Abstract Objective: Cognitive dysfunction may occur postoperatively. Fast and efficient assessment of Postoperative Cognitive Dysfunction (POCD) can minimize loss of quality of life, and therefore, a study comparing a digital game with standard neuropsychological tests to assess executive, mnemonic, and attention functions to evaluate POCD seems to be relevant both for research and clinical practice. Methods: A battery of standardized tests and a digital game (MentalPlus®) were administered to 60 patients at the Central Institute of Hospital das Clínicas in São Paulo (36 women and 24 men), with ages between 29 and 82 years, preand post-surgery performed under anesthesia. Correlation and linear regression model were used to compare the scores obtained from the standardized tests to the scores of the six executive and cognitive functions evaluated by the game (shortand long-term memory, selective and alternating attention, inhibitory control, and visual perception). Results: After correlation analysis, a statistically significant result was found mainly for the correlation between the scores from the phase of the digital game assessing the visuoperception function and the scores from the A and B cards of the Stroop Test (p < 0.001, r = 0.99 and r = 0.64, respectively), and the scores from TMTA (p = 0.0046, r = 0.51). We also found a moderate correlation between the phase of the game assessing short-memory function and VVLT (p < 0.001, r = 0.41). No statistically significant correlations were found for the other functions assessed. Conclusion: The digital game provided scores in agreement with standardized tests for evaluating visual perception and possibly short-term memory cognitive functions. Further studies are necessary to verify the correlation of other phases of the digital game with standardized tests assessing cognitive functions.

Abstract Chronic Lymphocytic Leukemia (CLL) has shown great biological heterogeneity, with a variable prognosis, and a short survival in some patients. In this light, the present study focused on the prognostic utility of circulating microparticles (MPs) and a Thrombin Generation (TG) Profile for thrombotic risk and disease progression in CLL patients. Circulating microparticles and TG were evaluated in 35 patients with CLL and 35 healthy individuals. For circulating microparticles, significant differences were observed among the following groups: MPs derived from endothelial cells (p = 0.002), B lymphocytes (p < 0.001), platelets (p = 0.003), and Tissue Factor MPs in monocytes (p < 0.001). In all cases, MP values were higher for the CLL group. When compared to the controls, CLL patients presented a decrease in TG, characterized by a reduced endogen thrombin potential (ETP) (p = 0.031). When the results were analyzed according to the Binet stage, as compared to the controls, the Binet B+C group also presented lower ETP values (p = 0.009). No significant differences were observed between the control and the Binet A groups or between the Binet A and the Binet B + C groups. Although hemostatic alterations may occur in patients with CLL, these parameters do not seem to be useful to indicate disease progression.

ABSTRACT: Proper plant nutrition is critical to increasing the yield of bananas. The objective was to establish the potential nutrient-response curves and sufficiency ranges using the boundary line approach (BLA) and the method proposed by Kenworthy (MK) to assess the nutritional status of ‘Prata-Anã’ bananas cultivated under two environmental conditions. The study was carried out using a database comprising leaf nutrient concentrations and banana yields grown at Missão Velha, Ceará, and Ponto Novo, Bahia, Brazil. The reference population consisted of high-yielding plants with yields greater than the mean yield plus 0.5 standard deviation. The database was divided into two datasets. One contained 253 leaf analysis results and a reference population with a mean yield greater than 39.81 t ha−1 yr−1 at Missão Velha. The other contained 147 samples and a reference population with a mean yield greater than 41.69 t ha−1 yr−1 at Ponto Novo. The sufficiency ranges obtained by the BLA for ‘Prata-Anã’ banana in Bahia and Ceará, respectively, are: a) for macronutrients (g kg−1): N (19.3-22.0) and (19.9-22.1); P (1.4-2.0) and (1.4-1.6); K (22.6-32.2) and (24.0-31.3); Ca (4.6-6.5) and (5.3-5.8); Mg (1.8-2.6) and (2.1-2.7); S (1.3-2.0) and (1.3-1.5); b) for micronutrients (mg kg−1): B (8.4-13.0) and (13.7-16.4); Cu (5.6-8.4) and (4.4-5.2); Fe (54.2-77.6) and (39.0-55.0); Mn (140.1-222.8) and (64.0-91.0); Zn (13.5-18.3) and (12.4-14.5). The sufficiency ranges obtained by the BLA are more assertive when assessing the nutritional status for ‘Prata-Anã’ banana.

ABSTRACT Tissue analysis results are interpreted by comparing them with nutrient standards; however, using universal standards may lead to a misleading nutritional diagnosis. This study aimed to evaluate the degree of universality of Kenworthy and DRIS norms for irrigated ‘Prata-Anã’ (AAB) and ‘Grande Naine’ (AAA) banana plants grown in two environments. The study was carried out using a database containing leaf nutrient contents and yield data of two farms located in Ponto Novo, Bahia State, and Missão Velha, Ceará State, Brazil. A reference population was that with yields above the average yield plus 0.5 standard deviation. Using a reference population, the mean, standard deviation, and coefficient of variation of nutrient content and dual nutrient ratios were calculated for each site × cultivar combination. To verify the homogeneity of variance among populations, F-test was used (p≤0.05). Means were compared using t-test (p≤0.05). Differences in climate and soil at each farm explain the high frequency of significant differences found between norms for each site. Kenworthy norms established for interpreting leaf nutrient contents of P, K, Ca, Mg, S, Cu, Fe, Mn, and Zn for ‘Prata-Anã’ grown in Ceará were higher than those in Bahia, while for N and B contents, the norms were higher in Bahia. This is due to differences in soil fertility and alkalinity affecting nutrient availability as well as non-nutritional factors. Kenworthy and DRIS norms for ‘Prata-Anã’ and ‘Grande Naine’ bananas grown in Ceará have higher variability and are greater than for those grown in Bahia. Norms are less convergent for ‘Prata-Anã’ than ‘Grande Naine’. Site- and cultivar-specific norms are recommended over universal ones for assessing the nutritional status of ‘Prata-Anã’ and ‘Grande Naine’ banana plants cultivated in different environments.

ABSTRACT Purpose: To compare biological compatibility, hemostasis, and adhesion formation between oxidized regenerated cellulose and lyophilized hydrolyzed porcine collagen in liver trauma. Methods: Forty male Wistar rats constituted two groups: group A (oxidized cellulose) and group B (lyophilized hydrolyzed collagen). Standardized liver trauma was made, and the hemostatic agent was applied. Animals in subgroups A7 and B7 were submitted to euthanasia and relaparotomy after seven days, and in subgroups A14 and B14 after 14 days. Macroscopic and microscopic results were evaluated. Results: There was no fluid in the cavity in any of the animals, and adhesions were present in all of them. In the analysis after seven days, the adhesions were grades 3 or 4 and consisted of omentum, small intestine, and abdominal wall (p<0.05). In both groups, the mesh was surrounded by a capsule, which was not observed after 14 days. In the evaluation after 14 days, adhesions were grades 2 or 3 (p>0.05). The microscopic examination showed subacute and chronic reactions, in both groups and in both timepoints, with similar frequency. The intensity of fibrosis always presented positive scores. Microabscesses and xanthomatous macrophages were observed in both groups. Conclusions: There was no superiority of one agent over the other.

Abstract Mitochondrial molecular markers (DNA sequences of D-loop, cytochrome b and cytochrome c oxidase I) were employed to characterize populations of the piranha Serrasalmus maculatus from Upper Paraná, Upper Paraguay and Tocantins River basins. D-loop sequences of S. maculatus population from Paraná-Paraguay River basin exhibited tandem repeats of short motifs (12 base pairs) and variable numbers depending on specimens, accounting for length variation. Concatenated mitochondrial sequences suggested that S. maculatus encompasses different mitochondrial DNA lineages. Although sampling was restricted to three river basins, phylogenetic analysis clearly indicated that the species currently recognized as S. maculatus presents high genetic variability. Maximum likelihood and Bayesian analysis clustered S. maculatus populations according to their locations. However, the highest genetic differentiation was identified between populations from Paraná-Paraguay system and Tocantins River basin. Three species delimitation analyses (PTP, GMYC, and ABGD) suggested that there are at least two species among the analyzed populations. The analysis of the mitochondrial sequences evidenced genetic differentiation among populations corresponding to related, but different species, suggesting that at least S. maculatus from the Tocantins River and Paraná-Paraguay River basins are most likely different species. Therefore, S. maculatus should be considered a species complex with morphologically cryptic diversity. An integrative revision is suggested.

ABSTRACT Natural ventilation micropropagation systems differ from conventional systems by allowing gas exchange between the internal and external media of the culture flask. The objective of this work was to compare the conventional system of in vitro propagation of Eugenia dysenterica (Mart.) DC. with a natural ventilation system. For shooting, explants were inoculated into test tubes with conventional lids and natural ventilation lids (NV), and WPM medium supplemented with four concentrations levels of 6-benzilaminopurine (BAP). The position of explants in each plant was considered by identifying buds as more proximate to the root, or to the apex, or in an intermediate position. Plant growth in the natural ventilation system was superior to that in the conventional system, with a 448.53% increase in leaf number, 85.64% increase in chlorophyll a levels and 74.90% increase in chlorophyll b levels. Plants with intermediate buds exhibited better results. Foliar anatomical analysis revealed abnormalities in leaves grown in the conventional system such as “giant” stomata, which remain always open. Our results indicate that the use of natural ventilation improves the water loss regulation capacity in micropropagated E. dysenterica plants and may favor plants survival and growth after transference to the natural environment.

RESUMO Racional: Pancreatectomia distal laparoscópica (PDL) é a abordagem de escolha para ressecção de tumores no pâncreas distal devido a suas muitas vantagens sobre a abordagem laparotômica. Objetivo: Analisar e comparar os resultados em curto e longo prazo da PDL realizada por meio de duas técnicas diferentes: com esplenectomia vs. preservação esplênica e preservação dos vasos esplênicos. Método: Cinquenta e oito pacientes foram operados e subsequentemente divididos em dois grupos: grupo 1, PDL com esplenectomia (PDLE) e grupo 2, PDL com preservação esplênica e dos vasos esplênicos (PDLPEVE). Resultados: As características epidemiológicas foram similares entre os dois grupos (idade, gênero, IMC e tamanho da lesão). Ambas as médias de tempo operatório (p=0,04) e de sangramento intraoperatório (p=0,03) foram maiores no grupo 1. A média de linfonodos ressecados também foi maior no grupo 1 (p<0.000). Não houve diferença em relação a conversão, morbidade ou mortalidade pós-operatória precoce. A média de internação hospitalar foi similar entre os grupos. Fístula pancreática (graus B e C) foi similar entre os grupos. A média de seguimento global foi 37,6 meses (5-96). Complicações tardias foram similares entre os grupos. Conclusão: Ambas as técnicas foram superponíveis, entretanto a PDLE apresentou respectivamente maiores sangramento intraoperatório, tempo cirúrgico e número de linfonodos ressecados. Não foram observadas diferenças de infecções ou neoplasias relacionadas com esplenectomia durante o período de seguimento. Manutenção do baço evitou imunizações periódicas na PDLPEVE. Ela pode ser indicada em lesões pancreáticas pequenas com curso indolente.

ABSTRACT Background: Laparoscopic distal pancreatectomy (LDP) is the preferred approach for resection of tumors in the distal pancreas because of its many advantages over the open approach. Aim: To analyse and compare short and long-term outcomes from LDP performed through two different techniques: with splenectomy vs. spleen preservation and splenic vessel preservation. Method: Fifty-eight patients were operated and subsequently divided between two groups: Group 1, LDP with splenectomy (LDPS); and Group 2, LDP with spleen preservation and preservation of splenic vessels (LDPSPPSV). Results: The epidemiological characteristics were statistically similar between the two groups (age, gender, BMI and lesion size). Both the mean of operative time (p=0.04) and the mean of intra-operative blood loss (p=0,03) were higher in Group 1. The mean of resected lymph nodes was also higher in Group 1 (p<0.000). There were no statistic differences between the groups in relation to open conversion, morbidity or early postoperative mortality. The mean hospital stay was similar between groups. Pancreatic fistula (grade B and C) was similar between the groups. The mean of overall follow-up was 37.6 months (5-96). Late complications were similar between the groups. Conclusion: Both techniques were superimposable; however, LDPS presented, respectively, higher intra-operative bleeding, longer duration of the operation and higher number of lymph nodes resected. No differences were observed in the studied period in relation to the appearance of infections or neoplasm related to splenectomy during follow-up. Maintenance of the spleen avoided periodic immunizations in patients in LDPSPSV. It is indicated in small pancreatic lesions with indolent course.

Abstract In cement production, which involves the production of cement clinker in rotary kilns, the main refractories used are magnesia-spinel bricks. These bricks may suffer infiltration by the clinker liquid phase, resulting in the corrosion of the spinel and the formation of low refractoriness mineralogical phases, such as the Q phase (C20A13M3S3), which compromises refractory performance. Thus, the aim of this work is to correlate the infiltration resistance of magnesia-spinel bricks made from different grades of magnesia by clinker collected in three different cement plants (A, B and C). The purity of magnesia, besides its physical properties, strongly influences the properties and the infiltration resistance of magnesia-spinel bricks; as such the use of high grade magnesia is essential for producing high performance refractories.

Data concerning the relationship between hepatitis B virus (HBV) genotypes and liver histology are scarce. The aim of this study was to compare HBV non-B and non-C genotypes according to demographic features, clinical status, HBV-DNA levels and liver histology in Rio de Janeiro. One hundred twenty one consecutive chronic HBV-infected patients were enrolled during two-year period and data were prospectively collected. Sera were tested for HBV genotyping using restriction fragment length polymorphism. Liver biopsy was obtained from patients with either increased alanine aminotransferase (ALT) or HBV-DNA levels. Genotype A was the most common, found in 82 (68%) patients, followed by F in 19 (15%), D in 17 (14%), B in one (1%) and C in two (2%). There was no association between HBV genotypes A, D and F and gender (p = 0.37), age (p = 0.78), race (p = 0.22), mode of infection (p = 0.94), HB "e" antigen status (p = 0.37) and HBV-DNA levels (p = 0.47). The ALT levels were lower in genotype D (75%) compared with A (47%) and F (55%) (p = 0.05). Liver biopsy showed lower inflammation [histological activity index (HAI) = 4] and fibrosis (F) (= 0) scores in genotype D than in genotypes A (HAI = 5, p < 0.001; F = 2, p = 0.008) or F (HAI = 5, p = 0.009; F = 2, p = 0.01). Genotype A was the most prevalent in chronic HBV-infected patients and genotype D patients presented with less intense liver disease.

The activity of Metarhizium anisopliae and Beauveria bassiana towards eggs and larvae of Tuta absoluta (Meyrick) was evaluated. Our data showed that the isolates were pathogenic to both developmental stages tested and the eggs were more susceptible than the 1st instars. The isolates URPE-6 and URPE-19 of M. anisopliae were more pathogenic to eggs and larvae, respectively. The compatibility of these two isolates with the insecticides chlorfenapyr, spinosad, indoxacarb, abamectin, and neem were evaluated. Spinosad and indoxacarb were compatible with the two M. anisopliae isolates in all tested concentrations. At the average recommended concentration, chlorfenapyr was compatible to URPE-6 and abamectin to UFPE-19. The use of entomopathogenic fungi associated with compatible insecticides may be a useful alternative to control T. absoluta.

OBJETIVO: O objetivo deste estudo é complementar os dados normativos sobre a expressão e as características do padrão alternante cíclico (CAP) em crianças, especificamente na faixa etária de 12 para 24 meses. MÉTODO: Estudo descritivo. Participantes: Doze indivíduos normais e saudáveis (6 meninas e 6 meninos, entre 12-24 meses de idade (média de 18,9±4,72 meses), foram submetidos a uma noite de gravação de polissonografia em nosso laboratório de sono pediátrico. As fases do sono e CAP foram analisados de acordo com padrão e normas internacionais. RESULTADOS: A taxa máxima encontrada em crianças de 12 a 24 meses de idade foi de (25,78%±10,18) e é caracterizada por um aumento linear de 2% ao mês, a partir de 12% em 12 meses atingindo 35% em 24 meses de idade. A duração da fase A foi de 6,93±1,06 segundos, e nas fases B foi encontrado a média de 21,44±2,31 segundos. O número de ciclos CAP foi 173,25±73,85, com um índice médio por hora de 33,55±14,61. O número de sequências CAP chegou a 25,25±9,55 por registro.Os índices dos subtipos de fases A foram (21,83%±9,68), para a A1, (2,43%±2,30) para a A3 e (1,67%±1,11) para A2. CONCLUSÃO: Nosso estudo fornece dados normativos sobre CAP em um grupo de crianças (12 a 24 meses de idade). O resultado mais saliente deste estudo é a forte correlação entre taxa do CAP e idade, mostrando que a cada mês ocorreu o aumento de 2%.

OBJECTIVE: The aim of this study is to complement existing data on the expression and characteristics of cyclic alternating pattern (CAP) in children, specifically in the 12 to 24 month age bracket. METHOD: Descriptive study. Settings: a university pediatric sleep laboratory. Participants: Twelve normal and healthy subjects (6 girls and 6 boys, mean age 18.9±4.72 months; range 12-24 months underwent a standard polysomnography night recording in our pediatric sleep laboratory. Sleep stages and CAP were analyzed according to standard international rules. RESULTS: CAP rate found in children of 12 to 24 months of age was (25.78±10.18%) and it is characterized by a linear increase of 2% per month, from 12% at 12 months reaching 35% at 24 months. With coefficient of determination R² of 0.91. The duration of A phases was 6.93±1.06 seconds, and B phases was found to last 21.44±2.31 seconds. The number of CAP cycles was 173.25±73.85 with an average index per hour of 33.55±14.61. The number of CAP sequences reached 25.25±9.55 per recording. CAP rate for the different type of A phases are (21.83±9.68%), for A1, (2.43±2.30%) for A3 and (1.67±1.11%) for A2. CONCLUSION: Our study provides normative data on CAP in a group of young children (12 to 24 months). The most salient result of this study is the strong correlation of CAP rate of 2% per month in this age group.

O experimento foi conduzido na área agrícola da Associação Brasileira de Agricultura Biodinâmica, no Município de Botucatu, SP. O objetivo do trabalho foi avaliar o desempenho da cultura do milho (Zea mays L.), variedade AL 30, em sucessão com aveia-preta (Avena strigosa Schreb.), em um sistema agroflorestal em aleias com Leucaena diversifolia (Schlecht.) Bentham e em um sistema agrícola tradicional, seguindo-se um delineamento estatístico de blocos casualizados. Os tratamentos utilizados, em ambos os sistemas, foram: T - Testemunha; F - Fertilizante; B - Biomassa da poda das aleias de L. diversifolia; e B+F - Biomassa da poda de L. diversifolia + Fertilizante. Os parâmetros avaliados foram os rendimentos de matéria seca de aveiapreta, produtividade média de grãos de milho, massa de 100 grãos de milho, altura da planta de milho e altura de inserção da espiga. Os resultados foram semelhantes aos relatados por outros autores. Concluiu-se que ambos os sistemas apresentaram viabilidade do ponto de vista produtivo e que o uso de biomassa pode substituir parcial ou totalmente a fertilização química.

The experiment was carried out in the Brazilian Association of Biodynamic Agriculture, Botucatu - São Paulo, Brazil. The aim of the work was to evaluate the productivity of corn (Zea mays L.), variety AL 30, in sequence with black oat (Avena strigosa Schreb.) under Leucaena diversifolia alley cropping agroforestry system and traditional management (without trees) following a randomized block design. Treatments were: T - Control; F - Fertilizer; B - Biomass of L. diversifolia alley cropping; B+F - Biomass of L. diversifolia alley cropping + Fertilizer. The parameters evaluated were: black oat dry matter production, grain productivity and plant height. The results were similar to those reported by other authors and concluded that both systems showed viability from the productive point of view and that the biomass use can substitute the chemical fertilizer partially or totally.

O Norte de Minas Gerais cultiva basicamente bananeira 'Prata-Anã', cultivar especialmente exigente em zinco. A possibilidade de fornecimento de Zn, sem que esse entre em contato com o solo, é importante para a região, uma vez que vários fatores levam à baixa disponibilidade do elemento fornecido via solo, como: elevado teor de matéria orgânica na camada superficial (resultante de resíduos culturais); manutenção de elevado pH do solo - acima de 6,00 - como estratégia contrária à proliferação do agente causal do mal- do-panamá; adubações frequentes com potássio e magnésio, que além de basificar o meio, diminuem a participação do Zn no equilíbrio cátion-ânion do solo, dificultando a absorção deste micronutriente pela planta. Para determinar a distribuição de biomassa e minerais na bananeira Prata-Anã, cultivada sob irrigação no norte de Minas Gerais, quando o zinco é fornecido via broto desbastado, foi conduzido um experimento no Perímetro Irrigado de Jaíba. As plantas foram adubadas com 0,00; 1,66 e 3,33 g.família-1 de Zn (0; 25 e 50 g.família-1.ano-1 de sulfato de Zn), via muda desbastada. Um mês após as adubações de outubro de 2007 e junho de 2008, avaliaram-se a produção de massa fresca (MF) e massa seca (MS), os teores e conteúdos de minerais em todos os órgãos de uma ''família'' de bananeira composta por planta-mãe com cacho + planta-filha alta + planta-neta. As doses de Zn não influíram na produção de MF e MS das plantas na primeira avaliação, enquanto na segunda avaliação observou-se efeito positivo do tratamento apenas para MF acumulada nas folhas inferiores, nas porções do terço médio e inferior do pseudocaule, e no rizoma da planta-mãe. Tanto o teor quanto o acúmulo de nutrientes nas plantas-mãe apresentaram a seguinte ordem decrescente: K > N > Ca > Mg > P > S > Fe > Zn > B > Cu. Os teores de Zn foram afetados pela dose desse micronutriente na maioria das situações estudadas. O Zn fornecido via broto desbastado ascendeu na planta-mãe, e daí se redistribuiu na ''família'' da bananeira.

In the North of Minas Gerais it is cultivated basically banana 'Prata-Anã', cultivar that requires mainly Zn. The possibility of supply of zinc, without this nutrient gets in touch with the soil, it is important for the region, since several factors take to the low availability of the element supplied by the soil, as: elevated organic matter content on the surface (from cultural residues); maintenance of high pH of the soil - above 6,00 - as strategy contrary to the proliferation of the causal agent of the Fusarium Wilt; frequent fertilizations with potassium and magnesium that, besides converting the medium into base, they reduce the participation of Zn in the balance cation/anion of the soil, hindering the absortion of this micronutrient by the plant. For determining the distribution of biomass and minerals in the banana Prata-Anã, cultivated under irrigation in the North of Minas Gerais, when zinc supplied through thinned sprout, an experiment was carried out in the Irrigated Perimeter of Jaíba. The plants were fertilized with 0,00; 1,66 and 3,33 g.family-1 of Zn, through thinned sprout. One month after the fertilizations from October, 2007 and February, 2008, the production of fresh mass (FM) and dry mass (DM) were evaluated, the contents and meanings of minerals in all of the banana ''family'' bodies composed by mother-plant with bunch + tall daughter-plant + plant-granddaughter. The doses of Zn did not influence on the production of FM and DM of the plants in the first evaluation, while in the second evaluation positive effect of the treatment was observed just for MF accumulated in the inferior leaves, in the portions of the medium third and inferior of the pseudostem, and in the mother-plant's rhizome. As much the content as the accumulation of nutrients in the mother-plants presented the following decreasing order: K > N > Ca > Mg > P > S > Fe > Zn > B > Cu. The Zn contents were affected by the dose of that micronutrient in the most of the studied situations. The zinc supplied through thinned sprout increased in the mother-plant, and then it was redistributed in the banana's ''family''.

A produção de mudas cítricas em ambiente protegido, associada ao uso de substratos, requer estratégias adequadas de manejo no viveiro. Problemas de falta e/ou excesso de nutrientes freqüentemente causam prejuízos ao setor. Em citros ocorrem diferentes respostas à disponibilidade de boro (B) para a planta e são comuns danos causados pela toxidez desse nutriente. Este trabalho teve como objetivo avaliar os efeitos da adição de B no substrato sobre a absorção e o crescimento de duas variedades de porta-enxertos de citros em fase de sementeira. O experimento foi desenvolvido em esquema fatorial, com limão 'Cravo' e citrumelo 'Swingle' e quatro doses de B misturadas ao substrato na forma de H3BO3 (0, 3, 6, e 12 g m-3 de B), em três repetições. Avaliaram-se os teores de B no substrato no início do experimento, aos 55 e 110 dias de sementeira, e o crescimento dos seedlings e a absorção de B pelas plantas nos mesmos intervalos. Os teores de B no substrato variaram entre 0,1 e 4,7 mg L-1. Aos 55 e 110 dias, houve decréscimo nos teores do nutriente nas plantas provavelmente devido às perdas do nutriente do substrato por lixiviação. Observaram-se sintomas visuais de fitotoxicidade de B nos porta-enxertos cultivados no substrato tratado com 3 g m-3 de B, quando o teor na planta foi >100 mg kg-1. O excesso de B causou redução no crescimento dos porta-enxertos. O maior crescimento e acúmulo de B na massa seca de plantas de citrumelo 'Swingle', comparado ao 'Cravo, indicam maior tolerância do primeiro à fitotoxicidade de B.

The production of citrus nursery trees under protected environment using growth media requires healthy management practices. Problems associated with deficiency and/or nutrient excess have frequently caused economic losses in the nursery. Citrus grow differently depending on boron (B) availability in the growth media, even tough B toxicity commonly cause damage to plants. This research aimed to evaluate the effects of B supply in the growth media on nutrient uptake and seedling growth of two rootstock citrus varieties. A factorial design was set up with two factors: two rootstocks (Rangpur lime and Swingle citrumelo) and four B levels added to the substrate (0, 3, 6, e 12 g m-3 B) as boric acid, with 3 replications. Boron availability in the substrate was evaluated at beginning the experiment, 55 and 110 days after rootstock seeding, as well as seedling growth and B uptake by seedlings in the same time intervals. Boron concentration in the treated substrate varied from 0.1 to 4.7 mg L-1, whereas B concentration in the whole plant tissue decreased in both evaluation periods probably because of nutrient leaching losses from substrate. Visual symptoms of B toxicity were observed for seedlings grown in substrate with B added at 3 g m-3, which were associated with B concentration in the plant tissue >100 mg kg-1. Excess B caused reduced growth of seedlings. The greater growth and B content in the dry mass of 'Swingle' compared to 'Cravo' rootstock plants denoted greater tolerance of the former to B toxicity.