ABSTRACT Podzols are highly sandy soils, in which elements, such as potassium, needed by crops, are easily leached. Studies have indicated that biochar can contribute to increasing cation exchange capacity of the soil, which can improve the retention of bases. This study aimed to evaluate the effect of the poultry litter biochar combined or not with increasing doses of KCl, on leaching and soil base content, on the production of green manure biomass, and on the distribution of K in the soil-water-plant system. A 2 × 3 factorial experiment was conducted in randomized blocks with 6 repetitions: without and with biochar (1% v / v, produced from poultry litter) × without K, with 53.65 and 107.30 mg dm-3 of K (as KCl). The experiment was carried out in four steps: Step 1) Soil incubation with the treatments (for 20 days) followed by chemical analysis of the soil; Step 2) First leaching: the containers (made with PVC with 0.30 m high) received the newly incubated soil in the surface layer and soil without treatment in the subsurface layer. The containers received water until saturation plus 50 % of the total pore volume and the leached water was collected and analyzed; Step 3) Cultivation of green manure (Mucuna aterrima) in the containers of Step 2 and harvest within 40 days (evaluation of biomass and K content); Step 4) after the mucuna harvest, the containers were subjected to second leaching. The leaching solution and the soil from the surface and subsurface layers were collected for chemical analysis. Biochar increased the pH, cationic exchange capacity, P, K, Ca, and Mg levels in the newly incubated soil, in the surface and subsurface layer. The increasing doses of KCl proportionally increased biomass production and K accumulation in green manure, and the biochar increased this response and reduces the need for potassium fertilization by 50 %. With biochar, the accumulation of total K in the soil-plant-water system increases by 125 % and, in the soil-plant system, by 145 %. Biochar changes the K ratio in the soil-plant-water system. With biochar, proportionally, the highest accumulated percentage of K occurred mainly in the soil surface and subsurface layer, and did not result in higher percentages of K in the leached water. Biochar produced from poultry litter can be used as a good alternative to improve the chemical properties of Podzols and reduce nutrient losses.

ABSTRACT Background: Background: Eucalypt harvest residues are critical to nutrient balances and forest soil productivity mainly in areas with consecutive forest rotations. However, nutrient release and their relations over decomposition are still poorly understood in tropical sites. We aimed to understand how nutrients are released from leaves, branches, and bark (as harvest residues), and how nutrient concentrations could be limiting the decomposition of each fraction. We measured mass loss and nutrient release of Eucalyptus urophylla x Eucalyptus grandis harvest residues for 365 days in Southeast Brazil. Results: Results: Leaves fraction showed a faster decomposition rate than branches and bark, but nutrient accumulation was observed for all harvest residues, especially bark and branches at later stages of the decomposition. Decomposition of all harvest residues seemed to be P-limited with a stronger limitation occurring for leaf litter decomposers. The decomposition of more lignified residues such as bark and branches was less influenced by climatic variables than leaf decomposition. Conclusion: Conclusion: Eucalypt harvest residues had a great contribution to soil fertility, and retaining them in the soil systems will enhance soil fertility in the short (leaves) and long-term (branches and bark) and can partially supply the nutrients for the next rotation.

ABSTRACT Background: Despite the importance of Plathymenia reticulata for forestry and ecological purposes, a protocol for the vegetative propagation of the species remains unclear mainly due to the low adventitious rooting of the propagules of the species. In this sense, this work aimed to evaluate the rooting of mini-cuttings of juvenile materials of P. reticulata and our hypothesis: (1) maintaining propagules under mist chamber for different periods affects the rooting process; (2) the mini-stump management system due to the restriction of the root system affects the production of mini-cuttings and the quality of clonal seedlings. Results: It was not necessary for more than 30 days in a mist chamber to induce rooting. The highest percentage of rooting was obtained 50 days after staking. Mini-gardens set up in suspended seed bed and tubes (280 cm3) had the average mini-cuttings productivity of 4.32 and 2.06, respectively, over 270 days of exploration (monthly collections). At 120 days after staking, there was no difference in the survival and in the final quality of clonal seedlings produced. However, clonal seedlings from mini-garden in tubes had higher height, leaf area, and number of first-order roots. Regardless of the mini-garden management, the clonal seedling production index was 50%. Conclusion: We can conclude that P. reticulata seedling production via mini-cutting technique is possible.

Resumo O estado nutricional da planta-matriz é imprescindível para a manutenção do seu vigor vegetativo, fundamental para a produção de miniestacas. Portanto, o fornecimento de nutrientes em quantidades ideais durante o manejo das minicepas influencia o sucesso da propagação. Objetivou-se com este estudo avaliar e comparar a produtividade do minijardim, os nutrientes exportados pelas brotações de três clones de Toona ciliata var. australis e o consumo total destes nutrientes durante o período de produção. Em cada coleta de brotação foi quantificada a sobrevivência, o número de brotações e de miniestacas produzidas por minicepa e, realizado o monitoramento nutricional em 18 coletas. Ao final, as minicepas foram extraídas dos canaletões para realizar a análise nutricional completa. São apresentadas as curvas de consumo durante 432 dias e os valores totais utilizados no processo. Ao final de 18 coletas de brotações, o clone TC3 foi mais produtivo. Os clones TC3 e TC15 são mais eficientes na conversão dos nutrientes absorvidos para produção de brotações e de miniestacas. A partir da 10ª coleta de miniestacas é indicada a reposição nutricional visando manter a produtividade do minijardim sempre constante. O potássio, o nitrogênio e o cálcio são os nutrientes mais exportados pelas coletas das brotações dos três clones de cedro-australiano.

Abstract The nutritional status of the mother plant is essential for the maintenance of vegetative vigor, vital for the production of cuttings. Therefore, the supply of nutrients in optimal amounts during handling of ministumps influences the success of propagation. The objective of this study was to evaluate and compare the productivity of minigarden, nutrients exported by the shoots of three clones of Toona ciliata var. australis and the total consumption of these nutrients during the production period. In each budding collection, the survival was measured, the number of shoots and cuttings produced by the ministump and, the nutritional monitoring was carried out in 18 collections. In the end, the mini-stumps were drawn from gutters to perform a complete nutritional analysis. the consumption curves for 432 days and the total amounts used in the process are presented. The TC3 clone was more productive in the 18 collections of shoots. The TC3 and TC15 clone were more efficient at converting nutrients absorbed to produce sprouts and cuttings. From the 10th collection of cuttings is shown nutritional supplementation to maintain the productivity of the always constant mini-garden. The potassium, nitrogen and calcium are the most exported nutrients by the shoots of the Australian cedar clones.

Resumo O trabalho teve como objetivo avaliar o uso do lodo de esgoto tratado (LET) associado a substrato à base de casca de pinus (SC1) ou à base de fibra de coco (SC2), em diferentes proporções, como substrato para produção de mudas de vinhático. O experimento foi conduzido em casa de vegetação, localizada na unidade de apoio a pesquisa da Universidade Estadual do Norte Fluminense, de junho a novembro de 2016. Utilizaram-se 20, 40, 60, 80% de LET associados ao SC1 ou ao SC2, 100% de LET e o tratamento com SC1 com adubação convencional (controle). O lodo de esgoto foi higienizado com adição de cal a 15% do peso seco. Os resultados revelam que as menores proporções de LET no substrato resultaram em mudas com melhor crescimento em altura, diâmetro do coleto, área foliar, massa seca da parte aérea e do sistema radicular, comprimento e volume radicular. A nodulação foi negativamente influenciada nas mudas produzidas em proporções acima de 20% de LET. A agregação do torrão ao substrato não foi influenciada pela adição de LET, entretanto, houve aumento da curvatura do torrão nas mudas produzidas em maiores quantidades de LET. O conteúdo da parte aérea de N, P e K foi menor nas mudas produzidas em substrato com LET. Para produção de mudas de vinhático, sugere-se a proporção de 20% de lodo de esgoto associado ao SC1 ou SC2, não havendo prejuízos em relação às mudas produzidas em substrato comercial adubado, utilizado comercialmente.

Abstract The aim of this work was to evaluate the treated sewage sludge (LET) associated with commercial substrate based on pinus bark (SC1) or based on coconut fiber (SC2), in different proportions, as substrate for the production of vinhático seedlings. The study was led in a greenhouse, located in the research support unit of the State University of North Fluminense. The treatments considered as substrates were 20, 40, 60, 80% of LET associated with SC1 or SC2, 100% of LET and the treatment with SC1 with conventional fertilization (control). The sewage sludge was sanitized with addition of lime to 15% of dry weight. The results showed that the lower LET proportions in the substrate resulted in seedlings with better growth in height, stem diameter, leaf area, dry mass of shoot and root system, root length and volume. The nodulation was negatively influenced in the seedlings produced in proportions above 20% LET. The aggregation of the clod was not influenced by the addition of LET, however, there was increase of the curvature of the clod in the seedlings produced in larger amounts of LET. The shoot content of N, P and K was lower in the seedlings with LET. For the production of vinatic seedlings, 20% of sewage sludge associated with SC1 or SC2, is suggested, with no losses in relation to the seedlings produced in commercial substrate that received fertilization, used commercially.

Resumo As plantações florestais estabelecidas com mudas apresentam heterogeneidade e dificuldades de manejo. Assim, uma alternativa a estes obstáculos é o uso de clones com alta produtividade. Além disso, as plantas clonais diferem das plantas seminíferas na estrutura do sistema radicular, o que pode influenciar a eficiência na absorção de água e de nutrientes minerais e, portanto, a produtividade. Nesta pesquisa, avaliaram-se as trocas gasosas foliares, a condutividade hidráulica da raiz, a eficiência no uso da água e o crescimento de plântulas de estacas clonais e de plantas propagadas por semente da espécie Toona ciliata. O estudo foi realizado em delineamento inteiramente casualizado com quatro tratamentos: a) clone TC3; b) clone TC9; c) clone TC15 e d) mudas seminíferas, com cinco repetições e dez plantas por parcela. Aos 120 dias, a taxa fotossintética líquida, a transpiração e a condutância estomática foram avaliadas entre as 12h00 e as 13h00 horas, e a partir desses valores foram calculados as eficiências instantânea (A/E) e intrínseca (A/gs) do uso da água. A condutividade hidráulica da raiz (K root) foi obtida pela aplicação de pressões crescentes (0,1, 0,2, 0,3 e 0,4 MPa) neste órgão por meio de uma câmara de pressão. A altura, o diâmetro do caule, a área foliar, a massa seca da parte aérea e raiz, o comprimento, o diâmetro, a área superficial e o volume radicular foram determinados. Os dados foram submetidos à correlação de Pearson e à análise de variância, comparando-se pelo teste de Tukey (5%). Os materiais genéticos estudados tiveram igual capacidade de absorção e transporte de água através das raízes, apesar de terem diferenças anatômicas visuais do sistema radicular. Os clones tiveram taxas de transpiração e taxa fotossintética líquida reduzidas, e estes foram mais eficientes no uso da água. Os clones TC3 e TC9 foram mais eficientes na conversão do carbono assimilado em biomassa.

Abstract Forest plantations established with seedlings have heterogeneity and are difficult to manage, so an alternative is the use of clones with high productivity. In addition, clonal plants differ in the structure of the root system that can influence the water and nutrient uptake efficiency and therefore productivity. We evaluated leaf gas exchange, root hydraulic conductivity, and water use efficiency of Toona ciliata clonal cuttings and the seedlings growth. The study was performed in a completely randomized design with four treatments: a) TC3 clone; b) TC9 clone; c) TC15 clone and d) seedlings with five replicates and ten plants per plot. On the 120th day, the net photosynthetic rate, transpiration and stomatal conductance were evaluated between 12:00 and 13:00 hours and the values calculated as efficient, instantaneous (A/E) and intrinsic (A/gs) water use were calculated. Hydraulic root conductivity (kroot) was obtained by applying increasing pressures (0.1, 0.2, 0.3, and 0.4 MPa) using Scholander chamber. The height, stem diameter, leaf area, dry mass of shoot and root, length, diameter, surface area and root volume were also determined. The data were submitted to Pearson’s correlation and analysis of variance, comparing by Tukey’s test (5%). The genetic materials studied presented an equal capacity of water absorption and transport by the roots, even though they exhibited a visual anatomical difference of the root system. Although, the clones exhibited low transpiration and net photosynthetic rates, they were generally more efficient in water use, and the TC3 and TC9 clones were more efficient to convert the assimilated carbon to biomass.

RESUMO Este estudo avaliou as correlações de diferentes características de mudas, no viveiro, de três clones híbridos de Eucalyptus grandis × Eucalyptus urophylla e o crescimento em altura após o plantio. A característica que apresentou maior correlação com o crescimento inicial foi a relação entre o comprimento da copa e a altura da muda. Aos 12 e 24 meses no campo, o diâmetro do caule foi mais importante. Os parâmetros avaliados no viveiro que se correlacionaram positivamente com o crescimento no campo aos três e seis meses após o plantio foram altura, número de pares de folhas, número de deformações radiculares e comprimento de torrão. Aos 12 e 24 meses os parâmetros que se correlacionaram negativamente foram diâmetro, número de pares de folhas e número de deformações radiculares. Apesar de apresentar correlação significativa, as deformações das raízes não interferiram no crescimento inicial das plantas sob condições de alta pluviosidade, mas os efeitos se tornaram prejudiciais ao longo do tempo, resultando em uma redução no crescimento das plantas.

ABSTRACT This study assessed correlations of different characteristics of cuttings in the nursery of three hybrid clones of Eucalyptus grandis × Eucalyptus urophylla and growth in height after planting. The characteristic that presented greatest correlation with the initial growth was the canopy height and cutting height ratio. At 12 and 24 months in the field, the stem diameter was more important. The parameters assessed in the nursery that correlated positively with growth in the field at three and six months after planting were height, number of leaf pairs, number of root deformations and clod length. At 12 and 24 months the parameters that correlated negatively were diameter, number of leaf pairs and the number of root deformations. Despite presenting significant correlation, root deformations did not interfere in the initial growth of the plants under high rainfall conditions, but the effects became harmful over time resulting in a reduction in plant growth.

ABSTRACT The aim of our study was to evaluate the dendrometric characteristics of Atlantic Forest trees of 21 years of deployment in the mountain region of Rio de Janeiro, Brazil and their influence on topsoil fertility. We evaluated the survival rates, total heights, and diameters at 1.30 m of all trees in the stand. The characterized soil chemical attributes were pH, P, K, Ca, Mg, Al, and organic matter at 0-0.1 m depth. The averages were compared by Student’s test (p<0.05). While Myroxylon peruiferum and Amburana cearensis had lower survival rates than the other species, Plathymenia reticulata had a larger diameter. All tree species showed diameter growth, though it was larger for Dalbergia nigra, Plathymenia reticulata, Schizolobium parahyba, Esenbeckia leiocarpa, and Lecythis Pisonis. All stands showed medium organic matter content, from 3.3 to 4.1%, and low P. The soils under the Dalbergia nigra and Plathymenia reticulata stands are the most acidic and with low Ca, Mg, and K levels. Our study demonstrated differences in growth patterns and that the species influenced the soil chemical characteristics differently.

RESUMO O vinhático (Plathymenia reticulata Benth) é uma das espécies nativas do Brasil, de interesse econômico e ambiental. Sua propagação tem sido realizada por sementes, entretanto, o difícil acesso às matrizes, os intervalos longos de frutificação e dificuldade de armazenamento destacam a importância de técnicas que permitam a propagação clonal da espécie. Estudos conduzidos com minicepas de vinhático, advindas de mudas produzidas por sementes têm demonstrado que, embora as minicepas apresentem boa brotação, o enraizamento das miniestacas é muito baixo. Com isso, objetivou-se neste trabalho, avaliar a produção de mudas de vinhático por miniestaquia, utilizando diferentes técnicas de manejo para induzir o enraizamento. Foram realizados dois experimentos em casa de vegetação, sendo que, no primeiro, as minicepas foram obtidas a partir de mudas produzidas via semente de progênies de onze matrizes, das quais se promoveu a coleta sucessiva de miniestacas, sendo estas submetidas a diferentes concentrações do regulador de crescimento AIB (0, 2.000, 4.000, 6.000 e 8.000 mg.L-1). No segundo experimento foi utilizado o manejo de luz (sombreamento na base da brotação e sombreamento total da minicepa) e de nutriente, com aplicação de nitrogênio (4 g.L-1 de ureia) nas minicepas. As miniestacas produzidas foram avaliadas quanto à capacidade de enraizamento e anatomia na base da miniestaca. No primeiro experimento verificou-se uma variação de sobrevivência e tolerância à poda apical entre as progênies das matrizes analisadas, com destaque para progênie da matriz DOM, que apresentou o maior percentual na primeira coleta (88,2%), e uma sensibilidade das progênies NELI, ZE1 e ZE2 aos efeitos do manejo e às condições ambientais no minijardim clonal. O vinhático respondeu de forma positiva à coleta sucessiva de brotações, com aumento do número de brotações produzidas a partir do quarto mês de coleta (210 dias). Não houve efeito significativo no enraizamento de mudas de vinhático quando submetido a concentrações crescentes de AIB, nem quanto ao tipo de manejo de luz e nitrogênio utilizados para estimular o enraizamento de miniestacas. Não foram observadas barreiras anatômicas ao enraizamento dos clones nos diferentes tipos de manejos avaliados.

ABSTRACT Vinatic (Plathymenia reticulata Benth.) is one of the native species of Brazil, of economic and environmental interest. Its propagation has been carried out by seeds, however, the difficult access to the matrices, long intervals of fruiting and difficulty of storage, emphasize the importance of techniques that allow the clonal propagation of the species. Studies conducted with vinatic minitumps, coming from seedlings have shown that although the ministumps show good sprouting, the minicutting rooting is very low. The aim of this study was to evaluate the production of vinatic seedlings by minicutting using different management to induce rooting. Two experiments were carried out in a greenhouse and, in the first experiment, the minitumps were obtained from seedlings produced from progenies of eleven matrices, from which the successive collection of minicuttings was promoted, these being submitted to different concentrations of the IBA growth regulator (0, 2.000, 4.000, 6.000 and 8.000 mg.L-1). In the second experiment, light management (shading at buds base and total shading of minitump) and nutrient were used, with nitrogen application (4 g.L-1 urea) in the minitumps. The minicuttings produced were evaluated for rooting capacity and anatomy at the base of the minicuttings. In the first experiment there was a variation of survival and tip pruning tolerance among the progenies of the matrices analyzed, with emphasis on progeny of the DOM matrix, which presented the highest survival percentage in the first collection (88,2%), and a sensitivity of NELI, ZE1 and ZE2 progenies to the management in the clonal minigarden. Vinatic responded positively to the successive collection of sprouts, with an increase in the number of sprouts produced from the fourth month of collection (210 days). There was no significant effect on rooting of vinatic plants when submitted to increasing concentrations of IBA, nor on the type of light and nitrogen management used to stimulate the minicuttings rooting. No anatomical barriers were observed to the rooting of the minicuttings in the different managements evaluated.

ABSTRACT Khaya ivorensis stands out because of the quality of the wood and high economic value. Its propagation has been carried out by seeds, an obstacle in the production in large scale seedlings, since the seeds present high value and they result in heterogenous stands. The vegetative propagation is an alternative to overcome these problems. The aim of this work was to verify the feasibility of mini-cutting for african mahogany, evaluating the pro- ductivity of the mini-stumps, the rooting of mini-cuttings using different concentrations of IBA and the clonal seedlings quality. The mini-stumps were produced from seeds in tubes, pruned at 8 cm, at 60 days. At 100 days after apical pruning, the fi rst sprouts col- lection was performed, and the mini-cuttings were submitted to concentrations of IBA (0; 2,000; 4,000 and 6,000 mg.L-1) for rooting evaluation. The seedlings were transplanted to clonal mini-garden, in which four collections of mini-cuttings were performed. Clonal seedlings quality was evaluated at 120 days after staking. The species showed tolerance to apical pruning and successive collections of mini-cuttings, with 96.4% survival and more than 92% of the mini-stumps producing mini-cuttings. It was observed 100% survival and rooting of mini-cuttings. There was no effect of the IBA on the rooting percent- age of the mini-cuttings, however, the higher concentration of IBA increase the thinner root production. The fi nal clonal seedling quality has similar growth for all treatments.

RESUMO Associações simbióticas de espécies arbóreas com fungos micorrízicos podem proporcionar o maior crescimento e nutrição das mudas, sendo alternativas importantes para o estabelecimento no campo, principalmente em áreas com restrições edáficas ou para espécies com alta exigência nutricional. No Brasil, o cultivo de Tectona grandis (teca) tem sido realizado em regiões do cerrado, em solos de baixa fertilidade. O presente trabalho objetivou avaliar o efeito da inoculação de fungos micorrízicos arbusculares (FMAs) sobre o crescimento e nutrição mineral de mudas de teca. O experimento foi realizado em delineamento em blocos casualizados (seis blocos), com quatro tratamentos: 1) Testemunha (sem inoculação de fungos micorrízicos); 2) Inoculação com Rhizophagus clarus; 3) Inóculo de FMAs obtido de plantio de teca no Mato Grosso (inóculo MT) com vinte anos; e 4) Inóculo de FMAs nativos de cava de extração de argila de Campos dos Goytacazes (inóculo de Campos). As plântulas foram inoculadas e cultivadas em vasos de 6 dm3, por 135 dias, e foram avaliadas quanto à altura e ao diâmetro da base do caule. Amostras de raízes foram coletadas para avaliação da porcentagem de colonização com FMAs. As raízes e a parte aérea foram secas, separadamente, em estufa de circulação forçada de ar (a 650C por 72 horas) e em seguida determinada a massa seca e teores de P, K e S. A inoculação com fungos micorrízicos, principalmente o isolado de Rhizophagus clarus e o inóculo de Campos, proporcionou maior crescimento e maior aquisição em relação a K e S das mudas de teca. A inoculação com os fungos micorrízicos proporcionou maior eficiência de utilização de nutrientes.

ABSTRACT Symbiotic associations between tree species and mycorrhizal fungi may lead to better growth and nutrition of seedlings and so it becomes an important alternative to the establishment in the field, mainly in edaphic restriction areas, or to species of high nutritional demands. The cultivation of Tectona grandis (teca) in Brazil has been conducted in Cerrado areas with low fertility soils. The aim of the present study is to assess the effect of arbuscular mycorrhizal fungi (AMF) inoculation on the growth and mineral nutrition of teca seedlings. The experiment was performed in randomized blocks (six blocks), with four repetitions: 1) witness (inoculation-free mycorrhizal fungi); 2) inoculation with Rhizophagus clarus; 3) native AMF inoculum from twenty-year old teca cultivation in Mato Grosso state (MT inoculum); and 4) native AMF inoculum from clay extraction in Campos do Goytacazes (Campos inoculum). The plantlets were inoculated and cultivated in 6 dm³ pots for 135 days and assessed for stem hight and diameter of the stem base. Root samples were collected in order to assess the percentage of AMF colonization. The roots and the aerial part were dried, separately, in a forced air circulation oven at 65°C for 72 hours. Subsequently, the dry weight and the content of P, K AND S were determined. The mycorrhizal fungi inoculation, mainly the Rhizophagus clarus isolate and the Campos inoculum, has promoted better growth and K and S acquisition by teca seedlings. The inoculation using mycorrhizal fungi allowed greater nutrient use efficiency.

RESUMO O objetivo deste trabalho foi caracterizar a capacidade de germinação e diversidade das espécies do banco de sementes de um fragmento de mata ciliar localizado na Estação Experimental da Empresa de Pesquisa Agropecuária do Estado do Rio de Janeiro (PESAGRO-RJ), em Itaocara - RJ e, com isso, avaliar o seu potencial para uso em técnicas de nucleação. Amostras de 0,25 m x 0,25 m x 0,05 m de solo e serapilheira foram coletadas em cinco diferentes pontos do fragmento, a cada 10 m, a partir da margem do rio Paraíba do Sul. Em cada distância foram tomadas três amostras de solo e três amostras de solo + serapilheira. O material coletado foi levado à Universidade Estadual do Norte Fluminense (UENF) e disposto em bandejas plásticas de 25 cm de diâmetro e 9 cm de altura, em casa de vegetação. Os tratamentos foram dispostos em delineamento inteiramente casualizado (DIC) e comparados pelo teste de F (5%), com 15 repetições por tratamento, constituídas por uma bandeja. Durante um período de quatro meses, foram registrados 473 indivíduos, distribuídos entre herbáceos, arbustivos e arbóreos. O banco de sementes avaliado é composto, em sua maioria, por espécies herbáceas, destacando-se a Pteridium arachnoideum, com 58 indivíduos. Dentre as espécies arbustivas e arbóreas, destacaram-se Piper sp. e Trema micrantha, com 56 e 32 indivíduos, respectivamente. O banco de sementes do solo, juntamente com a serapilheira, apresentou menor número de espécies, sem diferença no número de indivíduos. Tanto o solo, quanto o solo com serapilheira apresentam potencial para uso em técnicas de nucleação.

ABSTRACT The objective of this study was to characterize the germination and species diversity of the seed bank of a fragment of riparian forest located at the Experimental Station of PESAGRO-RJ, in Itaocara city, RJ state, and evaluate its potential use in nucleation techniques. Samples of soil and soil + litter were removed with iron corer (0.25 mx 0.25 mx 0.05 m), at five different points of the fragment, each 10 m from the bank of Paraiba do Sul river. At each point three soil samples and three samples of soil + litter were collected. The material was made to UENF and arranged in plastic trays (25 cm in diameter and 9 cm tall) in the greenhouse. The treatments were arranged in randomized and compared by F test (5%), with 15 replicates of each treatment, represented by a tray. For four months, 473 individuals distributed among herbaceous, shrub and tree species were recorded. The seed bank is composed mostly of herbaceous species, highlighting the Pteridium arachnoideum (Kaulf.) Maxon, with 58 seedlings germinated. Among the shrub and tree species, the highlights Piper sp. and Trema micrantha (L.), with 56 and 32 seedlings germinated, respectively. The seed bank in the soil + litter, had a lower number of species, with no difference in the number of seedlings germinated. Both the soil and soil + litter have potential for use in nucleation techniques.

O objetivo deste trabalho foi avaliar o efeito do tipo de miniestacas e a necessidade de aplicação de ácido indolbutírico sobre o enraizamento e qualidade das mudas formadas de Handroanthus heptaphyllus. As miniestacas apicais e intermediárias foram obtidas em minijardim multiclonal formado a partir de sementes. As miniestacas foram preparadas com 5 cm de comprimento, um par de folhas reduzidas a 50% da área foliar e estaqueadas sem e com AIB na concentração de 8000 mg L-1. As avaliações foram realizadas aos 30 dias, na expedição do setor de enraizamento e aos 120 dias, quando a muda se encontrava formada. O experimento foi conduzido em delineamento inteiramente casualizado, em esquema fatorial 3 x 2 x 2 (três épocas de coleta, duas concentrações de AIB e duas posições do propágulo), com quatro repetições, sendo 12 miniestacas por repetição. De acordo com os resultados, o AIB não foi necessário para o enraizamento das miniestacas, entretanto, sua utilização promove incremento do número e comprimento de raízes. As miniestacas intermediárias proporcionaram maior massa seca de raízes aos 30 dias após o estaqueamento, e aos 120 dias, maior número de folhas e de raízes. A época de coleta influenciou a qualidade final das mudas. Aquelas produzidas na última coleta (oitavo) apresentaram valores médios inferiores nas características biométricas, exceto para o comprimento e número de raízes de primeira ordem.

The objective of this study was to evaluate the effect of type of cuttings and the need for application of IBA on rooting and quality of the seedlings formed Handroanthus heptaphyllus. The apical and intermediate cuttings were obtained in multiclonal minigarden formed from seeds. The cuttings were prepared with 5 cm length, a pair of leaves reduced to 50% of leaf area without staked and IBA at a concentration of 8000 mg L-1. Evaluations were performed at 30 days, the expedition rooting sector and at 120 days, when the change was in formed. The experiment was conducted in a completely randomized design in a factorial 3 x 2 x 2 (three sampling times, two concentrations of IBA and two positions of propagules), with four replications, with 12 cuttings per replicate. According to the results, the IBA was not necessary for the rooting of the shoots, however, their use promotes an increase in the number and length of roots. The intermediate cuttings showed higher dry mass of roots at 30 days after striking, and at 120 days, more leaves and roots. The collection time influenced the final quality of the seedlings. Those produced in the last collection (eighth) had lower mean scores in biometric characteristics, except for the length and number of roots of the first order.

A Handroanthus heptaphyllus Mattos, conhecida popularmente como ipê-roxo, é propagada comumente por via seminal, no entanto, suas sementes quando armazenadas, perdem rapidamente o poder germinativo, sendo assim, uma alternativa de propagação para esta espécie é a propagação vegetativa, técnica que favorece a produção de mudas em escala comercial, além de possibilitar ganho de características esperadas como uniformidade da muda no viveiro. O objetivo deste trabalho foi avaliar o efeito de diferentes concentrações de ácido indol-3-butírico (AIB) no enraizamento de miniestacas apicais de ipê-roxo. As miniestacas foram provenientes da primeira coleta de brotações das minicepas do minijardim multiclonal conduzido em tubetes realizada aos 231 dias após a germinação. Após a coleta, as miniestacas foram submetidas a cinco concentrações de AIB (0; 2000; 4000, 6000 e 8000 mg L-1) e em seguida foram estaqueadas em tubetes contendo Basaplant Florestal(r) e adubo de liberação lenta (Osmocote(r) 14-14-14). O experimento foi conduzido em delineamento inteiramente casualizado, com quatro repetições, compostas por dez miniestacas. Aos 30 dias, as miniestacas foram avaliadas quanto à sobrevivência, número de raízes de primeira e segunda ordem, comprimento das raízes de primeira ordem e massa seca do sistema radicular. Ao final do ciclo de produção, aos quatro meses, as mudas foram avaliadas quanto à altura, diâmetro do coleto, número de folhas, área foliar, massa seca da parte aérea, número e comprimento das raízes primárias e massa seca do sistema radicular. Observou-se mais de 95% de sobrevivência das miniestacas, aos 30 dias, em todos os tratamentos, com 80% delas enraizadas na ausência do fitorregulador. No entanto, o número de raiz de segunda ordem foi maior nas mudas submetidas a 8000 mg L-1. A utilização de AIB em miniestacas de ipê-roxo não é um condicionante para o enraizamento, embora tenha resultado em mudas com maior comprimento de raízes de primeira ordem e número de raízes de segunda ordem na concentração de 8000 mg L-1.

The Handroanthus heptaphyllus Mattos know as "ipê-roxo" is usually propagated by seeds. An propagation alternative for species. Is the vegetative propagation, technique that stimulates seedling production on a commercial scale besides the expected gain in characteristic as the uniformity of seedlings in the nursery. The objective of this work was the evaluation the effect of different concentrations of indol-3-butiric acid (AIB) on the apical minicutting rooting of this species. The cuttings were collected from the first ministumps shoots of the minigarden conducted in tubes, 231 days after germination. After the collect the minicuttings were submitted to five AIB concentrations (0; 2,000; 4,000; 6,000 and 8,000 mg L-1). Then were planted in tubes with Basaplant Forest(r) substrate and slow release fertilizer (Osmocote(r) 14-14-14). The experiment was carried out in a completely randonmized design with four replicates constituted by ten minicuttings. At 30 days the minicuttings were evaluated about survival, number of roots of the first and second orders, length of first order root and dry mass of the root system. At four months the cuttings were evaluated in height, root-collar diameter, number of leaves, leaf area, stem dry weight, number and length of first order roots and root dry weight. More than 95% survival the minicuttings was observed at 30 days in all treatments, and 80% of them rooted without IBA. However, the number of the second order roots was higher in cuttings submitted to 8,000 mg L-1. The use of IBA is not a condition for rooting of H. heptaphyllus cuttings, although it results in seedlings with longer roots of the first order and number of roots of the second order in the concentration of 8000 mg L-1.

RESUMO A redução do ganho em biomassa de lenho em árvores tem sido atribuída à ocorrência de deformações radiculares ainda na fase de viveiro. O objetivo deste trabalho foi avaliar a condutividade hidráulica do sistema radicular, trocas gasosas e a eficiência fotoquímica de mudas clonais de eucalipto com e sem indução de deformações radiculares. Os tratamentos foram: 1 - mudas sem a indução de deformações radiculares (produzidas de acordo com metodologia operacional do viveiro da Fibria Celulose S.A.) e 2 - mudas com indução de deformações radiculares. A indução da deformação radicular não resultou em queda no volume radicular. Contudo, deformações radiculares provocaram redução na condutividade hidráulica do sistema radicular, assim como foram verificadas quedas na taxa fotossintética das mudas ao longo do dia. A queda da taxa fotossintética em mudas com indução de deformações radiculares está associada a fatores estomáticos e não estomáticos.

ABSTRACT The gain reduction of wood biomass in trees has been assigned to root deformations even in the nursery phase. The objective of this work was the evaluation of the root system hydraulic conductivity, gas exchanges and photochemical efficiency of eucalypt clonal cuttings with and without root deformation inductions. The treatments were: 1) operational cuttings without root malformation inductions (grown according to the used methodology of Fibria Cellulose S.A.); 2) root deformation inductions. These inductions did not promote decrease in the root volume. However, the deformations brought reduction of the root system hydraulic conductivity. Lower photosynthetic rates were also observed along the day in the cuttings in the root deformed cuttings. This decreasing rate is connected to stomatal and non stomatal factors.