ABSTRACT: Appropriate management of factors that influence forest development is essential to increase yield of forest plantations. The objective of this study was to evaluate the influence of water seasonality, nutritional management, and uniformity on yield of eucalyptus plantations and estimate the potential, attainable, and observed yield of adult eucalyptus stands. We evaluated Eucalyptus clonal stands in six regions of Minas Gerais State, Brazil, in a system of first and second rotation across four age classes using the twin-plots method (TP). In the study, 142 TPs were allocated alongside 142 plots in a continuous forest inventory (CFI) network of a private enterprise. The CFI received operational fertilization and additional fertilization was carried out in the TP. The trees were measured at the beginning of the experiment and at every six months to quantify the production in the wet (PW) and dry (PD) periods of the year. Uniformity of plantations was evaluated using Pvar 50 % and the optimal uniformity index. Potential, attainable, and observed yields were estimated using the average annual increase at seven years of age. The PW showed higher plant yield. There was an effect due to water availability and nutrient level on the yield of the stands. The driest semester of the year produces approximately 30 % of the current annual increase. The stands under the second rotation tend to have less uniformity than the in the first rotation. Potential yield varied depending on rainfall intensity where wetter regions had the highest yield.

ABSTRACT: Leaf hyperspectral reflectance has been used to estimate nutrient concentrations in plants in narrow bands of the electromagnetic spectrum. The aim of this study was to estimate leaf nutrient concentrations using leaf hyperspectral reflectance and verify the variable selection methods using the partial least squares regression (PLSR). Two studies were carried out using stands with Eucalyptus clones. Study I was established in Eucalyptus stands with three clones, classifying leaves into five colour patterns using the Munsell chart for plant tissues. Immediately after leaf collection, leaf reflectance was read and the chemical analysis was performed. Study II was carried out in commercial clonal stands of Eucalyptus performing the same leaf sampling and chemical analysis as used in Study I. All leaf reflectance spectra were smoothed and three more pre-processing procedures were applied. In addition, three methods of PLSR were tested. The first derivative was more accurate for predicting nitrogen ( R c v 2 = 0.95), phosphorous ( R c v 2 = 0.93), and sulphur concentration ( R c v 2 = 0.85). The estimates for concentrations of calcium ( R c v 2 = 0.81), magnesium ( R c v 2 = 0.22), and potassium ( R c v 2 = 0.76) were more accurate using the logarithm transformation. Only the estimates for iron concentrations were performed with higher accuracy ( R c v 2 = 0.35) using the smoothed reflectance. The copper concentrations were more accurate ( R c v 2 = 0.78) using the logarithm transformation. Concentrations of boron ( R c v 2 = 0.68) and manganese ( R c v 2 = 0.79) were more accurate using the first derivative, while zinc ( R c v 2 = 0.31) concentration was most accurate using the second derivative.

ABSTRACT Determination of leaf nutrient concentrations is traditionally performed by carrying out destructive procedures, requiring laboratory chemical analysis, specialized equipment, and skilled labor. However, technological advances in recent years have now made it possible to analyze leaf nutrient concentrations using non-destructive methods such as leaf reflectance. This study evaluates the relationship between leaf reflectance and nutrient concentration in order to develop and apply nutrient indices by proximal sensing data in plantations of Eucalyptus. Two experiments were carried out for the development, application and validation of nutrient indices in Eucalyptus stands in the municipalities of Lassance and Três Marias, Minas Gerais state, Brazil. Study I was undertaken in Eucalyptus stands with 25 months old and, three clones. Leaves from the lower crown were visually classified into five color patterns using the Munsell chart for plant tissues. Study II was carried out in commercial stands of a hybrid of Eucalyptus urophylla ST Blake, whith 9, 12, 15 and 25 months old. Analysis revealed strong relationships between leaf nutrients and leaf reflectance in the visible and near infrared regions (400 - 900 nm) of the light spectrum. Correlation analysis between leaf reflectance and nutrients can be useful in an exploratory analysis of leaf nutrient concentration. Some nutrient indices developed (NI, PI, SI and CuI) provided satisfactory estimates of leaf nutrient concentration in Eucalyptus stands. The nutrient indices developed in this study may be a useful alternative to laboratory chemical analysis.

ABSTRACT The objective of this work was to evaluate the effects of fertilization, spatial arrangement and age on the biomass production in eucalyptus. The experiment was set up in a randomized block design with four replicates. Overall, 15 fertilizations adopted by forest companies in plots were evaluated, and two arrangements, 3.0 x 3.0 m and 6.0 x 1.5 m, were tested in subplots. Diameter at 1.30 m and total height were measured at 12, 24, 36, 48 and 60 months after planting to estimate trunk biomass. Dependence between commercial fertilization and arrangement were observed for trunk biomass. The biomass production rate in treatments where higher amounts of nutrients were applied decreased from the second year. The 3.0 x 3.0 m arrangement proved to be the most attractive option at 60 months using treatment with 2000 kg of agrosilicon, 400 kg of reactive phosphate, 130 kg of 04:26:16 + 0.5% Cu + 0.5% Zn and 150 kg of KCl + 1% B.

RESUMO Conhecer o tempo ótimo de enraizamento de miniestacas reduz o potencial de doenças e otimiza a utilização da casa de vegetação e de sombra. O objetivo do presente trabalho foi determinar o período de enraizamento das miniestacas de clone híbrido de Eucalyptus urophylla S.T. Blake e Eucalyptus grandis W. Hill ex Maiden na casa de vegetação e de sombra provenientes de minicepas submetidas a diferentes lâminas de irrigação aplicadas em minijardim e com e sem redução foliar da miniestaca. O experimento foi conduzido no viveiro da Empresa Sada Bio-Energia e Agricultura Ltda., Sete Lagoas-MG. O experimento foi instalado em delineamento em blocos casualizados no arranjo fatorial, composto por sete lâminas de irrigação e com e sem redução foliar. Os tratamentos foram definidos de acordo com a leitura diária do tanque Classe A (T1 = 50% da ET0 - frequência única; T2 = 75% da ET0 - duas vezes ao dia; T3 = 100% da ET0 - duas vezes ao dia; T4 = 125% da ET0 - três vezes ao dia; T5 = 150% da ET0 - três vezes ao dia; T6 = 100% da ET0 - frequência única e T7- operacional da empresa - lâmina 10,66 mm dia-1, fertirrigação oito vezes ao dia, durante cinco minutos com uma vazão de 0,8 L h-1). Foram avaliadas nas idades de 10, 20, 30, 40 e 50 dias, as variáveis massa seca da parte aérea, radicular e total. A lâmina de 2,19 mm dia-1 (T2) sem redução foliar apresentou menor tempo de enraizamento. O tratamento sem redução foliar proporcionou minimização do tempo de enraizamento para todas as lâminas de irrigação.

ABSTRACT Knowing the rooting optimum time reduces the potential for diseases and optimizes the use of greenhouse and shade. The aim of this study was to determine rooting period of the hybrid clone of cuttings of Eucalyptus urophylla S.T. Blake and Eucalyptus grandis W. Hill ex Maiden in the greenhouse and shade from different water irrigation level managements applied in minigardens and with two levels of foliar reduction in the minicuttings. The experiment was conducted in the nursery of the Sada Bio Energy and Agriculture Company, Sete Lagoas, Minas Gerais state, Brazil. The experiment was conducted in a randomized block design in factorial arrangement, consisting of seven irrigation management and reduced levels of two leaves (with and without reduction). The treatments were defined according to the daily reading of the Class A tank (T1 = 50% ET0 - single frequency, T2 = 75% ET0 - twice a day, T3 = 100% ET0 - twice a day, T4 = 125% ET0 - three times a day, T5 = 150% ET0 - three times a day, T6 = 100% ET0 - often single-T7 and the company operating Blade - 10.66 mm day-1, eight fertirrigation times a day for five minutes with a flow rate of 0.8 l h-1). They were assessed at ages 10, 20, 30, 40 and 50 days, the variables dry mass of minicuttings, root and total. The water irrigation level 2.19 mm / day-1 (T2) without foliar reduction showed the shortest the rooting time. The treatment without foliar reduction provided the minimizing of rooting time for all irrigation level managements (blades).

RESUMO A Amostragem Não Destrutiva (AND) permite uma caracterização eficiente, simples e segura das propriedades químicas do vegetal, como o Coeficiente de Utilização Biológico (CUB). A associação da AND com a técnica de Redes Neurais Artificiais (RNA) pode ser uma alternativa potencial em substituição às equações de regressão e aos métodos tradicionais de interpolação. Portanto, o presente trabalho objetivou avaliar a eficiência da RNA e da amostragem não destrutiva para estimar a eficiência de uso de nutrientes no tronco. O experimento foi instalado em blocos ao acaso, sendo estudado, em três blocos, o efeito de cinco espaçamentos de plantio: T1 - 3,0 m x 0,5 m; T2 - 3,0 m x 1,0 m; T3 - 3,0 m x 1,5 m; T4 - 3,0 m x 2,0 m e T5 - 3,0 m x 3,0 m. Uma árvore-amostra foi abatida para realizar a cubagem rigorosa e quantificar a matéria seca de casca e lenho por unidade experimental, totalizando-se 15 árvores. As árvores-amostras foram pesadas no campo e subamostras de casca e lenho foram coletadas ao longo do fuste para compor uma amostra composta por árvore. Também foi retirada uma amostra simples de cada componente obtidas com auxílio de um formão e martelo na região do DAP nas mesmas árvores-amostras. As amostras foram secas a 65ºC até peso constante. O material vegetal foi moído e submetido à análise química. Ajustaram-se modelos de regressão e aplicação de RNA para estimação do CUBTronco a partir do CUBDAP Casca e CUBDAP Lenho. As RNA apresentaram maior precisão e confiabilidade do que a regressão. A modelagem por redes neurais artificiais utilizando-se apenas uma amostra da casca na região do DAP demonstrou ser adequada para a estimativa do coeficiente de utilização biológico do tronco.

ABSTRACT The Non-Destructive Sampling (NDS) provides an efficient, simple and safe characterization of chemical properties of the plant, as the Coefficient of Biological Use (CBU). The association of NDS with the technique of Artificial Neural Networks (ANN) can be a potential alternative to replace the regression equations and the traditional methods of interpolation. Therefore, this work aimed to evaluate the efficiency of ANN and non-destructive sampling for the efficiency of nutrient use in the trunk. The research plot was installed in a randomized block being studied, in three blocks, the effect of five planting spacing: T1-3,0m x 0,5 m, T2 - 3,0 m x 1,0 m, T3 - 3,0 m x 1,5 m, T4 - 3,0 m x 2,0 m e T5 - 3,0 m x 3,0 m. A sample-tree was felled to make the cubage and quantify the dry bark and wood per experimental plot, totaling 15 trees. The sample-trees were weighed in the field and subsamples of bark and wood were collected along the stem to form a composite sample per tree. Also removed was a single sample of each component obtained with the aid of a chisel and hammer in DBH in the same sample-trees. The samples were dried at 65°C until constant weight. The material was ground and subjected chemical analysis. Adjusted regression models and application of ANN to estimation of CBUTrunk from the CBUDBH Bark and CBUDBH Wood. The ANN had a higher accuracy and reliability of the regression. Modeling by artificial neural networks using only sample in the DBH region proved to be adequate for estimating the coefficient of biological use of stem.

ABSTRACT Nitrogen (N) has commonly been applied in Eucalyptus stands in Brazil and it has a direct relation with biomass production and chlorophyll content. Foliar N concentrations are used to diagnose soil and plant fertility levels and to develop N fertilizer application rates. Normally, foliar N is obtained using destructive methods, but indirect analyses using Vegetation Indexes (VIs) may be possible. The aim of this work was to evaluate VIs to estimate foliar N concentration in three Eucalyptus clones. Lower crown leaves of three clonal Eucalyptus plantations (25 months old) were classified into five color patterns using the Munsell Plant Tissue Color Chart. For each color, N concentration was determined by the Kjeldahl method and foliar reflectance was measured using a CI-710 Miniature Leaf Spectrometer. Foliar reflectance data were used to obtain the VIs and the VIs were used to estimate N concentrations. In the visible region, the relationship between N concentration and reflectance percentage was negative. The highest correlations between VIs and N concentrations were obtained by the Inflection Point Position (IPP, r = 0.97), Normalized Difference Red-Edge (reNDVI, r = 0.97) and Modified Red-Edge Normalized Difference Vegetation Index (mNDI, r = 0.97). Vegetation indexes on the red edge region provided the most accurate estimates of foliar N concentration. The reNDVI index provided the best N concentration estimates in leaves of different colors of Eucalyptus urophylla × grandis and Eucalyptus urophylla × urophylla (R2 = 0.97 and RMSE = 0.91 g kg−1).

O gênero Hymenaea pertence à família Leguminosae, subfamília Caesalpinoideae, com nome popular de jatobá. No gênero Hymenaea, foram descritas aproximadamente 25 espécies. Já no Brasil, verifica-se a presença de 13 espécies, com destaque para a Hymenaea martiana Hayne e a Hymenaea courbaril Linneaus. Na literatura, há vários trabalhos que tratam principalmente da quebra de dormência das sementes e da produção de mudas, sobretudo da espécie Hymenaea courbaril Linneaus, porém essas avaliações por matriz ainda são incipientes. Este trabalho teve por objetivo avaliar e comparar a germinação e o crescimento inicial de mudas entre as espécies e as matrizes de Hymenaea martiana Hayne e Hymenaea courbaril Linneaus. Foram desenvolvidos dois experimentos: o primeiro avaliou a germinação, e o segundo, o crescimento inicial de mudas. As duas espécies avaliadas apresentaram comportamentos distintos entre a germinação e o crescimento inicial das mudas, sendo a Hymenaea courbaril Linneaus a espécie com maior média para ambas variáveis, porém não apresentou variabilidade fenotípica entre matrizes.

The Hymenaea genus belongs to the family Leguminosae, subfamily Caesalpinoideae with the common name jatobá. Approximately 25 species have been described in the genus Hymenaea and 13 of them are present in Brazil. Among them we can highlight the species Hymenaea martiana Hayne and Hymenaea courbaril Linneaus. In literature, there are several studies dealing mainly the dormancy breakage and the seedling production, mainly with Hymenaea coubaril Linneaus, but these reviews per matrices are incipient. This study aimed to evaluate and compare the germination and seedling growth between species and between matrices of the Hymenaea martiana Hayne and Hymenaea courbaril Linneaus. Two experiments were conducted: the first evaluated the germination and the second the seedlings growth. The two species studied showed different behavior between germination and the seedling growth, with Hymenaea courbaril Linneaus showing the greatest average for both variables. However, this did not show phenotypic variability between matrices.

O objetivo deste estudo foi avaliar o efeito da redução foliar no enraizamento de dois tipos (apicais e intermediárias) de miniestacas e microestacas de quatro clones híbridos de Eucalyptus globulus. Foram realizadas avaliações quanto ao percentual de sobrevivência, raízes emitidas na extremidade inferior do tubete, enraizamento, altura, diâmetro do colo e massa seca da parte aérea e da raiz. Aos 90 dias de idade, pôde-se concluir que as estacas apicais sem e com redução foliar foram superiores às intermediárias e os clones se comportaram de maneira diferenciada em relação ao enraizamento das miniestacas e microestacas. A propagação vegetativa por estacas apicais sem redução foliar pode ser recomendada para a produção de mudas de Eucalyptus urophylla x E. globuluse de Eucalyptus grandis x E. globulus.

The objective of this study was to evaluate the effect of leaf reduction in the rooting of two types of mini-cuttings and micro-cuttings (apical and intermediate) of four hybrid clones of Eucalyptus globulus. Evaluations were performed on the percentage of survival, roots at the lower end of the tube, rooting, height, stem diameter, dry weight of shoot and root. At 90 days, it can be concluded that the apical cuttings with and without leaf reduction were higher than the intermediate cuttings, besides each clone behaved differently in relation to the rooting of mini-cuttungs and micro-cuttings. Vegetative propagation by apical cuttings without leaf reduction can be recommended for the production of seedlings of Eucalyptus urophylla x E. globulus and Eucalyptus grandis x E. globulus.

O rápido crescimento inicial das mudas é um ponto crítico para o sucesso da plantação florestal. Neste estudo, objetivou-se avaliar a influência da idade e do volume de substrato utilizado na produção de mudas clonais de Eucalyptus urograndis no desempenho após o replantio. O experimento foi conduzido em blocos casualizados com dez repetições, no arranjo fatorial 2 x 4 (mudas clonais produzidas em tubetes de 53 e 180 cm³ e com quatro idades - 60, 75, 90, e 120 dias) no espaçamento 3 x 3,33 m. Como tratamento adicional, avaliaram-se plantas de um plantio comercial, plantadas 20 dias antes da instalação do experimento. A utilização de mudas para replantio produzidas com maior volume de substrato possibilitou melhor crescimento inicial em campo. Entretanto, aos 12 meses de idade, o crescimento das mudas de replantio não foi influenciado pela idade e nem pelo volume de substrato utilizado para a produção das mudas.

Rapid early growth of tree seedlings is critical for the forest plantation success. This study aimed to evaluate the influence of age and substrate volume on the clonal eucalypt seedlings performance after replanting. The experiment was conducted in randomized blocks with ten replications in a 2 x 4 factorial arrangement (clonal seedlings grown in tubes of 53 and 180 cm³ and four ages - 60, 75, 90 and 120 days) in a 3 x 3,33 m spacing. As an additional treatment, it was evaluated plants of a commercial plantation, settled 20 days before the experiment. Seedling replanting with higher substrate volume provided better initial growth in the field. However, at 12 months of age, replanting seedling growth was not influenced by age or by the amount of substrate used for seedling production.

Este estudo teve por objetivo avaliar a influência de diferentes padrões de miniestacas no enraizamento e produção de mudas do híbrido do Eucalyptus grandis Hill x E. urophylla S.T. Black no verão e no inverno. Experimentos com cinco clones e 12 diferentes padrões de miniestacas foram conduzidos em duas épocas do ano (verão e inverno). A sobrevivência e enraizamento das miniestacas foram avaliados na saída da casa de vegetação e na saída da casa de sombra e, a pleno sol, a sobrevivência, a altura, o diâmetro do colo, o peso de massa seca da parte aérea e o da raiz. Os resultados indicaram que a manutenção das folhas é importante para o enraizamento de miniestacas de Eucalyptus grandis x E. urophylla, e as folhas basais obtiveram maiores valores de enraizamento. Mudas produzidas no verão, utilizando miniestacas de 10 cm de tamanho, tiveram maior crescimento. A metodologia de não redução das folhas mostrou-se procedimento adequado para produção de mudas nas duas épocas do ano.

The present study aimed to evaluate the influence of different patterns of mini-cuttigs on rooting and production of hybrid Eucalyptus grandis Hill x E. urophylla S. T. Black hybrid in summer and winter. Experiments with five clones and 12 different patterns of mini-cuttings were conducted in two seasons (summer and winter). The survival and rooting were evaluated ate the output greenhouse and output of the shade and in full sun, survival, height, diameter, the dry weight of shoot and root. The results indicated that the maintenance of leaves is important for rooting mini-cuttings of Eucalyptus grandis Hill x E. urophylla S. T. Black hybrids, and the basal leaves had higher values of rooting. Seedlings produced in summer, using cuttings of 10 cm in size, had higher growth's methodology leaves no reduction procedure proved suitable for seedling production in both seasons.

O objetivo deste trabalho foi avaliar o uso de reguladores de crescimento, aditivos antioxidantes, tipo de explantes e intensidade de cobertura de mudas aclimatizadas, na micropropagação de sucupira-preta (Bowdichia virgilioides) por meio de gemas axilares. Os explantes foram cultivados para a multiplicação em meio de cultura básico WPM, suplementado com concentrações de benzilaminopurina (BAP). No alongamento, os tratamentos foram combinações de ácido naftalenoacético (ANA) e BAP adicionadas ao meio. Para o enraizamento, as brotações foram colocadas em meio com concentrações de ácido indolbutírico, ou em meio com combinações dos aditivos polivinilpirrolidona e carvão ativado, em diferentes concentrações de ANA. As plantas foram transplantadas para copos de plástico, com substrato, e cobertas com saco de polietileno. Posteriormente, esses sacos foram retirados, ou perfurados, ou não retirados, o que constituiu os tratamentos de pré-aclimatização in vitro. A aclimatização ex vitro foi realizada após o período de pré-aclimatização in vitro. A sucupira-preta apresentou melhor micropropagação com emprego de: segmentos cotiledonares e 0,3 mg L-1 de BAP, na multiplicação; 0,3 mg L-1 de ANA e 0,03 mg L-1 de BAP, no alongamento; e carvão ativado (2,0 mg L-1), no enraizamento e na pré-aclimatização in vitro, com uso de cobertura de plástico transparente em torno da muda.

The objective of this work was to evaluate the use of growth regulators, antioxidant additives, type of explants, and coverage intensity of acclimatized seedlings in the micropropagation of sucupira-preta (Bowdichia virgilioides) through axillary buds. Explants were cultured for multiplication on WPM medium, supplemented with concentrations of benzylaminopurine (BAP). In the elongation phase, treatments consisted of naphthaleneacetic acid (NAA) and BAP combinations added to the medium. For rooting, shoots were inoculated in medium containing concentrations of indolbutyric acid or combinations of the additives polyvinylpyrrolidone and charcoal, in different NAA concentrations. Plants were transplanted to plastic cups with substrate, and covered with polyethylene bags. Later, the bags were withdrawn, or perforated, or not withdrawn, which constituted the in vitro pre-acclimatization treatments. Ex vitro acclimatization was carried out after the period of in vitro pre-acclimatization. Sucupira-preta had the best micropropagation using: cotyledon segments and 0.3 mg L-1 BAP, for multiplication; 0.3 mg L-1 NAA and 0.03 mg L-1 BAP, for elongation; and 2,0 mg L-1 activated carbon for rooting and for the in vitro pre-acclimatization, with the use of a transparent plastic cover around seedling.

O objetivo deste trabalho foi estimar a produção de madeira e biomassa, bem como a quantidade de nutrientes acumulada, em povoamento de eucalipto submetido a intensidades de desbaste e à fertilização pós-desbaste. O experimento foi realizado em blocos ao acaso, em parcelas subdividas, com duas repetições dos tratamentos dentro de cada bloco. Nas parcelas, foram avaliadas quatro intensidades de desbaste (0, 20, 35 e 50%) e, nas subparcelas, as condições com e sem fertilização pós-desbaste. O desbaste foi realizado aos 89 meses e a aplicação da fertilização aos 99 meses. Os dados foram coletados aos 125 meses. O desbaste influenciou o crescimento em diâmetro, área basal, volume de madeira e biomassa. A fertilização pós-desbaste não afetou o acúmulo de nutrientes pelo povoamento nem sua produção. O acúmulo de nutrientes na parte aérea e no tronco foi inversamente proporcional à intensidade dos desbastes. O conteúdo de Ca na serapilheira variou de acordo com os desbastes, e o de K, Ca, Mg e S de acordo com a fertilização. O desbaste tem maior influência do que a fertilização na produção florestal pós-desbaste.

The objective of this work was to estimate the production of wood and biomass, as well as nutrient accumulation, in a eucalyptus plantation subjected to thinning intensities and post-thinning fertilization. The experiment was carried out in randomized blocks, in a split-plot arrangement, with two replicates of treatments within each block. Thinning intensities (0, 20, 35, and 50%) were evaluated in the plots, and the fertilized and non-fertilized conditions in the split plots. Thinning was done at 89 months, and the fertilizer application at 99 months. Data were collected at 125 months. Thinning affected the diameter growth, basal area, wood volume, and biomass. Post-thinning fertilization did not affect nutrient accumulation by the forest, neither its production. Nutrient accumulation above ground and in the trunks was inversely proportional to thinning intensity. Calcium content in the litter varied with thinning, and the ones of K, Ca, Mg, and S, with fertilization. Thinning has a higher influence on forest post-thinning production than fertilization.

RESUMO O estado nutricional da planta-matriz é de grande importância para a manutenção do seu vigor vegetativo, o que determina a produção de brotos e também os índices de enraizamento e velocidade de formação das raízes, uma vez que os macronutrientes e os micronutrientes estão envolvidos nos processos bioquímicos e fisiológicos vitais à planta. Nesse sentido, o objetivo deste trabalho foi avaliar a influência da adubação NPK sobre a partição de biomassa seca e nutriente em minicepa de eucalipto em solução nutritiva. O trabalho foi realizado de novembro de 2008 a janeiro de 2009, em casa de vegetação. Foi utilizado delineamento inteiramente casualizado em esquema fatorial fracionado (4x4x4)1/2, perfazendo 32 tratamentos com três repetições. Os tratamentos se constituíram de quatro doses dos nutrientes de N (50; 100; 200 e 400 mg L-1) na forma de ureia, P (7,5; 15; 30 e 60 mg L-1) na forma de ácido fosfórico e K (50; 100; 200 e 400 mg L-1) na forma de cloreto de potássio em solução nutritiva. Houve efeito significativo apenas para as doses de N isoladamente, para a biomassa seca das miniestacas e biomassa seca da parte aérea e raiz das minicepas com efeito linear decrescente, com o aumento das doses de N. A dose de 50 mg L-1 de N proporcionou maior acúmulo de biomassa seca das miniestacas e minicepas. A distribuição percentual da biomassa seca e dos nutrientes na biomassa seca das miniestacas, parte aérea e raízes das minicepas variou em relação às doses de N. A extração de macronutrientes pelas miniestacas de 6 cm na dose de 50 mg L-1 de N seguiu a seguinte ordem decrescente de N > S > P > K > Ca > Mg e micronutrientes de Cu > B > Mn > Fe > Zn.

ABSTRACT The nutritional status of the matrix plant has a great importance for the maintenance of its vegetative vigor, which determines the sprouts production and also the rooting percentage and the speed of root formation, since the macro and micronutrients are involved in biochemical and physiological vital processes for the plant. Thus, this study aimed to evaluate the influence of NPK fertilizer on dry biomass production by mini-cuttings and mini-stumps and the percentage distribution of nutrients in a simple hybrid plant of Eucalyptus urophylla in nutrient solution. The experiment was realized from November, 2008 to January, 2009 in a vegetation environment. The experimental design was a completely randomized in factorial scheme with a fractional factorial (4x4x4)1/2, adding up to 32 treatments with three replicates. The treatments consisted of four levels nutrients of nitrogen (50, 100, 200 and 400 mg L-1) in the urea form, P (7.5, 15, 30 and 60 mg L-1) in the phosphoric acid form and K (50, 100, 200 and 400 mg L-1) in the potassium chloride form, in the nutrient solution. There was significant effect only to the N doses to the dry mass of mini-cuttings and the dry mass of shoots and roots of mini-stumps with decreasing linear effect against N doses increasing. The doses of 50 mg.L-1 of N promoted higher accumulation of dry mass in mini-cuttings and mini-stumps. The percentage distribution of dry mass and of the nutrients in dry mass of mini-stumps, shoots and roots of mini-stumps varied in relation to N doses. Macronutrients extraction from mini-stumps of 6 cm at a dose of 50 mg L-1 of N followed the order of decreasing N > S > P > K > Ca > Mg and micronutrients Cu > B > Mn > Fe >Zn

O pequi é uma espécie com ampla distribuição no cerrado brasileiro, tendo grande importância social e econômica para os habitantes desse bioma. O presente trabalho foi proposto em função da ausência de informações sobre os efeitos de fatores genéticos e ambientais na expressão de variáveis físicas em frutos dessa espécie. Informações dessa natureza facilitam as decisões em relação ao processo de domesticação e melhoramento dessa espécie. Para atender a este objetivo, colheram-se frutos nos municípios de Curvelo e São Gonçalo do Rio Preto, Minas Gerais, totalizando 15 matrizes por município, selecionadas através de características que refletem suas idades, sendo a principal o diâmetro do tronco rente ao solo (DAS). As variáveis físicas avaliadas foram: Peso Total do Fruto (PTF); Peso do Mesocarpo Externo (PME); Peso dos Putamens (PTP) por fruto; Nº de Putamens (NP) por fruto e Peso Total de Polpa (PTPL) por fruto. O efeito de matrizes foi altamente significativo para todas as variáveis avaliadas, enquanto o de populações foi apenas para NP. As estimativas das correlações entre as variáveis avaliadas foram todas positivas, algumas significativas. As estimativas das correlações entre DAS e as demais variáveis também foram todas positivas, algumas significativas. Os resultados permitem concluir que: há grandes expectativas de ganhos a partir da propagação vegetativa de matrizes selecionadas no campo para as características físicas de seus frutos; o peso de polpa por fruto, caráter de grande importância econômica, mas de avaliação trabalhosa, pode ser selecionado a partir da avaliação do peso de putamens por fruto; o efeito da idade da planta sobre a expressão de variáveis físicas em frutos de pequi é nulo ou positivo, podendo a seleção ser conduzida em plantas jovens.

Pequi is a very common tree in Central and Center-East Brazilian territory, known as Cerrado sensu strict, and its fruits are largely appreciated by people that live in these regions. This study was proposed due to the lack of information about environmental and genetic effects on physical attributes expression in pequi fruits. Information on this subject is relevant to favor decisions regarding to domestication and breeding processes of this species. Pequi fruits were collected from populations of Curvelo and São Gonçalo do Rio Preto, State of Minas Gerais, being 15 mother trees per population. These mother trees were selected based on physical attributes that imply their age, being stem diameter at ground level (SD), the main one. Physical attributes were: fruit Total Weight (FTW); Outer Mesocarp Weight (OMW); Putamen Weight per fruit (PW); Putamen Number per fruit (PN) and Pulp Total Weight per fruit (PLTW). There was a mother tree effect for all attributes evaluated, whereas for populations, there was effect only for PN. Correlations among all variables were positive, being some of them significant. Also, correlations between SD and all other variables were positive and some, significant. Results allow the conclusion of high expected gains through vegetative propagation of mother tree selected by means physical fruit attributes: pulp weight can be selected based on putamen weight; the effect of plant age on fruit physical attributes is null or positive, so the selection can be carried out in youth plants.