooting greater than 90% and one less than 70%. In general, mini-cuttings can be performed at any time of the year, recommending the period of 90 days in mini-tunnel.

RESUMO Sequoia é uma espécie de rápido crescimento, longeva e de madeira durável. O objetivo do estudo foi testar diferentes métodos de resgate vegetativo em árvores adultas de Sequoia sempervirens, realizados em distintas épocas do ano e posterior enraizamento de estacas individualizadas por planta matriz. Resgataram-se 24 indivíduos de sequoia, aplicando-se anelamento e semianelamento em três diferentes alturas (-10, 0 e 30 cm). A primeira coleta foi efetuada 90 dias após aplicação dos tratamentos, sendo repetida aos 150, 240 e 360 dias. Contabilizou-se a porcentagem de árvores com brotações e o número de brotações por matriz. Em todas as coletas as brotações originaram estacas que foram colocadas para enraizar em estufim. No enraizamento das estacas analisou-se a sobrevivência (%), enraizamento (%) e número de raízes por matriz por coleta. O resgate vegetativo da espécie mostrou-se eficiente na produção de brotações para a estaquia, destacando-se o anelamento a 30 cm e o semianelamento a -10 cm. Entretanto, há dificuldade em definir qual o melhor método, principalmente em função do efeito genético entre matrizes. O enraizamento de estacas do material resgatado apresentou bons resultados (média >65%), também com grande diferença entre as matrizes. Diferentes épocas de estaquia alteraram o potencial de enraizamento, contudo, com altos índices de enraizamento em todas as estações do ano, principalmente no verão. Sequoia sempervirens apresenta potencial de resgate vegetativo e clonagem por estaquia, sendo possível conduzir novos trabalhos com vistas a fixação de clones.

ABSTRACT Sequoia is a fast-growing, long-living species, producing durable timber. The aim of this study was to test different methods for the vegetative rescue of Sequoia sempervirens trees over 40 years old, made at different periods of the year, and, later, testing the rooting of individualized cuttings in planned arrays. Twenty-four individual sequoias were rescued, applying girdling and semi-girdling at three different heights (-10, 0, and 30 cm). The first collection was made 90 days after application of the treatments, being repeated at 150, 240, and 360 days. The percentage of budding trees and the number of shoots per array were registered. In all collections, shoots produced cuttings, which were placed for rooting in mini-tunnels. Cutting survival (%), rooting (%), and number of roots were registered, per array, and per collection. The species vegetative rescue proved to be efficient for the production of shoots for stem cuttings, especially with girdling at 30 cm and semi-girdling at -10 cm. However, it is difficult to define the best method, mainly because of the genetic effect among stock plants. The rooting of cuttings, of recovered material, presented good results (average >65%), also with great differences among stock plants. The potential for rooting of cuttings varied according to different planting periods, with high rooting rates in all seasons, especially in summer. Sequoia sempervirens shows the potential for vegetative rescue and cloning by rooting of cuttings, and this may lead to new studies, with a view towards fixing clones.

RESUMO Este artigo apresenta uma revisão sobre as micorrizas e aspectos relacionados com seu uso em espécies florestais e na biorremediação. As informações obtidas na literatura já comprovaram que os fungos ectomicorrízicos podem ser muito importantes no estímulo ao crescimento de mudas e árvores. Quanto à biorremediação, estes fungos são promissores na capacidade de degradar poluentes em solos contaminados. Nesse sentido, são apresentados os benefícios e usos destes microrganismos e as características das ectomicorrizas (ECM), que são promissoras para uso nestes processos. Apresentam-se informações sobre o uso potencial de ECM para a remediação de poluentes orgânicos persistentes e de metais pesados, bem como alguns resultados já pesquisados. Demonstra-se que, internacionalmente, o enfoque das pesquisas sobre micorrizas tem se dado com novas perspectivas, além do uso convencional para o favorecimento do crescimento das plantas.

ABSTRACT This article presents an overview of the aspects of mycorrhizas and their use in forest species and bioremediation. The information gathered from the literature had already indicated that ectomycorrhizal fungi may be very important to stimulate the growth of seedlings and trees. As for bioremediation, these fungi are promising in the ability to degrade pollutants in contaminated soils. In this sense, the benefits and uses of these microorganisms, and the characteristics of ectomycorrhizae (ECM) are presented herein, which are promising for use in these processes. Also, information on the potential use of ECM for the remediation of persistent organic pollutants and heavy metals is presented, as well as some results already searched. It is shown that internationally, the focus of the research on mycorrhizae has occurred with new perspectives, beyond the conventional use to stimulate plant growth.

RESUMO Os resíduos sólidos da indústria de reciclagem de papel têm potencial de uso para correção da acidez do solo e como fonte de nutrientes para as culturas agrícolas e florestais. Este trabalho teve como objetivo avaliar os efeitos do lodo de papel reciclado sobre o crescimento de diâmetro de colo de Eucalyptus saligna Smith, com base em um delineamento fatorial 4x2x5, sendo os fatores a dose do lodo, a adubação de cobertura e os dias após o tratamento, com 16 mudas implantadas em vasos a campo, durante 120 dias. Apesar de seu promissor uso como corretivo de solo, o lodo de papel reciclado prejudicou o desenvolvimento das plantas, e a maior dose prejudicou a adubação em cobertura.

ABSTRACT The solid waste of recycling paper industry has potential to be used for the correction of soil acidity and as a source of nutrients for agricultural crops and forestry. This study aimed to evaluate the effects of recycled paper sludge on the stem diameter growth of Eucalyptus saligna Smith, based on a 4x2x5 factorial design, being the factors the dose of the sludge, the top fertilization and the days after treatment, during 120 days. Despite its promising use as corrective of soil, sludge recycled paper hindered the development of stem diameter, and the highest dose damaged the fertilization.